/**
 * Soul创业实验 - 文章数据API
 * 用于存储和获取章节数据
 */

import { NextResponse } from 'next/server'
import fs from 'fs'
import path from 'path'

// 文章数据结构
interface Section {
  id: string
  title: string
  isFree: boolean
  price: number
  content?: string
  filePath?: string
}

interface Chapter {
  id: string
  title: string
  sections: Section[]
}

interface Part {
  id: string
  number: string
  title: string
  subtitle: string
  chapters: Chapter[]
}

// 书籍目录结构映射
const BOOK_STRUCTURE = [
  {
    id: 'part-1',
    number: '一',
    title: '真实的人',
    subtitle: '人与人之间的底层逻辑',
    folder: '第一篇｜真实的人',
    chapters: [
      { id: 'chapter-1', title: '第1章｜人与人之间的底层逻辑', folder: '第1章｜人与人之间的底层逻辑' },
      { id: 'chapter-2', title: '第2章｜人性困境案例', folder: '第2章｜人性困境案例' }
    ]
  },
  {
    id: 'part-2',
    number: '二',
    title: '真实的行业',
    subtitle: '电商、内容、传统行业解析',
    folder: '第二篇｜真实的行业',
    chapters: [
      { id: 'chapter-3', title: '第3章｜电商篇', folder: '第3章｜电商篇' },
      { id: 'chapter-4', title: '第4章｜内容商业篇', folder: '第4章｜内容商业篇' },
      { id: 'chapter-5', title: '第5章｜传统行业篇', folder: '第5章｜传统行业篇' }
    ]
  },
  {
    id: 'part-3',
    number: '三',
    title: '真实的错误',
    subtitle: '我和别人犯过的错',
    folder: '第三篇｜真实的错误',
    chapters: [
      { id: 'chapter-6', title: '第6章｜我人生错过的4件大钱', folder: '第6章｜我人生错过的4件大钱' },
      { id: 'chapter-7', title: '第7章｜别人犯的错误', folder: '第7章｜别人犯的错误' }
    ]
  },
  {
    id: 'part-4',
    number: '四',
    title: '真实的赚钱',
    subtitle: '底层结构与真实案例',
    folder: '第四篇｜真实的赚钱',
    chapters: [
      { id: 'chapter-8', title: '第8章｜底层结构', folder: '第8章｜底层结构' },
      { id: 'chapter-9', title: '第9章｜我在Soul上亲访的赚钱案例', folder: '第9章｜我在Soul上亲访的赚钱案例' }
    ]
  },
  {
    id: 'part-5',
    number: '五',
    title: '真实的社会',
    subtitle: '未来职业与商业生态',
    folder: '第五篇｜真实的社会',
    chapters: [
      { id: 'chapter-10', title: '第10章｜未来职业的变化趋势', folder: '第10章｜未来职业的变化趋势' },
      { id: 'chapter-11', title: '第11章｜中国社会商业生态的未来', folder: '第11章｜中国社会商业生态的未来' }
    ]
  }
]

// 免费章节ID
const FREE_SECTIONS = ['1.1', 'preface', 'epilogue', 'appendix-1', 'appendix-2', 'appendix-3']

// 从book目录读取真实文章数据
function loadBookData(): Part[] {
  const bookPath = path.join(process.cwd(), 'book')
  const parts: Part[] = []

  for (const partConfig of BOOK_STRUCTURE) {
    const part: Part = {
      id: partConfig.id,
      number: partConfig.number,
      title: partConfig.title,
      subtitle: partConfig.subtitle,
      chapters: []
    }

    for (const chapterConfig of partConfig.chapters) {
      const chapter: Chapter = {
        id: chapterConfig.id,
        title: chapterConfig.title,
        sections: []
      }

      const chapterPath = path.join(bookPath, partConfig.folder, chapterConfig.folder)
      
      try {
        const files = fs.readdirSync(chapterPath)
        const mdFiles = files.filter(f => f.endsWith('.md')).sort()

        for (const file of mdFiles) {
          // 从文件名提取ID和标题
          const match = file.match(/^(\d+\.\d+)\s+(.+)\.md$/)
          if (match) {
            const [, id, title] = match
            const filePath = path.join(chapterPath, file)
            
            chapter.sections.push({
              id,
              title: title.replace(/[:：]/g, ':'), // 统一冒号格式
              isFree: FREE_SECTIONS.includes(id),
              price: 1,
              filePath
            })
          }
        }

        // 按ID数字排序
        chapter.sections.sort((a, b) => {
          const [aMajor, aMinor] = a.id.split('.').map(Number)
          const [bMajor, bMinor] = b.id.split('.').map(Number)
          return aMajor !== bMajor ? aMajor - bMajor : aMinor - bMinor
        })

      } catch (e) {
        console.error(`读取章节目录失败: ${chapterPath}`, e)
      }

      part.chapters.push(chapter)
    }

    parts.push(part)
  }

  return parts
}

// 读取文章内容
function getArticleContent(sectionId: string): string | null {
  const bookData = loadBookData()
  
  for (const part of bookData) {
    for (const chapter of part.chapters) {
      const section = chapter.sections.find(s => s.id === sectionId)
      if (section?.filePath) {
        try {
          return fs.readFileSync(section.filePath, 'utf-8')
        } catch (e) {
          console.error(`读取文章内容失败: ${section.filePath}`, e)
        }
      }
    }
  }
  
  return null
}

// GET - 获取所有章节数据
export async function GET(request: Request) {
  const { searchParams } = new URL(request.url)
  const sectionId = searchParams.get('id')
  const includeContent = searchParams.get('content') === 'true'

  try {
    // 如果指定了章节ID，返回单篇文章内容
    if (sectionId) {
      const content = getArticleContent(sectionId)
      if (content) {
        return NextResponse.json({
          success: true,
          data: { id: sectionId, content }
        })
      } else {
        return NextResponse.json({
          success: false,
          error: '文章不存在'
        }, { status: 404 })
      }
    }

    // 返回完整书籍结构
    const bookData = loadBookData()
    
    // 统计总章节数
    let totalSections = 0
    for (const part of bookData) {
      for (const chapter of part.chapters) {
        totalSections += chapter.sections.length
      }
    }
    // 加上序言、尾声和3个附录
    totalSections += 5

    return NextResponse.json({
      success: true,
      data: {
        totalSections,
        parts: bookData,
        appendix: [
          { id: 'appendix-1', title: '附录1｜Soul派对房精选对话', isFree: true },
          { id: 'appendix-2', title: '附录2｜创业者自检清单', isFree: true },
          { id: 'appendix-3', title: '附录3｜本书提到的工具和资源', isFree: true }
        ],
        preface: { id: 'preface', title: '序言｜为什么我每天早上6点在Soul开播?', isFree: true },
        epilogue: { id: 'epilogue', title: '尾声｜这本书的真实目的', isFree: true }
      }
    })
  } catch (error) {
    console.error('获取章节数据失败:', error)
    return NextResponse.json({
      success: false,
      error: '获取数据失败'
    }, { status: 500 })
  }
}

// POST - 同步章节数据到数据库（预留接口）
export async function POST(request: Request) {
  try {
    const bookData = loadBookData()
    
    // 这里可以添加数据库写入逻辑
    // 目前先返回成功，数据已从文件系统读取
    
    let totalSections = 0
    for (const part of bookData) {
      for (const chapter of part.chapters) {
        totalSections += chapter.sections.length
      }
    }
    totalSections += 5 // 序言、尾声、3个附录

    return NextResponse.json({
      success: true,
      message: '章节数据同步成功',
      data: {
        totalSections,
        partsCount: bookData.length,
        chaptersCount: bookData.reduce((acc, p) => acc + p.chapters.length, 0)
      }
    })
  } catch (error) {
    console.error('同步章节数据失败:', error)
    return NextResponse.json({
      success: false,
      error: '同步数据失败'
    }, { status: 500 })
  }
}