import { getChatProvider } from '../factory'
import { getSystemConfig } from '@/lib/config'
import { preprocessMathInHtml } from '@/lib/text/math-preprocess'

export interface GeneratedNote {
  title: string
  content: string
  difficulty?: 'facile' | 'moyen' | 'difficile'
}

export interface GeneratedCarnet {
  /** Short notebook title (not the raw user prompt). */
  notebookName?: string
  notes: GeneratedNote[]
  schemaProperties: Array<{ name: string; type: string; options?: string[] }>
}

export type WizardProfile = 'student' | 'teacher' | 'engineer'

/** Word-count targets by level — Expert was failing (timeouts / truncated JSON). */
function wordTargetsForLevel(level?: string): { min: number; max: number; label: string } {
  const l = (level || '').toLowerCase()
  if (/expert|avancé|advanced|fort/.test(l)) {
    return { min: 350, max: 700, label: 'expert (350–700 mots/note — dense mais JSON-fiable)' }
  }
  if (/intermédiaire|intermediate|moyen/.test(l)) {
    return { min: 250, max: 500, label: 'intermédiaire (250–500 mots/note)' }
  }
  if (/débutant|beginner|facile|easy/.test(l)) {
    return { min: 150, max: 350, label: 'débutant (150–350 mots/note)' }
  }
  return { min: 200, max: 450, label: 'standard (200–450 mots/note)' }
}

export class NotebookWizardService {
  async generateCarnet(
    profile: WizardProfile,
    topic: string,
    options?: { level?: string; count?: number; language?: string }
  ): Promise<GeneratedCarnet> {
    const lang = options?.language || 'fr'
    // Cap count in expert mode to avoid oversized responses
    const level = options?.level
    const isExpert = /expert/i.test(level || '')
    const count = Math.min(options?.count || 6, isExpert ? 5 : 10)

    const prompts = this.buildPrompt(profile, topic, lang, count, level)
    const config = await getSystemConfig()
    const provider = getChatProvider(config)
    let raw: string
    try {
      raw = await provider.generateText(prompts)
    } catch (err) {
      // Retry once with lighter prompt if expert/full generation fails
      if (isExpert) {
        const light = this.buildPrompt(profile, topic, lang, Math.min(count, 4), 'Avancé')
        raw = await provider.generateText(light)
      } else {
        throw err
      }
    }

    const result = this.parseResponse(raw, profile, lang)
    if (!result.notebookName?.trim()) {
      result.notebookName = this.deriveNotebookName(topic, result.notes, lang)
    }
    return result
  }

  /** Fallback short name when the model omits notebookName. */
  private deriveNotebookName(topic: string, notes: GeneratedNote[], lang: string): string {
    const fromNote = notes[0]?.title?.trim()
    if (fromNote && fromNote.length <= 80 && fromNote.length >= 3) {
      // Prefer first chapter title cleaned of numbering
      return fromNote.replace(/^\d+[\.\):\-–]\s*/, '').slice(0, 80)
    }
    const cleaned = topic
      .replace(/\s+/g, ' ')
      .trim()
      .replace(/^(je veux|i want|please|peux-tu|can you|crée|create|génère|generate)\b[\s,:-]*/i, '')
    if (cleaned.length > 0 && cleaned.length <= 60) return cleaned
    if (cleaned.length > 60) {
      const cut = cleaned.slice(0, 57)
      const lastSpace = cut.lastIndexOf(' ')
      return (lastSpace > 20 ? cut.slice(0, lastSpace) : cut) + '…'
    }
    return lang === 'fr' ? 'Nouveau carnet' : 'New notebook'
  }

  private buildPrompt(
    profile: WizardProfile,
    topic: string,
    lang: string,
    count: number,
    level?: string
  ): string {
    const langName = lang === 'fr' ? 'français' : lang === 'en' ? 'English' : lang === 'fa' ? 'فارسی' : lang === 'ar' ? 'العربية' : lang === 'de' ? 'Deutsch' : lang === 'es' ? 'Español' : lang === 'it' ? 'Italiano' : lang === 'pt' ? 'Português' : lang === 'ru' ? 'Русский' : lang === 'zh' ? '中文' : lang === 'ja' ? '日本語' : lang === 'ko' ? '한국어' : lang === 'nl' ? 'Nederlands' : lang === 'pl' ? 'Polski' : lang === 'hi' ? 'हिन्दी' : lang

    const words = wordTargetsForLevel(level)
    const schemaLabels = this.getSchemaLabels(lang)
    const profileContext = {
      student: `Tu crées des notes de cours pour un étudiant. Le contenu doit être pédagogique, clair, avec des exemples.`,
      teacher: `Tu crées la structure d'un cours pour un professeur. Chaque note est un chapitre avec des sections à remplir, des objectifs, et des exercices.`,
      engineer: `Tu crées une documentation technique. Le contenu doit être précis, structuré, avec des spécifications et des références.`,
    }[profile]

    return `Tu es un expert pédagogue et créateur de contenu de haut niveau. ${profileContext}

Sujet (intention de l'utilisateur, NE PAS recopier tel quel comme titre de carnet) : "${topic}"
${level ? `Niveau : ${level}` : ''}
Langue : ${langName}
Nombre de notes à créer : ${count}
Profondeur cible : ${words.label}

CRÉE ${count} NOTES COMPLÈTES sur ce sujet. Chaque note : environ ${words.min}–${words.max} mots (qualité > longueur extrême).

IMPORTANT — NOM DU CARNET :
- Fournis "notebookName" : un titre COURT et PERTINENT (3–8 mots, max 60 caractères).
- Exemple : pour un long message sur la thermo HVAC → "Modélisation thermodynamique HVAC"
- N'utilise JAMAIS la phrase complète de l'utilisateur comme nom.

Le contenu doit être :
- Clair et structuré avec <h2> et <h3>
- Des exemples concrets
- Des définitions dans des callouts
${profile === 'student' ? '- Points clés en callout tip\n- Pièges à éviter en callout danger' : ''}
${profile === 'teacher' ? '- Objectifs pédagogiques\n- Section Exercices (3–5 questions)' : ''}
${profile === 'engineer' ? '- Spécifications techniques\n- Tableaux comparatifs si utile' : ''}

FORMAT DE SORTIE — JSON UNIQUEMENT (pas de markdown hors du bloc) :
\`\`\`json
{
  "notebookName": "Titre court du carnet",
  "notes": [
    {
      "title": "Titre de chapitre descriptif",
      "difficulty": "facile",
      "content": "<h2>Introduction</h2><p>...</p>..."
    }
  ],
  "schemaProperties": [
    { "name": "${schemaLabels.status}", "type": "select", "options": ["${schemaLabels.statusTodo}", "${schemaLabels.statusInProgress}", "${schemaLabels.statusDone}"] },
    { "name": "${schemaLabels.difficulty}", "type": "select", "options": ["${schemaLabels.easy}", "${schemaLabels.medium}", "${schemaLabels.hard}"] }
  ]
}
\`\`\`

BLOCS HTML DISPONIBLES :

1. Callout : <div data-type="callout-block" data-callout-type="info"><p>...</p></div> (info|warning|tip|success|danger)
2. Toggle : <div data-type="toggle-block" data-opened="true"><p>Titre</p><p>Contenu</p></div>
3. Math : <div data-type="math-equation" data-latex="E = mc^2"></div> — JAMAIS $$ 
4. Colonnes : <div data-type="columns" cols="2">...</div>
5. Sommaire : <div data-type="outline-block"></div>
6. HTML : <h2>/<h3>, <p>, <ul>/<ol>/<li>, <table>, <blockquote>, <pre><code>

Les "difficulty" doivent varier : facile/moyen/difficile.
Réponds UNIQUEMENT avec le JSON valide (échappement correct des guillemets dans le HTML).`
  }

  private getSchemaLabels(lang: string) {
    const map: Record<string, { status: string; statusTodo: string; statusInProgress: string; statusDone: string; difficulty: string; easy: string; medium: string; hard: string }> = {
      fr: { status: 'Statut', statusTodo: 'À réviser', statusInProgress: 'En cours', statusDone: 'Maîtrisé', difficulty: 'Difficulté', easy: 'Facile', medium: 'Moyen', hard: 'Difficile' },
      en: { status: 'Status', statusTodo: 'To review', statusInProgress: 'In progress', statusDone: 'Mastered', difficulty: 'Difficulty', easy: 'Easy', medium: 'Medium', hard: 'Hard' },
      fa: { status: 'وضعیت', statusTodo: 'باید مرور شود', statusInProgress: 'در حال یادگیری', statusDone: 'تسلط یافته', difficulty: 'سختی', easy: 'آسان', medium: 'متوسط', hard: 'دشوار' },
      ar: { status: 'الحالة', statusTodo: 'للمراجعة', statusInProgress: 'قيد الدراسة', statusDone: 'متقن', difficulty: 'الصعوبة', easy: 'سهل', medium: 'متوسط', hard: 'صعب' },
      de: { status: 'Status', statusTodo: 'Zu wiederholen', statusInProgress: 'In Bearbeitung', statusDone: 'Beherrscht', difficulty: 'Schwierigkeit', easy: 'Einfach', medium: 'Mittel', hard: 'Schwer' },
      es: { status: 'Estado', statusTodo: 'Por repasar', statusInProgress: 'En progreso', statusDone: 'Dominado', difficulty: 'Dificultad', easy: 'Fácil', medium: 'Medio', hard: 'Difícil' },
      it: { status: 'Stato', statusTodo: 'Da ripassare', statusInProgress: 'In corso', statusDone: 'Padroneggiato', difficulty: 'Difficoltà', easy: 'Facile', medium: 'Medio', hard: 'Difficile' },
      pt: { status: 'Estado', statusTodo: 'A rever', statusInProgress: 'Em progresso', statusDone: 'Dominado', difficulty: 'Dificuldade', easy: 'Fácil', medium: 'Médio', hard: 'Difícil' },
      ru: { status: 'Статус', statusTodo: 'На повторение', statusInProgress: 'В процессе', statusDone: 'Усвоено', difficulty: 'Сложность', easy: 'Лёгкий', medium: 'Средний', hard: 'Сложный' },
      zh: { status: '状态', statusTodo: '待复习', statusInProgress: '学习中', statusDone: '已掌握', difficulty: '难度', easy: '简单', medium: '中等', hard: '困难' },
      ja: { status: 'ステータス', statusTodo: '要復習', statusInProgress: '学習中', statusDone: '習得済み', difficulty: '難易度', easy: '易しい', medium: '普通', hard: '難しい' },
      ko: { status: '상태', statusTodo: '복습 필요', statusInProgress: '학습 중', statusDone: '마스터', difficulty: '난이도', easy: '쉬움', medium: '보통', hard: '어려움' },
      nl: { status: 'Status', statusTodo: 'Te herhalen', statusInProgress: 'Bezig', statusDone: 'Beheerst', difficulty: 'Moeilijkheid', easy: 'Makkelijk', medium: 'Gemiddeld', hard: 'Moeilijk' },
      pl: { status: 'Status', statusTodo: 'Do powtórki', statusInProgress: 'W trakcie', statusDone: 'Opanowane', difficulty: 'Trudność', easy: 'Łatwy', medium: 'Średni', hard: 'Trudny' },
      hi: { status: 'स्थिति', statusTodo: 'दोहराने के लिए', statusInProgress: 'प्रगति में', statusDone: 'महारत हासिल', difficulty: 'कठिनाई', easy: 'आसान', medium: 'मध्यम', hard: 'कठिन' },
    }
    return map[lang] || map.en
  }

  private parseResponse(raw: string, profile: WizardProfile, lang?: string): GeneratedCarnet {
    const jsonMatch = raw.match(/```json\s*([\s\S]+?)\s*```/)
    let jsonStr = jsonMatch ? jsonMatch[1] : raw

    // Extract the JSON object boundaries
    const start = jsonStr.indexOf('{')
    const end = jsonStr.lastIndexOf('}')
    if (start >= 0 && end > start) {
      jsonStr = jsonStr.slice(start, end + 1)
    }

    let parsed: any
    try {
      parsed = JSON.parse(jsonStr)
    } catch {
      // Fix common AI JSON issues: unescaped backslashes in LaTeX
      try {
        const fixed = jsonStr
          .replace(/\\(?!["\\\/bfnrtu])/g, '\\\\')  // Escape lone backslashes (LaTeX \frac etc.)
          .replace(/\n/g, '\\n')  // Fix raw newlines in strings
        parsed = JSON.parse(fixed)
      } catch {
        try {
          // Last resort: extract notes manually with regex
          const notes: GeneratedNote[] = []
          const titleMatches = [...jsonStr.matchAll(/"title"\s*:\s*"([^"]+)"/g)]
          const contentMatches = [...jsonStr.matchAll(/"content"\s*:\s*"([\s\S]*?)"(?:,|\s*})/g)]
          for (let i = 0; i < titleMatches.length; i++) {
            notes.push({
              title: titleMatches[i][1],
              content: contentMatches[i]?.[1]?.replace(/\\n/g, '\n').replace(/\\"/g, '"') || '<p></p>',
              difficulty: i % 3 === 0 ? 'facile' : i % 3 === 1 ? 'moyen' : 'difficile',
            })
          }
          if (notes.length === 0) throw new Error('No notes found in response')
          const fallbackLabels = this.getSchemaLabels(lang || 'fr')
          return {
            notes,
            schemaProperties: [
              { name: fallbackLabels.status, type: 'select', options: [fallbackLabels.statusTodo, fallbackLabels.statusInProgress, fallbackLabels.statusDone] },
              { name: fallbackLabels.difficulty, type: 'select', options: [fallbackLabels.easy, fallbackLabels.medium, fallbackLabels.hard] },
            ],
          }
        } catch {
          throw new Error('Failed to parse AI response')
        }
      }
    }

    const notes: GeneratedNote[] = (parsed.notes || []).map((n: any) => ({
      title: String(n.title || 'Sans titre'),
      content: preprocessMathInHtml(String(n.content || '<p></p>')),
      difficulty: n.difficulty || undefined,
    }))

    const defaultLabels = this.getSchemaLabels(lang || 'fr')
    const schemaProperties = parsed.schemaProperties || [
      { name: defaultLabels.status, type: 'select', options: [defaultLabels.statusTodo, defaultLabels.statusInProgress, defaultLabels.statusDone] },
      { name: defaultLabels.difficulty, type: 'select', options: [defaultLabels.easy, defaultLabels.medium, defaultLabels.hard] },
    ]

    const notebookName = typeof parsed.notebookName === 'string'
      ? parsed.notebookName.trim().slice(0, 80)
      : undefined

    return { notebookName, notes, schemaProperties }
  }
}

export const notebookWizardService = new NotebookWizardService()