UI rework: modal dialogs, inline lab editing, manual creation, content management

- Dashboard: real stats (groups, students, labs, average grade), labs/groups summary lists, no placeholder tile - Lab page: view + edit combined — metadata form in modal, condition rendered as markdown, per-level variant tables with add/edit/delete dialogs, level rename/delete, student level/variant selectors with group filter - Labs list: create-lab dialog with manual level entry (code; title lines) - Groups: create-group dialog, add-student dialog (auto password, toast card) - Content: public /learn reader is the single place; admin buttons (new article with chapter/section create-or-select, rename/delete chapters and sections, move articles between sections, import zip) appear for admins; removed separate 'Контент' admin section - Buttons use btn classes instead of nav-link - Favicon: generated SVG book icon - Security: CSRF synchronizer token interceptor (replaced spring-security in web which broke logback under nested jars), session regenerated on login, hardened session cookie, gateway actuator limited to health,info - Jackson 3: nullable-safe request DTOs for labs (FAIL_ON_NULL_FOR_PRIMITIVES) - academic: POST /labs (manual create with levels), level add/rename/delete, content chapters/sections CRUD, article create/move/delete endpoints
2026-09-11 16:00:56 +03:00
parent cca20b5416
commit 08890875e5
45 changed files with 2435 additions and 86 deletions
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/content/AssetStorage.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/content/AssetStorage.kt
@@ -0,0 +1,59 @@
+package ru.ysu.lms.academic.content
+
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.stereotype.Component
+import ru.ysu.lms.common.BadRequestException
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.UUID
+
+@Component
+class AssetStorage(@Value("\${lms.content.assets-dir:/data/content-assets}") root: String) {
+    private val rootDir: Path = Path.of(root)
+
+    init {
+        Files.createDirectories(rootDir)
+    }
+
+    data class StoredAsset(val publicName: String, val storedPath: Path, val mime: String)
+
+    fun store(originalName: String, bytes: ByteArray): StoredAsset {
+        if (bytes.size > MAX_ASSET_BYTES) {
+            throw BadRequestException("Файл $originalName слишком большой (> ${MAX_ASSET_BYTES / 1024 / 1024} МБ)")
+        }
+        val ext = originalName.substringAfterLast('.', "").lowercase()
+        val allowed = setOf("png", "jpg", "jpeg", "gif", "svg", "webp")
+        if (ext !in allowed) {
+            throw BadRequestException("Недопустимый тип файла: $originalName (разрешены ${allowed.joinToString(", ")})")
+        }
+        val publicName = "${UUID.randomUUID()}.$ext"
+        val target = rootDir.resolve(publicName).normalize()
+        if (!target.startsWith(rootDir)) {
+            throw BadRequestException("Некорректный путь файла")
+        }
+        Files.write(target, bytes)
+        return StoredAsset(publicName, target, mimeFor(ext))
+    }
+
+    fun read(publicName: String): Pair<Path, String>? {
+        val clean = publicName.substringAfterLast('/')
+        val target = rootDir.resolve(clean).normalize()
+        if (!target.startsWith(rootDir) || target.parent != rootDir) return null
+        if (!Files.isRegularFile(target)) return null
+        val ext = clean.substringAfterLast('.', "").lowercase()
+        return target to mimeFor(ext)
+    }
+
+    private fun mimeFor(ext: String): String = when (ext) {
+        "png" -> "image/png"
+        "jpg", "jpeg" -> "image/jpeg"
+        "gif" -> "image/gif"
+        "svg" -> "image/svg+xml"
+        "webp" -> "image/webp"
+        else -> "application/octet-stream"
+    }
+
+    private companion object {
+        const val MAX_ASSET_BYTES = 10 * 1024 * 1024
+    }
+}
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/content/ContentService.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/content/ContentService.kt
@@ -0,0 +1,477 @@
+package ru.ysu.lms.academic.content
+
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+import ru.ysu.lms.academic.domain.ContentArticle
+import ru.ysu.lms.academic.domain.ContentChapter
+import ru.ysu.lms.academic.domain.ContentSection
+import ru.ysu.lms.academic.repo.ContentArticleRepository
+import ru.ysu.lms.academic.repo.ContentChapterRepository
+import ru.ysu.lms.academic.repo.ContentSectionRepository
+import ru.ysu.lms.common.BadRequestException
+import ru.ysu.lms.common.NotFoundException
+import java.io.ByteArrayInputStream
+import java.util.UUID
+import java.util.zip.ZipInputStream
+
+data class ArticleTreeNode(
+    val id: String,
+    val title: String,
+    val slug: String,
+    val position: Int,
+)
+
+data class SectionTreeNode(
+    val id: String,
+    val title: String,
+    val slug: String,
+    val position: Int,
+    val articles: List<ArticleTreeNode>,
+)
+
+data class ChapterTreeNode(
+    val id: String,
+    val title: String,
+    val slug: String,
+    val position: Int,
+    val sections: List<SectionTreeNode>,
+)
+
+data class ContentTree(val chapters: List<ChapterTreeNode>)
+
+data class ContentArticleView(
+    val id: String,
+    val chapterSlug: String,
+    val chapterTitle: String,
+    val sectionSlug: String,
+    val sectionTitle: String,
+    val slug: String,
+    val title: String,
+    val bodyMd: String,
+)
+
+data class ContentImportResult(
+    val chapters: Int,
+    val sections: Int,
+    val articles: Int,
+    val assets: Int,
+)
+
+private data class ParsedArticle(
+    val path: String,
+    val chapterPos: Int,
+    val chapterDir: String,
+    val sectionPos: Int,
+    val sectionDir: String,
+    val articlePos: Int,
+    val fileTitle: String,
+    val fmSlug: String?,
+    val body: String,
+)
+
+@Service
+class ContentService(
+    private val chapters: ContentChapterRepository,
+    private val sections: ContentSectionRepository,
+    private val articles: ContentArticleRepository,
+    private val assets: AssetStorage,
+) {
+
+    @Transactional(readOnly = true)
+    fun tree(): ContentTree {
+        val chapterList = chapters.findAllByOrderByPositionAscIdAsc()
+        val sectionList = sections.findAllByOrderByPositionAscIdAsc().groupBy { it.chapterId }
+        val articleList = articles.findAllByOrderByPositionAscIdAsc().groupBy { it.sectionId }
+        return ContentTree(
+            chapterList.map { ch ->
+                ChapterTreeNode(
+                    id = ch.id.toString(),
+                    title = ch.title,
+                    slug = ch.slug,
+                    position = ch.position,
+                    sections = (sectionList[ch.id] ?: emptyList()).map { sec ->
+                        SectionTreeNode(
+                            id = sec.id.toString(),
+                            title = sec.title,
+                            slug = sec.slug,
+                            position = sec.position,
+                            articles = (articleList[sec.id] ?: emptyList()).map { a ->
+                                ArticleTreeNode(a.id.toString(), a.title, a.slug, a.position)
+                            },
+                        )
+                    },
+                )
+            },
+        )
+    }
+
+    @Transactional(readOnly = true)
+    fun findArticle(chapterSlug: String, sectionSlug: String, articleSlug: String): ContentArticleView {
+        val ch = chapters.findBySlug(chapterSlug) ?: throw NotFoundException("Глава не найдена")
+        val sec = sections.findByChapterIdAndSlug(ch.id, sectionSlug) ?: throw NotFoundException("Раздел не найден")
+        val a = articles.findBySectionIdAndSlug(sec.id, articleSlug) ?: throw NotFoundException("Статья не найдена")
+        return ContentArticleView(
+            id = a.id.toString(),
+            chapterSlug = ch.slug,
+            chapterTitle = ch.title,
+            sectionSlug = sec.slug,
+            sectionTitle = sec.title,
+            slug = a.slug,
+            title = a.title,
+            bodyMd = a.bodyMd,
+        )
+    }
+
+    @Transactional(readOnly = true)
+    fun listAll(): List<ContentArticleView> {
+        val chById = chapters.findAllByOrderByPositionAscIdAsc().associateBy { it.id }
+        val secById = sections.findAllByOrderByPositionAscIdAsc().associateBy { it.id }
+        return articles.findAllByOrderByPositionAscIdAsc().mapNotNull { a ->
+            val sec = secById[a.sectionId] ?: return@mapNotNull null
+            val ch = chById[sec.chapterId] ?: return@mapNotNull null
+            ContentArticleView(
+                id = a.id.toString(),
+                chapterSlug = ch.slug,
+                chapterTitle = ch.title,
+                sectionSlug = sec.slug,
+                sectionTitle = sec.title,
+                slug = a.slug,
+                title = a.title,
+                bodyMd = a.bodyMd,
+            )
+        }
+    }
+
+    @Transactional
+    fun updateArticle(articleId: UUID, title: String, bodyMd: String) {
+        val a = articles.findById(articleId).orElseThrow { NotFoundException("Статья не найдена") }
+        if (title.isBlank()) throw BadRequestException("Заголовок не может быть пустым")
+        a.title = title.trim()
+        a.bodyMd = bodyMd
+        articles.save(a)
+    }
+
+    @Transactional
+    fun deleteArticle(articleId: UUID) {
+        if (!articles.existsById(articleId)) throw NotFoundException("Статья не найдена")
+        articles.deleteById(articleId)
+    }
+
+    @Transactional
+    fun createChapter(title: String, slug: String?): ChapterTreeNode {
+        if (title.isBlank()) throw BadRequestException("Название главы не может быть пустым")
+        val cleanSlug = slug?.takeIf { it.isNotBlank() }?.let { slugify(it) }
+            ?: uniqueSlug(title, chapters.findAllByOrderByPositionAscIdAsc().map { it.slug }.toSet())
+        val maxPos = chapters.findAllByOrderByPositionAscIdAsc().maxOfOrNull { it.position } ?: 0
+        val ch = chapters.save(ContentChapter(title = title.trim(), slug = cleanSlug, position = maxPos + 1))
+        return ChapterTreeNode(ch.id.toString(), ch.title, ch.slug, ch.position, emptyList())
+    }
+
+    @Transactional
+    fun renameChapter(chapterId: UUID, title: String) {
+        val ch = chapters.findById(chapterId).orElseThrow { NotFoundException("Глава не найдена") }
+        if (title.isBlank()) throw BadRequestException("Название не может быть пустым")
+        ch.title = title.trim()
+        chapters.save(ch)
+    }
+
+    @Transactional
+    fun deleteChapter(chapterId: UUID) {
+        if (!chapters.existsById(chapterId)) throw NotFoundException("Глава не найдена")
+        chapters.deleteById(chapterId)
+    }
+
+    @Transactional
+    fun createSection(chapterId: UUID, title: String, slug: String?): SectionTreeNode {
+        val ch = chapters.findById(chapterId).orElseThrow { NotFoundException("Глава не найдена") }
+        if (title.isBlank()) throw BadRequestException("Название раздела не может быть пустым")
+        val siblings = sections.findByChapterIdOrderByPositionAscIdAsc(ch.id)
+        val cleanSlug = slug?.takeIf { it.isNotBlank() }?.let { slugify(it) }
+            ?: uniqueSlug(title, siblings.map { it.slug }.toSet())
+        val maxPos = siblings.maxOfOrNull { it.position } ?: 0
+        val sec = sections.save(
+            ContentSection(chapterId = ch.id, title = title.trim(), slug = cleanSlug, position = maxPos + 1),
+        )
+        return SectionTreeNode(sec.id.toString(), sec.title, sec.slug, sec.position, emptyList())
+    }
+
+    @Transactional
+    fun renameSection(sectionId: UUID, title: String) {
+        val sec = sections.findById(sectionId).orElseThrow { NotFoundException("Раздел не найден") }
+        if (title.isBlank()) throw BadRequestException("Название не может быть пустым")
+        sec.title = title.trim()
+        sections.save(sec)
+    }
+
+    @Transactional
+    fun deleteSection(sectionId: UUID) {
+        if (!sections.existsById(sectionId)) throw NotFoundException("Раздел не найден")
+        sections.deleteById(sectionId)
+    }
+
+    /** Переносит все статьи раздела в другой и удаляет раздел. */
+    @Transactional
+    fun moveArticlesAndDeleteSection(sectionId: UUID, targetSectionId: UUID) {
+        val src = sections.findById(sectionId).orElseThrow { NotFoundException("Раздел не найден") }
+        val dst = sections.findById(targetSectionId).orElseThrow { NotFoundException("Раздел назначения не найден") }
+        if (src.id == dst.id) throw BadRequestException("Раздел назначения совпадает с исходным")
+        val moving = articles.findBySectionIdOrderByPositionAscIdAsc(src.id)
+        var pos = articles.findBySectionIdOrderByPositionAscIdAsc(dst.id).maxOfOrNull { it.position } ?: 0
+        for (a in moving) {
+            pos += 1
+            a.sectionId = dst.id
+            a.position = pos
+            articles.save(a)
+        }
+        sections.delete(src)
+    }
+
+    /** Создаёт статью; если раздела нет — создаёт главу/раздел по названиям. */
+    @Transactional
+    fun createArticlePlaced(title: String, bodyMd: String, chapterId: UUID?, newChapterTitle: String?,
+                            sectionId: UUID?, newSectionTitle: String?): ContentArticleView {
+        val targetSection: ContentSection = when {
+            sectionId != null -> sections.findById(sectionId)
+                .orElseThrow { NotFoundException("Раздел не найден") }
+            !newSectionTitle.isNullOrBlank() -> {
+                val chapter: ContentChapter = when {
+                    chapterId != null -> chapters.findById(chapterId)
+                        .orElseThrow { NotFoundException("Глава не найдена") }
+                    !newChapterTitle.isNullOrBlank() -> {
+                        val node = createChapter(newChapterTitle, null)
+                        chapters.findById(UUID.fromString(node.id))
+                            .orElseThrow { NotFoundException("Глава не найдена") }
+                    }
+                    else -> throw BadRequestException("Укажите главу")
+                }
+                val node = createSection(chapter.id, newSectionTitle, null)
+                sections.findById(UUID.fromString(node.id))
+                    .orElseThrow { NotFoundException("Раздел не найден") }
+            }
+            else -> throw BadRequestException("Укажите раздел")
+        }
+        return createArticle(targetSection.id, title, bodyMd)
+    }
+
+    @Transactional
+    fun createArticle(sectionId: UUID, title: String, bodyMd: String): ContentArticleView {
+        val sec = sections.findById(sectionId).orElseThrow { NotFoundException("Раздел не найден") }
+        val ch = chapters.findById(sec.chapterId).orElseThrow { NotFoundException("Глава не найдена") }
+        if (title.isBlank()) throw BadRequestException("Заголовок не может быть пустым")
+        val siblings = articles.findBySectionIdOrderByPositionAscIdAsc(sec.id)
+        val slug = uniqueSlug(title, siblings.map { it.slug }.toSet())
+        val maxPos = siblings.maxOfOrNull { it.position } ?: 0
+        val a = articles.save(
+            ContentArticle(sectionId = sec.id, title = title.trim(), slug = slug, bodyMd = bodyMd, position = maxPos + 1),
+        )
+        return ContentArticleView(
+            id = a.id.toString(), chapterSlug = ch.slug, chapterTitle = ch.title,
+            sectionSlug = sec.slug, sectionTitle = sec.title,
+            slug = a.slug, title = a.title, bodyMd = a.bodyMd,
+        )
+    }
+
+    @Transactional
+    fun moveArticle(articleId: UUID, newSectionId: UUID): ContentArticleView {
+        val a = articles.findById(articleId).orElseThrow { NotFoundException("Статья не найдена") }
+        val sec = sections.findById(newSectionId).orElseThrow { NotFoundException("Раздел не найден") }
+        val ch = chapters.findById(sec.chapterId).orElseThrow { NotFoundException("Глава не найдена") }
+        val siblings = articles.findBySectionIdOrderByPositionAscIdAsc(sec.id)
+        a.sectionId = sec.id
+        a.position = (siblings.maxOfOrNull { it.position } ?: 0) + 1
+        articles.save(a)
+        return ContentArticleView(
+            id = a.id.toString(), chapterSlug = ch.slug, chapterTitle = ch.title,
+            sectionSlug = sec.slug, sectionTitle = sec.title,
+            slug = a.slug, title = a.title, bodyMd = a.bodyMd,
+        )
+    }
+
+    private fun uniqueSlug(title: String, taken: Set<String>): String {
+        val base = slugify(title) ?: "item"
+        if (base !in taken) return base
+        var i = 2
+        while ("$base-$i" in taken) i += 1
+        return "$base-$i"
+    }
+
+    /**
+     * Импорт zip со структурой каталогов:
+     * chapters/01-глава/01-раздел/01-статья.md (front-matter: title, slug),
+     * картинки в assets/.
+     */
+    @Transactional
+    fun importZip(filename: String, bytes: ByteArray): ContentImportResult {
+        if (!filename.lowercase().endsWith(".zip")) {
+            throw BadRequestException("Ожидается .zip архив")
+        }
+        val files = readZip(bytes)
+        if (files.isEmpty()) throw BadRequestException("Архив пуст")
+
+        val assetFiles = files.filterKeys { it.contains("/assets/") || it.startsWith("assets/") }
+        val contentFiles = files.filterKeys { k ->
+            (k.contains("/chapters/") || k.startsWith("chapters/")) && k.endsWith(".md")
+        }
+        if (contentFiles.isEmpty()) throw BadRequestException("В архиве нет каталога chapters/ с .md файлами")
+
+        val linkRewrite = mutableMapOf<String, String>()
+        for ((path, data) in assetFiles) {
+            val name = path.substringAfterLast('/')
+            if (name.isBlank()) continue
+            val stored = assets.store(name, data)
+            linkRewrite["assets/$name"] = "/api/v1/content/assets/${stored.publicName}"
+        }
+
+        val parsed = contentFiles.map { (path, data) ->
+            val clean = path.removePrefix("/").removePrefix("chapters/").removeSuffix(".md")
+            val parts = clean.split('/')
+            if (parts.size < 3) {
+                throw BadRequestException("Неверная структура: $path (ожидается chapters/NN-глава/NN-раздел/NN-статья.md)")
+            }
+            val chapterDir = parts[0]
+            val sectionDir = parts[1]
+            val fileName = parts.drop(2).joinToString("-")
+            val parsedContent = splitFrontMatter(String(data, Charsets.UTF_8))
+            ParsedArticle(
+                path = path,
+                chapterPos = positionOf(chapterDir),
+                chapterDir = titleFromDir(chapterDir),
+                sectionPos = positionOf(sectionDir),
+                sectionDir = titleFromDir(sectionDir),
+                articlePos = positionOf(fileName),
+                fileTitle = parsedContent.first["title"] ?: titleFromDir(fileName),
+                fmSlug = parsedContent.first["slug"],
+                body = parsedContent.second,
+            )
+        }.sortedWith(
+            compareBy(
+                { it.chapterPos },
+                { it.chapterDir },
+                { it.sectionPos },
+                { it.sectionDir },
+                { it.articlePos },
+            ),
+        )
+
+        var chCount = 0
+        var secCount = 0
+        var artCount = 0
+        var currentChapter: ContentChapter? = null
+        var currentSection: ContentSection? = null
+
+        for (p in parsed) {
+            if (currentChapter?.title != p.chapterDir) {
+                val slug = chapterSlug(p) ?: "chapter-${chCount + 1}"
+                currentChapter = chapters.findBySlug(slug) ?: chapters.save(
+                    ContentChapter(title = p.chapterDir, slug = slug, position = p.chapterPos),
+                )
+                chCount += 1
+                currentSection = null
+            }
+            val chapter = currentChapter ?: throw BadRequestException("Не удалось определить главу")
+            if (currentSection?.title != p.sectionDir) {
+                val slug = sectionSlug(p) ?: "section-${secCount + 1}"
+                currentSection = sections.findByChapterIdAndSlug(chapter.id, slug) ?: sections.save(
+                    ContentSection(chapterId = chapter.id, title = p.sectionDir, slug = slug, position = p.sectionPos),
+                )
+                secCount += 1
+            }
+            val section = currentSection ?: throw BadRequestException("Не удалось определить раздел")
+
+            var body = p.body
+            for ((from, to) in linkRewrite) {
+                body = body.replace(from, to)
+            }
+            val slug = p.fmSlug?.takeIf { it.isNotBlank() }
+                ?: articleSlug(p)
+                ?: "article-${artCount + 1}"
+            val existing = articles.findBySectionIdAndSlug(section.id, slug)
+            val article = (existing ?: ContentArticle(sectionId = section.id, slug = slug)).apply {
+                title = p.fileTitle
+                bodyMd = body
+                position = p.articlePos
+            }
+            articles.save(article)
+            artCount += 1
+        }
+
+        return ContentImportResult(chapters = chCount, sections = secCount, articles = artCount, assets = linkRewrite.size)
+    }
+
+    private fun chapterSlug(p: ParsedArticle): String? =
+        slugify("%02d".format(p.chapterPos) + "-" + p.chapterDir)
+
+    private fun sectionSlug(p: ParsedArticle): String? =
+        slugify("%02d".format(p.sectionPos) + "-" + p.sectionDir)
+
+    private fun articleSlug(p: ParsedArticle): String? =
+        slugify("%02d".format(p.articlePos) + "-" + p.fileTitle)
+
+    private fun readZip(bytes: ByteArray): Map<String, ByteArray> {
+        val result = mutableMapOf<String, ByteArray>()
+        ZipInputStream(ByteArrayInputStream(bytes)).use { zis ->
+            var entry = zis.nextEntry
+            while (entry != null) {
+                if (!entry.isDirectory) {
+                    result[entry.name.removePrefix("/")] = zis.readAllBytes()
+                }
+                entry = zis.nextEntry
+            }
+        }
+        return result
+    }
+
+    private fun splitFrontMatter(content: String): Pair<Map<String, String>, String> {
+        if (!content.startsWith("---")) return emptyMap<String, String>() to content
+        val lines = content.lines()
+        val end = lines.withIndex()
+            .firstOrNull { it.index != 0 && it.value.trim() == "---" }
+            ?.index ?: return emptyMap<String, String>() to content
+        val fm = mutableMapOf<String, String>()
+        for (line in lines.subList(1, end)) {
+            val parts = line.split(":", limit = 2)
+            if (parts.size == 2) {
+                val v = parts[1].trim()
+                val unquoted = if (v.length >= 2 && v.first() == '"' && v.last() == '"') {
+                    v.substring(1, v.length - 1)
+                } else {
+                    v
+                }
+                fm[parts[0].trim()] = unquoted
+            }
+        }
+        return fm to lines.drop(end + 1).joinToString("\n").trim()
+    }
+
+    private fun positionOf(name: String): Int {
+        val m = Regex("^(\\d{1,3})[-_]").find(name.substringAfterLast('/'))
+        return m?.groupValues?.get(1)?.toIntOrNull() ?: 999
+    }
+
+    private fun titleFromDir(dir: String): String {
+        val raw = dir.substringAfterLast('/')
+            .replace(Regex("^\\d{1,3}[-_]"), "")
+            .replace('_', ' ')
+        return raw.ifBlank { dir }
+    }
+
+    private fun slugify(value: String): String? {
+        val translit = TRANSLIT.entries.fold(value.lowercase()) { acc, (from, to) -> acc.replace(from, to) }
+        val slug = translit
+            .replace(Regex("\\s+"), "-")
+            .replace(Regex("[^a-z0-9-]"), "")
+            .replace(Regex("-+"), "-")
+            .trim('-')
+        return slug.ifBlank { null }
+    }
+
+    private companion object {
+        val TRANSLIT = mapOf(
+            "а" to "a", "б" to "b", "в" to "v", "г" to "g", "д" to "d", "е" to "e", "ё" to "e",
+            "ж" to "zh", "з" to "z", "и" to "i", "й" to "y", "к" to "k", "л" to "l", "м" to "m",
+            "н" to "n", "о" to "o", "п" to "p", "р" to "r", "с" to "s", "т" to "t", "у" to "u",
+            "ф" to "f", "х" to "h", "ц" to "c", "ч" to "ch", "ш" to "sh", "щ" to "sch", "ъ" to "",
+            "ы" to "y", "ь" to "", "э" to "e", "ю" to "yu", "я" to "ya",
+        )
+    }
+}
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/controller/ContentAdminController.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/controller/ContentAdminController.kt
@@ -0,0 +1,106 @@
+package ru.ysu.lms.academic.controller
+
+import org.springframework.http.ResponseEntity
+import org.springframework.security.access.prepost.PreAuthorize
+import org.springframework.web.bind.annotation.DeleteMapping
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.PutMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RequestParam
+import org.springframework.web.bind.annotation.RestController
+import org.springframework.web.multipart.MultipartFile
+import ru.ysu.lms.academic.content.ContentImportResult
+import ru.ysu.lms.academic.content.ContentService
+import ru.ysu.lms.common.BadRequestException
+import java.util.UUID
+
+@RestController
+@RequestMapping("/api/v1/content")
+@PreAuthorize("hasAuthority('ROLE_ADMIN')")
+class ContentAdminController(private val contentService: ContentService) {
+
+    data class ArticleUpdatePayload(val title: String, val bodyMd: String)
+    data class ArticleCreatePayload(
+        val chapterId: String? = null,
+        val sectionId: String? = null,
+        val newChapterTitle: String? = null,
+        val newSectionTitle: String? = null,
+        val title: String,
+        val bodyMd: String = "",
+    )
+    data class ArticleMovePayload(val sectionId: String)
+    data class TitlePayload(val title: String)
+    data class ChapterCreatePayload(val title: String, val slug: String? = null)
+    data class SectionCreatePayload(val title: String, val slug: String? = null)
+
+    @PostMapping("/import")
+    fun import(@RequestParam("file") file: MultipartFile): ContentImportResult {
+        if (file.isEmpty) throw BadRequestException("Выберите файл")
+        return contentService.importZip(file.originalFilename ?: "content.zip", file.bytes)
+    }
+
+    @GetMapping("/articles")
+    fun list() = contentService.listAll()
+
+    @PostMapping("/chapters")
+    fun createChapter(@RequestBody body: ChapterCreatePayload) = contentService.createChapter(body.title, body.slug)
+
+    @PutMapping("/chapters/{id}")
+    fun renameChapter(@PathVariable id: UUID, @RequestBody body: TitlePayload) =
+        contentService.renameChapter(id, body.title)
+
+    @DeleteMapping("/chapters/{id}")
+    fun deleteChapter(@PathVariable id: UUID): ResponseEntity<Void> {
+        contentService.deleteChapter(id)
+        return ResponseEntity.noContent().build()
+    }
+
+    @PostMapping("/sections")
+    fun createSection(@RequestParam chapterId: UUID, @RequestBody body: SectionCreatePayload) =
+        contentService.createSection(chapterId, body.title, body.slug)
+
+    @PutMapping("/sections/{id}")
+    fun renameSection(@PathVariable id: UUID, @RequestBody body: TitlePayload) =
+        contentService.renameSection(id, body.title)
+
+    @DeleteMapping("/sections/{id}")
+    fun deleteSection(
+        @PathVariable id: UUID,
+        @RequestParam(required = false) moveTo: UUID?,
+    ): ResponseEntity<Void> {
+        if (moveTo != null) {
+            contentService.moveArticlesAndDeleteSection(id, moveTo)
+        } else {
+            contentService.deleteSection(id)
+        }
+        return ResponseEntity.noContent().build()
+    }
+
+    @PostMapping("/articles")
+    fun createArticle(@RequestBody body: ArticleCreatePayload) = contentService.createArticlePlaced(
+        title = body.title,
+        bodyMd = body.bodyMd,
+        chapterId = body.chapterId?.let { UUID.fromString(it) },
+        newChapterTitle = body.newChapterTitle,
+        sectionId = body.sectionId?.let { UUID.fromString(it) },
+        newSectionTitle = body.newSectionTitle,
+    )
+
+    @PutMapping("/articles/{id}")
+    fun update(@PathVariable id: UUID, @RequestBody body: ArticleUpdatePayload) {
+        contentService.updateArticle(id, body.title, body.bodyMd)
+    }
+
+    @PostMapping("/articles/{id}/move")
+    fun move(@PathVariable id: UUID, @RequestBody body: ArticleMovePayload) =
+        contentService.moveArticle(id, UUID.fromString(body.sectionId))
+
+    @DeleteMapping("/articles/{id}")
+    fun delete(@PathVariable id: UUID): ResponseEntity<Void> {
+        contentService.deleteArticle(id)
+        return ResponseEntity.noContent().build()
+    }
+}
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/controller/ContentPublicController.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/controller/ContentPublicController.kt
@@ -0,0 +1,60 @@
+package ru.ysu.lms.academic.controller
+
+import org.springframework.core.io.FileSystemResource
+import org.springframework.http.MediaType
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RestController
+import ru.ysu.lms.academic.content.AssetStorage
+import ru.ysu.lms.academic.content.ContentService
+import java.nio.file.Files
+
+/** Публичное чтение учебных материалов — доступно без аутентификации. */
+@RestController
+@RequestMapping("/api/v1/content")
+class ContentPublicController(
+    private val contentService: ContentService,
+    private val assetStorage: AssetStorage,
+) {
+
+    @GetMapping("/tree")
+    fun tree() = contentService.tree()
+
+    @GetMapping("/{chapter}/{section}/{article}")
+    fun article(
+        @PathVariable chapter: String,
+        @PathVariable section: String,
+        @PathVariable article: String,
+    ): ContentArticleViewDto {
+        val a = contentService.findArticle(chapter, section, article)
+        return ContentArticleViewDto(
+            id = a.id, chapterSlug = a.chapterSlug, chapterTitle = a.chapterTitle,
+            sectionSlug = a.sectionSlug, sectionTitle = a.sectionTitle,
+            slug = a.slug, title = a.title, bodyMd = a.bodyMd,
+        )
+    }
+
+    data class ContentArticleViewDto(
+        val id: String,
+        val chapterSlug: String,
+        val chapterTitle: String,
+        val sectionSlug: String,
+        val sectionTitle: String,
+        val slug: String,
+        val title: String,
+        val bodyMd: String,
+    )
+
+    @GetMapping("/assets/{name}")
+    fun asset(@PathVariable name: String): ResponseEntity<FileSystemResource> {
+        val (path, mime) = assetStorage.read(name)
+            ?: return ResponseEntity.notFound().build()
+        val media = runCatching { MediaType.parseMediaType(mime) }.getOrElse { MediaType.APPLICATION_OCTET_STREAM }
+        return ResponseEntity.ok()
+            .contentType(media)
+            .cacheControl(org.springframework.http.CacheControl.maxAge(java.time.Duration.ofDays(7)))
+            .body(FileSystemResource(path))
+    }
+}
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/controller/LabController.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/controller/LabController.kt
@@ -54,4 +54,28 @@ class LabController(private val labService: LabService) {
    @PreAuthorize("hasAuthority('ROLE_ADMIN')")
    fun deleteVariant(@PathVariable id: UUID, @PathVariable variantId: UUID): LabDetail =
        labService.deleteVariant(id, variantId)
+
+    @PostMapping
+    @PreAuthorize("hasAuthority('ROLE_ADMIN')")
+    fun create(@Valid @RequestBody body: LabCreateRequest): LabDetail = labService.create(body)
+
+    @PostMapping("/{id}/levels")
+    @PreAuthorize("hasAuthority('ROLE_ADMIN')")
+    fun addLevel(@PathVariable id: UUID, @Valid @RequestBody body: LevelSaveRequest): LabDetail {
+        labService.addLevel(id, body)
+        return labService.detail(id)
+    }
+
+    @PutMapping("/{id}/levels/{levelId}")
+    @PreAuthorize("hasAuthority('ROLE_ADMIN')")
+    fun renameLevel(
+        @PathVariable id: UUID,
+        @PathVariable levelId: UUID,
+        @Valid @RequestBody body: LevelRenameRequest,
+    ): LabDetail = labService.renameLevel(id, levelId, body)
+
+    @DeleteMapping("/{id}/levels/{levelId}")
+    @PreAuthorize("hasAuthority('ROLE_ADMIN')")
+    fun deleteLevel(@PathVariable id: UUID, @PathVariable levelId: UUID): LabDetail =
+        labService.deleteLevel(id, levelId)
 }
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/domain/Content.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/domain/Content.kt
@@ -0,0 +1,38 @@
+package ru.ysu.lms.academic.domain
+
+import jakarta.persistence.Column
+import jakarta.persistence.Entity
+import jakarta.persistence.Id
+import jakarta.persistence.Table
+import ru.ysu.lms.common.Ids
+import java.util.UUID
+
+@Entity
+@Table(name = "chapters")
+class ContentChapter(
+    @Id var id: UUID = Ids.v7(),
+    @Column(nullable = false, length = 200) var title: String = "",
+    @Column(nullable = false, unique = true, length = 200) var slug: String = "",
+    @Column(nullable = false) var position: Int = 0,
+)
+
+@Entity
+@Table(name = "sections")
+class ContentSection(
+    @Id var id: UUID = Ids.v7(),
+    @Column(nullable = false) var chapterId: UUID = UUID(0, 0),
+    @Column(nullable = false, length = 200) var title: String = "",
+    @Column(nullable = false, length = 200) var slug: String = "",
+    @Column(nullable = false) var position: Int = 0,
+)
+
+@Entity
+@Table(name = "articles")
+class ContentArticle(
+    @Id var id: UUID = Ids.v7(),
+    @Column(nullable = false) var sectionId: UUID = UUID(0, 0),
+    @Column(nullable = false, length = 200) var title: String = "",
+    @Column(nullable = false, length = 200) var slug: String = "",
+    @Column(nullable = false) var bodyMd: String = "",
+    @Column(nullable = false) var position: Int = 0,
+)
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/lab/LabDtos.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/lab/LabDtos.kt
@@ -16,7 +16,7 @@ data class LabLevelMeta(
    val code: String,
    val title: String,
    val description: String = "",
-    val position: Int = 0,
+    val position: Int? = null,
    val pointsMax: BigDecimal? = null,
 )

@@ -84,14 +84,39 @@ data class LabUpdateRequest(
    val title: String,
    val deadlineAt: String? = null,
    val defenseAt: String? = null,
-    val pointsMax: BigDecimal,
-    val status: String,
-    val descriptionMd: String,
+    val pointsMax: BigDecimal? = null,
+    val status: String? = null,
+    val descriptionMd: String? = null,
 )

 data class VariantSaveRequest(
    val labLevelId: String,
    val number: String,
+    val title: String? = null,
+    val statementMd: String? = null,
+)
+
+data class LevelSaveRequest(
+    val code: String,
+    val title: String? = null,
+    val description: String? = null,
+    val position: Int? = null,
+)
+
+data class LabCreateRequest(
+    val number: Int? = null,
+    val title: String? = null,
+    val semesterTitle: String? = null,
+    val semesterYear: Int? = null,
+    val deadlineAt: String? = null,
+    val defenseAt: String? = null,
+    val pointsMax: BigDecimal? = null,
+    val status: String? = null,
+    val descriptionMd: String? = null,
+    val levels: List<LevelSaveRequest> = emptyList(),
+)
+
+data class LevelRenameRequest(
    val title: String,
-    val statementMd: String,
+    val description: String? = null,
 )
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/lab/LabService.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/lab/LabService.kt
@@ -4,6 +4,7 @@ import org.springframework.stereotype.Service
 import org.springframework.transaction.annotation.Transactional
 import ru.ysu.lms.academic.domain.Lab
 import ru.ysu.lms.academic.domain.LabLevel
+import ru.ysu.lms.academic.domain.Semester
 import ru.ysu.lms.academic.domain.Variant
 import ru.ysu.lms.academic.repo.LabLevelRepository
 import ru.ysu.lms.academic.repo.LabRepository
@@ -11,6 +12,7 @@ import ru.ysu.lms.academic.repo.SemesterRepository
 import ru.ysu.lms.academic.repo.VariantRepository
 import ru.ysu.lms.common.NotFoundException
 import ru.ysu.lms.common.BadRequestException
+import ru.ysu.lms.common.ConflictException
 import java.math.BigDecimal
 import java.time.Instant
 import java.time.LocalDateTime
@@ -53,8 +55,8 @@ class LabService(
                lab = lab,
                code = meta.code,
                title = meta.title,
-                description = meta.description,
-                position = meta.position,
+                description = meta.description.orEmpty(),
+                position = meta.position ?: 0,
                pointsMax = meta.pointsMax,
            ))
        }
@@ -147,9 +149,9 @@ class LabService(
        lab.title = request.title.trim()
        lab.deadlineAt = parseInstant(request.deadlineAt)
        lab.defenseAt = parseInstant(request.defenseAt)
-        lab.pointsMax = request.pointsMax
-        lab.status = request.status
-        lab.descriptionMd = request.descriptionMd
+        lab.pointsMax = request.pointsMax ?: lab.pointsMax
+        lab.status = request.status ?: lab.status
+        lab.descriptionMd = request.descriptionMd.orEmpty()
        labs.save(lab)
        return detail(labId)
    }
@@ -159,10 +161,10 @@ class LabService(
        val variant = variantsRepo.findById(variantId)
            .orElseThrow { NotFoundException("Вариант не найден") }
        if (variant.lab?.id != labId) throw NotFoundException("Вариант не найден")
-        if (request.number.isBlank()) throw BadRequestException("Номер варианта не может быть пустым")
+        if (request.number.isNullOrBlank()) throw BadRequestException("Номер варианта не может быть пустым")
        variant.number = request.number.trim()
-        variant.title = request.title.trim()
-        variant.statementMd = request.statementMd
+        variant.title = request.title.orEmpty().trim()
+        variant.statementMd = request.statementMd.orEmpty()
        request.labLevelId.takeIf { it.isNotBlank() }?.let { levelId ->
            variant.labLevel = labLevels.findById(UUID.fromString(levelId))
                .orElseThrow { BadRequestException("Уровень не найден") }
@@ -174,15 +176,15 @@ class LabService(
    @Transactional
    fun addVariant(labId: UUID, request: VariantSaveRequest): LabDetail {
        val lab = labs.findById(labId).orElseThrow { NotFoundException("Лабораторная не найдена") }
-        if (request.number.isBlank()) throw BadRequestException("Номер варианта не может быть пустым")
+        if (request.number.isNullOrBlank()) throw BadRequestException("Номер варианта не может быть пустым")
        val level = labLevels.findById(UUID.fromString(request.labLevelId))
            .orElseThrow { BadRequestException("Уровень не найден") }
        variantsRepo.save(Variant(
            lab = lab,
            labLevel = level,
            number = request.number.trim(),
-            title = request.title.trim(),
-            statementMd = request.statementMd,
+            title = request.title.orEmpty().trim(),
+            statementMd = request.statementMd.orEmpty(),
        ))
        return detail(labId)
    }
@@ -196,6 +198,88 @@ class LabService(
        return detail(labId)
    }

+    @Transactional
+    fun create(request: LabCreateRequest): LabDetail {
+        if (request.title.isNullOrBlank()) throw BadRequestException("Название не может быть пустым")
+        if ((request.number ?: 0) <= 0) throw BadRequestException("Номер лабораторной должен быть положительным")
+        val semester = findOrCreateSemester(request.semesterTitle.orEmpty(), request.semesterYear ?: 0)
+        if (labs.existsByNumberAndSemesterId(request.number ?: 0, semester.id)) {
+            throw ConflictException("Лабораторная №${request.number} уже существует в этом семестре")
+        }
+        val lab = labs.save(
+            Lab(
+                number = request.number ?: 0,
+                title = request.title.orEmpty().trim(),
+                semester = semester,
+                descriptionMd = request.descriptionMd.orEmpty(),
+                deadlineAt = parseInstant(request.deadlineAt),
+                defenseAt = parseInstant(request.defenseAt),
+                pointsMax = request.pointsMax ?: BigDecimal(5),
+                status = request.status ?: "draft",
+            ),
+        )
+        val levelMetas = request.levels.ifEmpty {
+            listOf(LevelSaveRequest(code = "basic", title = "Основная группа"))
+        }
+        levelMetas.forEachIndexed { index, meta ->
+            if (meta.code.isNullOrBlank()) throw BadRequestException("Код уровня не может быть пустым")
+            labLevels.save(
+                LabLevel(
+                    lab = lab,
+                    code = meta.code.trim(),
+                    title = meta.title.orEmpty().ifBlank { meta.code },
+                    description = meta.description.orEmpty(),
+                    position = meta.position?.takeIf { it > 0 } ?: index + 1,
+                ),
+            )
+        }
+        return detail(lab.id)
+    }
+
+    @Transactional
+    fun renameLevel(labId: UUID, levelId: UUID, request: LevelRenameRequest): LabDetail {
+        val level = labLevels.findById(levelId).orElseThrow { NotFoundException("Уровень не найден") }
+        if (level.lab?.id != labId) throw NotFoundException("Уровень не найден")
+        level.title = request.title.ifBlank { level.title }
+        level.description = request.description.orEmpty()
+        labLevels.save(level)
+        return detail(labId)
+    }
+
+    @Transactional
+    fun deleteLevel(labId: UUID, levelId: UUID): LabDetail {
+        val level = labLevels.findById(levelId).orElseThrow { NotFoundException("Уровень не найден") }
+        if (level.lab?.id != labId) throw NotFoundException("Уровень не найден")
+        if (variantsRepo.findByLabIdOrderByNumber(labId).any { it.labLevel?.id == levelId }) {
+            throw ConflictException("У уровня есть варианты — сначала удалите их")
+        }
+        labLevels.delete(level)
+        return detail(labId)
+    }
+
+    @Transactional
+    fun addLevel(labId: UUID, request: LevelSaveRequest) {
+        val lab = labs.findById(labId).orElseThrow { NotFoundException("Лабораторная не найдена") }
+        if (request.code.isNullOrBlank()) throw BadRequestException("Код уровня не может быть пустым")
+        val existing = labLevels.findByLabIdOrderByPosition(labId)
+        labLevels.save(
+            LabLevel(
+                lab = lab,
+                code = request.code.trim(),
+                title = request.title.orEmpty().ifBlank { request.code },
+                description = request.description.orEmpty(),
+                position = request.position?.takeIf { it > 0 } ?: (existing.size + 1),
+            ),
+        )
+    }
+
+    private fun findOrCreateSemester(title: String, year: Int): Semester {
+        semesters.findFirstByActiveTrue()?.let { return it }
+        val t = title.ifBlank { "осень" }
+        val y = if (year > 0) year else java.time.LocalDate.now().year
+        return semesters.save(Semester(title = t, year = y, active = true))
+    }
+
    private fun parseInstant(value: String?): Instant? {
        val v = value?.takeIf { it.isNotBlank() } ?: return null
        return runCatching { Instant.parse(v) }
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/repo/ContentRepositories.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/repo/ContentRepositories.kt
@@ -0,0 +1,24 @@
+package ru.ysu.lms.academic.repo
+
+import org.springframework.data.jpa.repository.JpaRepository
+import ru.ysu.lms.academic.domain.ContentArticle
+import ru.ysu.lms.academic.domain.ContentChapter
+import ru.ysu.lms.academic.domain.ContentSection
+import java.util.UUID
+
+interface ContentChapterRepository : JpaRepository<ContentChapter, UUID> {
+    fun findAllByOrderByPositionAscIdAsc(): List<ContentChapter>
+    fun findBySlug(slug: String): ContentChapter?
+}
+
+interface ContentSectionRepository : JpaRepository<ContentSection, UUID> {
+    fun findAllByOrderByPositionAscIdAsc(): List<ContentSection>
+    fun findByChapterIdOrderByPositionAscIdAsc(chapterId: UUID): List<ContentSection>
+    fun findByChapterIdAndSlug(chapterId: UUID, slug: String): ContentSection?
+}
+
+interface ContentArticleRepository : JpaRepository<ContentArticle, UUID> {
+    fun findBySectionIdOrderByPositionAscIdAsc(sectionId: UUID): List<ContentArticle>
+    fun findBySectionIdAndSlug(sectionId: UUID, slug: String): ContentArticle?
+    fun findAllByOrderByPositionAscIdAsc(): List<ContentArticle>
+}
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/repo/LabRepository.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/repo/LabRepository.kt
@@ -6,4 +6,5 @@ import java.util.UUID

 interface LabRepository : JpaRepository<Lab, UUID> {
    fun findAllByOrderByNumberAsc(): List<Lab>
+    fun existsByNumberAndSemesterId(number: Int, semesterId: UUID): Boolean
 }
--- a/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/security/SecurityConfig.kt
+++ b/services/academic-service/src/main/kotlin/ru/ysu/lms/academic/security/SecurityConfig.kt
@@ -43,7 +43,14 @@ class SecurityConfig {
            .cors { it.disable() }
            .sessionManagement { it.sessionCreationPolicy(SessionCreationPolicy.STATELESS) }
            .authorizeHttpRequests { auth ->
-                auth.requestMatchers("/actuator/**", "/v3/api-docs/**", "/swagger-ui/**").permitAll()
+                auth.requestMatchers(
+                    "/actuator/**",
+                    "/v3/api-docs/**",
+                    "/swagger-ui/**",
+                    "/api/v1/content/tree",
+                    "/api/v1/content/assets/**",
+                    "/api/v1/content/{chapter}/{section}/{article}",
+                ).permitAll()
                auth.anyRequest().authenticated()
            }
            .oauth2ResourceServer { oauth ->
--- a/services/academic-service/src/main/resources/application.yml
+++ b/services/academic-service/src/main/resources/application.yml
@@ -35,3 +35,7 @@ management:
 springdoc:
  api-docs:
    path: /v3/api-docs
+
+lms:
+  content:
+    assets-dir: ${LMS_CONTENT_ASSETS_DIR:data/content-assets}
--- a/services/academic-service/src/main/resources/db/migration/V4__content.sql
+++ b/services/academic-service/src/main/resources/db/migration/V4__content.sql
@@ -0,0 +1,29 @@
+-- Content: chapters -> sections -> articles (public learning materials).
+-- The previously unused courses table is replaced by the chapters/sections model.
+
+ALTER TABLE articles DROP CONSTRAINT IF EXISTS articles_course_slug_unique;
+ALTER TABLE articles DROP CONSTRAINT IF EXISTS articles_course_id_fkey;
+ALTER TABLE articles RENAME COLUMN course_id TO section_id;
+
+CREATE TABLE chapters (
+    id      uuid PRIMARY KEY DEFAULT uuidv7(),
+    title   varchar(200) NOT NULL,
+    slug    varchar(200) NOT NULL UNIQUE,
+    position integer NOT NULL DEFAULT 0
+);
+
+CREATE TABLE sections (
+    id         uuid PRIMARY KEY DEFAULT uuidv7(),
+    chapter_id uuid NOT NULL REFERENCES chapters(id) ON DELETE CASCADE,
+    title      varchar(200) NOT NULL,
+    slug       varchar(200) NOT NULL,
+    position   integer NOT NULL DEFAULT 0,
+    CONSTRAINT sections_chapter_slug_unique UNIQUE (chapter_id, slug)
+);
+
+ALTER TABLE articles
+    ADD CONSTRAINT articles_section_fk FOREIGN KEY (section_id) REFERENCES sections(id) ON DELETE CASCADE;
+ALTER TABLE articles
+    ADD CONSTRAINT articles_section_slug_unique UNIQUE (section_id, slug);
+
+DROP TABLE IF EXISTS courses;