import { prisma } from '@/lib/prisma'
import { getAIProvider } from '@/lib/ai/factory'

export interface NoteForOrganization {
  id: string
  title: string | null
  content: string
}

export interface NotebookOrganization {
  notebookId: string
  notebookName: string
  notebookIcon: string | null
  notebookColor: string | null
  notes: Array<{
    noteId: string
    title: string | null
    content: string
    confidence: number
    reason: string
  }>
}

export interface OrganizationPlan {
  notebooks: NotebookOrganization[]
  totalNotes: number
  unorganizedNotes: number // Notes that couldn't be categorized
}

/**
 * Service for batch organizing notes from "Notes générales" into notebooks
 * (Story 5.3 - IA3)
 */
export class BatchOrganizationService {
  /**
   * Analyze all notes in "Notes générales" and create an organization plan
   * @param userId - User ID
   * @returns Organization plan with notebook assignments
   */
  async createOrganizationPlan(userId: string): Promise<OrganizationPlan> {
    // 1. Get all notes without notebook (Inbox/Notes générales)
    const notesWithoutNotebook = await prisma.note.findMany({
      where: {
        userId,
        notebookId: null,
      },
      select: {
        id: true,
        title: true,
        content: true,
      },
      orderBy: {
        updatedAt: 'desc',
      },
      take: 50, // Limit to 50 notes for AI processing
    })

    if (notesWithoutNotebook.length === 0) {
      return {
        notebooks: [],
        totalNotes: 0,
        unorganizedNotes: 0,
      }
    }

    // 2. Get all user's notebooks
    const notebooks = await prisma.notebook.findMany({
      where: { userId },
      include: {
        labels: true,
        _count: {
          select: { notes: true },
        },
      },
      orderBy: { order: 'asc' },
    })

    if (notebooks.length === 0) {
      // No notebooks to organize into
      return {
        notebooks: [],
        totalNotes: notesWithoutNotebook.length,
        unorganizedNotes: notesWithoutNotebook.length,
      }
    }

    // 3. Call AI to create organization plan
    const plan = await this.aiOrganizeNotes(notesWithoutNotebook, notebooks)

    return plan
  }

  /**
   * Use AI to analyze notes and create organization plan
   */
  private async aiOrganizeNotes(
    notes: NoteForOrganization[],
    notebooks: any[]
  ): Promise<OrganizationPlan> {
    const prompt = this.buildPrompt(notes, notebooks)

    try {
      const provider = getAIProvider()
      const response = await provider.generateText(prompt)

      // Parse AI response
      const plan = this.parseAIResponse(response, notes, notebooks)

      return plan
    } catch (error) {
      console.error('Failed to create organization plan:', error)
      // Return empty plan on error
      return {
        notebooks: [],
        totalNotes: notes.length,
        unorganizedNotes: notes.length,
      }
    }
  }

  /**
   * Build prompt for AI (always in French - interface language)
   */
  private buildPrompt(notes: NoteForOrganization[], notebooks: any[]): string {
    const notebookList = notebooks
      .map(nb => {
        const labels = nb.labels.map((l: any) => l.name).join(', ')
        const count = nb._count?.notes || 0
        return `- ${nb.name} (${count} notes)${labels ? ` [labels: ${labels}]` : ''}`
      })
      .join('\n')

    const notesList = notes
      .map((note, index) => {
        const title = note.title || 'Sans titre'
        const content = note.content.substring(0, 200)
        return `[${index}] "${title}": ${content}`
      })
      .join('\n')

    return `
Tu es un assistant qui organise des notes en les regroupant par thématique dans des carnets.

CARNETS DISPONIBLES :
${notebookList}

NOTES À ORGANISER (Notes générales) :
${notesList}

TÂCHE :
Analyse chaque note et propose le carnet le PLUS approprié.
Considère :
1. Le sujet/thème de la note (LE PLUS IMPORTANT)
2. Les labels existants dans chaque carnet
3. La cohérence thématique entre notes du même carnet

GUIDES DE CLASSIFICATION :
- SPORT/EXERCICE/ACHATS/COURSSES → Carnet Personnel
- LOISIRS/PASSIONS/SORTIES → Carnet Personnel
- SANTÉ/FITNESS/MÉDECIN → Carnet Personnel ou Santé
- FAMILLE/AMIS → Carnet Personnel
- TRAVAIL/RÉUNIONS/PROJETS/CLIENTS → Carnet Travail
- CODING/TECH/DÉVELOPPEMENT → Carnet Travail ou Code
- FINANCES/FACTURES/BANQUE → Carnet Personnel ou Finances

FORMAT DE RÉPONSE (JSON) :
Pour chaque carnet, liste les notes qui lui appartiennent :
{
  "carnets": [
    {
      "nom": "Nom du carnet",
      "notes": [
        {
          "index": 0,
          "confiance": 0.95,
          "raison": "Courte explication"
        }
      ]
    }
  ]
}

RÈGLES :
- Seules les notes avec confiance > 0.60 doivent être assignées
- Si une note est trop générique, ne l'assigne pas
- Sois précis dans tes regroupements thématiques

Ta réponse (JSON seulement) :
`.trim()
  }

  /**
   * Parse AI response into OrganizationPlan
   */
  private parseAIResponse(
    response: string,
    notes: NoteForOrganization[],
    notebooks: any[]
  ): OrganizationPlan {
    try {
      // Try to parse JSON response
      const jsonMatch = response.match(/\{[\s\S]*\}/)
      if (!jsonMatch) {
        throw new Error('No JSON found in response')
      }

      const aiData = JSON.parse(jsonMatch[0])

      const notebookOrganizations: NotebookOrganization[] = []

      // Process each notebook in AI response
      for (const aiNotebook of aiData.carnets || []) {
        const notebook = notebooks.find(nb => nb.name === aiNotebook.nom)
        if (!notebook) continue

        const noteAssignments = aiNotebook.notes
          .filter((n: any) => n.confiance > 0.60) // Only high confidence
          .map((n: any) => {
            const note = notes[n.index]
            if (!note) return null

            return {
              noteId: note.id,
              title: note.title,
              content: note.content,
              confidence: n.confiance,
              reason: n.raison || '',
            }
          })
          .filter(Boolean)

        if (noteAssignments.length > 0) {
          notebookOrganizations.push({
            notebookId: notebook.id,
            notebookName: notebook.name,
            notebookIcon: notebook.icon,
            notebookColor: notebook.color,
            notes: noteAssignments,
          })
        }
      }

      // Count unorganized notes
      const organizedNoteIds = new Set(
        notebookOrganizations.flatMap(nb => nb.notes.map(n => n.noteId))
      )
      const unorganizedCount = notes.length - organizedNoteIds.size

      return {
        notebooks: notebookOrganizations,
        totalNotes: notes.length,
        unorganizedNotes: unorganizedCount,
      }
    } catch (error) {
      console.error('Failed to parse AI response:', error)
      return {
        notebooks: [],
        totalNotes: notes.length,
        unorganizedNotes: notes.length,
      }
    }
  }

  /**
   * Apply the organization plan (move notes to notebooks)
   * @param userId - User ID
   * @param plan - Organization plan to apply
   * @param selectedNoteIds - Specific note IDs to organize (user can deselect)
   * @returns Number of notes moved
   */
  async applyOrganizationPlan(
    userId: string,
    plan: OrganizationPlan,
    selectedNoteIds: string[]
  ): Promise<number> {
    let movedCount = 0

    for (const notebookOrg of plan.notebooks) {
      // Filter notes that are selected
      const notesToMove = notebookOrg.notes.filter(n =>
        selectedNoteIds.includes(n.noteId)
      )

      if (notesToMove.length === 0) continue

      // Move notes to notebook
      await prisma.note.updateMany({
        where: {
          id: { in: notesToMove.map(n => n.noteId) },
          userId,
        },
        data: {
          notebookId: notebookOrg.notebookId,
        },
      })

      movedCount += notesToMove.length
    }

    return movedCount
  }
}

// Export singleton instance
export const batchOrganizationService = new BatchOrganizationService()