// ── Messages: Single Message ─────────────────────────────────────────────────
// DELETE /api/conversations/[id]/messages/[messageId]
//   — Delete a specific message (soft-delete) owned by the current user.
//   — Handles cleanup of associated voice note audio files.
//
// Auth: authenticated; user must be a participant and the message sender

import { NextRequest, NextResponse } from "next/server"
import { getSessionUser } from "@/lib/auth"
import { query } from "@/lib/db"
import { unlink } from "node:fs/promises"
import { join } from "node:path"
import { existsSync } from "node:fs"

// ── DELETE ───────────────────────────────────────────────────────────────────

export async function DELETE(
  _request: NextRequest,
  { params }: { params: Promise<{ id: string; messageId: string }> },
) {
  try {
    const user = await getSessionUser()
    if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 })

    const { id: conversationId, messageId } = await params

    // Verify user is a participant in this conversation
    const partCheck = await query(
      `SELECT 1 FROM conversation_participants WHERE conversation_id = $1 AND user_id = $2`,
      [conversationId, user.id],
    )
    if (partCheck.rows.length === 0) {
      return NextResponse.json({ error: "Not a participant" }, { status: 403 })
    }

    // Fetch the message to verify it belongs to the sender and check if it's a voice message
    const msgResult = await query(
      `SELECT id, sender_id, content FROM messages WHERE id = $1 AND conversation_id = $2 AND deleted_at IS NULL`,
      [messageId, conversationId],
    )
    if (msgResult.rows.length === 0) {
      return NextResponse.json({ error: "Message not found" }, { status: 404 })
    }

    const message = msgResult.rows[0]

    // Only the sender can delete their own message
    if (message.sender_id !== user.id) {
      return NextResponse.json({ error: "Cannot delete another user's message" }, { status: 403 })
    }

    // Delete the associated audio file if this is a voice message
    let storageDeleted = false
    try {
      const content = message.content
      if (content?.startsWith("{")) {
        const parsed = JSON.parse(content)
        if (parsed.v && parsed.u) {
          const filename = parsed.u.replace(/^\/uploads\/voice\//, "")
          const filePath = join(process.cwd(), "public", "uploads", "voice", filename)
          if (existsSync(filePath)) {
            await unlink(filePath)
            storageDeleted = true
          }
        }
      }
    } catch {
      // If file deletion fails, log but still proceed with DB deletion
      console.warn(`[voice-delete] Failed to delete audio file for message ${messageId}`)
    }

    // Soft-delete the message in the database
    const deleteResult = await query(
      `UPDATE messages SET deleted_at = NOW() WHERE id = $1 AND conversation_id = $2 RETURNING id`,
      [messageId, conversationId],
    )

    const dbDeleted = deleteResult.rows.length > 0

    console.log(
      `[voice-delete] id=${messageId} conv=${conversationId} user=${user.id} db=${dbDeleted} storage=${storageDeleted}`,
    )

    return NextResponse.json({
      success: true,
      messageId,
      dbDeleted,
      storageDeleted,
    })
  } catch (error) {
    console.error("[voice-delete] Error:", error)
    return NextResponse.json({ error: "Unable to delete voice note. Please try again." }, { status: 500 })
  }
}