import { stripHtml } from '../services/word-count'
import type { Chapter } from '../../shared/types'
import type { ExportMatrixOptions } from '../../shared/export-matrix'
import { ChapterRepository } from '../db/repositories/chapter.repo'
import { VolumeRepository } from '../db/repositories/volume.repo'
import { BookmarkRepository } from '../db/repositories/bookmark.repo'
import { SnapshotRepository } from '../db/repositories/snapshot.repo'
import type { SqliteDb } from '../db/types'

export interface ExportChapterBlock {
  id: string
  title: string
  volumeName: string
  paragraphs: string[]
  annotations: string[]
  hasAiContent: boolean
}

export function htmlToPlainParagraphs(html: string): string[] {
  const trimmed = html.trim()
  if (!trimmed) return []
  const pMatches = trimmed.match(/<p[^>]*>([\s\S]*?)<\/p>/gi)
  if (pMatches && pMatches.length > 0) {
    return pMatches.map((p) => stripHtml(p).trim()).filter(Boolean)
  }
  const plain = stripHtml(trimmed)
  if (!plain.trim()) return []
  return plain
    .split(/\n{2,}/)
    .map((s) => s.trim())
    .filter(Boolean)
}

export function htmlToMarkdownParagraphs(html: string): string[] {
  return htmlToPlainParagraphs(html)
}

export function resolveExportChapters(
  db: SqliteDb,
  scope: 'chapter' | 'volume' | 'book',
  scopeId?: string
): Chapter[] {
  const chapterRepo = new ChapterRepository(db)
  const all = chapterRepo.list().sort((a, b) => a.sortOrder - b.sortOrder)
  if (scope === 'chapter') {
    if (!scopeId) throw new Error('Chapter scope requires scopeId')
    const ch = chapterRepo.get(scopeId)
    return ch ? [ch] : []
  }
  if (scope === 'volume') {
    if (!scopeId) throw new Error('Volume scope requires scopeId')
    return all.filter((c) => c.volumeId === scopeId)
  }
  return all
}

export function buildExportBlocks(
  db: SqliteDb,
  chapters: Chapter[],
  options: ExportMatrixOptions = {}
): ExportChapterBlock[] {
  const volumeRepo = new VolumeRepository(db)
  const bookmarkRepo = new BookmarkRepository(db)
  const snapshotRepo = new SnapshotRepository(db)
  const volumes = new Map(volumeRepo.list().map((v) => [v.id, v.name]))

  return chapters.map((ch) => {
    const annotations =
      options.includeAnnotations === true
        ? bookmarkRepo.listByChapter(ch.id).map((b) => `[${b.landmarkType}] ${b.label}`)
        : []
    const hasAiContent =
      options.markAiContent === true && snapshotRepo.list(ch.id).some((s) => s.type === 'ai')
    return {
      id: ch.id,
      title: ch.title,
      volumeName: (ch.volumeId && volumes.get(ch.volumeId)) || '',
      paragraphs: htmlToPlainParagraphs(ch.content),
      annotations,
      hasAiContent
    }
  })
}

export function buildTxtExport(blocks: ExportChapterBlock[]): string {
  return blocks
    .map((block) => {
      const lines: string[] = [`# ${block.title}`]
      if (block.hasAiContent) lines.push('[AI生成内容]', '')
      lines.push(...block.paragraphs)
      if (block.annotations.length > 0) {
        lines.push('', '--- 批注 ---', ...block.annotations.map((a) => `- ${a}`))
      }
      return lines.join('\n')
    })
    .join('\n\n')
}

export function buildMdExport(blocks: ExportChapterBlock[]): string {
  return blocks
    .map((block) => {
      const lines: string[] = [`# ${block.title}`]
      if (block.hasAiContent) lines.push('', '> *AI 生成内容*', '')
      lines.push(...block.paragraphs)
      if (block.annotations.length > 0) {
        lines.push('', '## 批注', ...block.annotations.map((a) => `- ${a}`))
      }
      return lines.join('\n')
    })
    .join('\n\n')
}