import { NextRequest, NextResponse } from 'next/server'
import prisma from '@/lib/prisma'
import { auth } from '@/auth'
import { verifyParticipant } from '@/lib/brainstorm-collab'

export async function POST(
  request: NextRequest,
  { params }: { params: Promise<{ sessionId: string }> }
) {
  const session = await auth()
  if (!session?.user?.id) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
  }

  try {
    const { sessionId } = await params

    const brainstormSession = await prisma.brainstormSession.findFirst({
      where: {
        id: sessionId,
        OR: [
          { userId: session.user.id },
          { participants: { some: { userId: session.user.id } } },
        ],
      },
      include: {
        ideas: {
          orderBy: [{ waveNumber: 'asc' }, { createdAt: 'asc' }],
          include: {
            noteRefs: {
              include: {
                note: { select: { id: true, title: true } },
              },
            },
          },
        },
      },
    })

    if (!brainstormSession) {
      return NextResponse.json({ error: 'Session not found' }, { status: 404 })
    }

    if (brainstormSession.exportedNoteId) {
      const existingNote = await prisma.note.findUnique({
        where: { id: brainstormSession.exportedNoteId },
      })
      if (existingNote) {
        return NextResponse.json({ success: true, data: existingNote })
      }
    }

    const waveLabels: Record<number, string> = {
      1: '🔄 Variations',
      2: '🔗 Analogies',
      3: '💥 Disruptions',
    }

    const activeIdeas = brainstormSession.ideas.filter(i => i.status !== 'dismissed')
    const convertedIdeas = brainstormSession.ideas.filter(i => i.status === 'converted')
    const dismissedCount = brainstormSession.ideas.filter(i => i.status === 'dismissed').length

    let markdown = `# Brainstorm: ${brainstormSession.seedIdea}\n\n`
    markdown += `> Generated on ${brainstormSession.createdAt.toLocaleDateString()}\n\n`
    markdown += `---\n\n`
    markdown += `**Summary**: ${activeIdeas.length} active ideas, ${convertedIdeas.length} converted to notes, ${dismissedCount} dismissed.\n\n`

    for (let wave = 1; wave <= 3; wave++) {
      const waveIdeas = activeIdeas.filter(i => i.waveNumber === wave)
      if (waveIdeas.length === 0) continue

      markdown += `## ${waveLabels[wave] || `Wave ${wave}`}\n\n`
      for (const idea of waveIdeas) {
        const statusIcon = idea.status === 'converted' ? '✅' : idea.status === 'dismissed' ? '❌' : '💡'
        markdown += `### ${statusIcon} ${idea.title}\n`
        markdown += `${idea.description}\n\n`
        markdown += `- **Connection**: ${idea.connectionToSeed || 'N/A'}\n`
        markdown += `- **Novelty**: ${idea.noveltyScore || 'N/A'}/10\n`

        const validRefs = (idea.noteRefs || []).filter(r => r.noteId && r.note)
        if (validRefs.length > 0) {
          markdown += `- **Origin**:\n`
          for (const ref of validRefs) {
            const relLabel = {
              derived_from: 'Derived from',
              opposes: 'Opposes',
              extends: 'Extends',
              synthesizes: 'Synthesizes',
              transposes: 'Transposes',
            }[ref.relation] || 'Related to'
            markdown += `  - ${relLabel} [${ref.note?.title || 'Untitled'}](note:${ref.noteId}): ${ref.explanation}\n`
          }
        }

        if (idea.convertedToNoteId) {
          markdown += `- **→ Converted to note**: ${idea.convertedToNoteId}\n`
        }
        if (idea.parentIdeaId) {
          const parent = brainstormSession.ideas.find(i => i.id === idea.parentIdeaId)
          if (parent) {
            markdown += `- **Parent idea**: ${parent.title}\n`
          }
        }
        markdown += `\n`
      }
    }

    const allReferencedNoteIds = new Set<string>()
    for (const idea of brainstormSession.ideas) {
      for (const ref of idea.noteRefs || []) {
        if (ref.noteId) allReferencedNoteIds.add(ref.noteId)
      }
    }

    if (allReferencedNoteIds.size > 0) {
      markdown += `---\n\n## Notes sollicitées\n\n`
      const refNotes = await prisma.note.findMany({
        where: { id: { in: Array.from(allReferencedNoteIds) } },
        select: { id: true, title: true },
      })
      for (const note of refNotes) {
        const refsForNote = brainstormSession.ideas.flatMap(i =>
          (i.noteRefs || []).filter(r => r.noteId === note.id)
        )
        const accepted = refsForNote.filter(r => r.verdict === 'accepted').length
        const dismissed = refsForNote.filter(r => r.verdict === 'dismissed').length
        const verdictStr = accepted > 0 ? `✅ ${accepted} idea(s) accepted` : dismissed > 0 ? `❌ all dismissed` : '⏳ unresolved'
        markdown += `- [${note.title || 'Untitled'}](note:${note.id}) — ${verdictStr}\n`
      }
      markdown += `\n`
    }

    if (convertedIdeas.length > 0) {
      markdown += `## Converted Notes\n\n`
      const convertedNoteIds = convertedIdeas
        .map(i => i.convertedToNoteId)
        .filter(Boolean) as string[]

      if (convertedNoteIds.length > 0) {
        const notes = await prisma.note.findMany({
          where: { id: { in: convertedNoteIds } },
          select: { id: true, title: true },
        })
        for (const note of notes) {
          markdown += `- [${note.title || 'Untitled'}](note:${note.id})\n`
        }
      }
    }

    const notebookName = brainstormSession.seedIdea.length > 40
      ? brainstormSession.seedIdea.substring(0, 40).trim() + '…'
      : brainstormSession.seedIdea

    let notebook = await prisma.notebook.findFirst({
      where: { userId: session.user.id, name: notebookName, trashedAt: null },
    })

    if (!notebook) {
      const notebookCount = await prisma.notebook.count({ where: { userId: session.user.id, trashedAt: null } })
      notebook = await prisma.notebook.create({
        data: {
          userId: session.user.id,
          name: notebookName,
          order: notebookCount,
          icon: 'wind',
        },
      })
    }

    const note = await prisma.note.create({
      data: {
        userId: session.user.id,
        title: `Synthèse: ${brainstormSession.seedIdea.slice(0, 50)}`,
        content: markdown,
        type: 'markdown',
        labels: JSON.stringify(['brainstorm', 'export']),
        notebookId: notebook.id,
      },
    })

    await prisma.brainstormSession.update({
      where: { id: sessionId },
      data: { exportedNoteId: note.id },
    })

    return NextResponse.json({ success: true, data: { ...note, _notebookName: notebookName } }, { status: 201 })
  } catch (error) {
    console.error('Error exporting brainstorm:', error)
    return NextResponse.json(
      { error: 'Failed to export brainstorm' },
      { status: 500 }
    )
  }
}