import { NextRequest, NextResponse } from "next/server";
import { getServerSession } from "next-auth/next";
import { authOptions } from "@/app/api/auth/options";
import { prisma } from "@/lib/prisma";
import { syncInfomaniakCalendar } from "@/lib/services/caldav-sync";
import { syncMicrosoftCalendar } from "@/lib/services/microsoft-calendar-sync";
import { logger } from "@/lib/logger";

/**
 * Create a calendar sync configuration
 * POST /api/calendars/sync
 */
export async function POST(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: "Non authentifié" }, { status: 401 });
    }

    const { calendarId, mailCredentialId, externalCalendarUrl, externalCalendarId, syncFrequency, provider } = await req.json();

    if (!calendarId || !mailCredentialId || !externalCalendarUrl) {
      return NextResponse.json(
        { error: "calendarId, mailCredentialId et externalCalendarUrl sont requis" },
        { status: 400 }
      );
    }

    // Determine provider if not provided
    let detectedProvider = provider;
    if (!detectedProvider) {
      const mailCreds = await prisma.mailCredentials.findUnique({
        where: { id: mailCredentialId },
      });
      if (mailCreds?.host.includes('infomaniak')) {
        detectedProvider = 'infomaniak';
      } else if (mailCreds?.host.includes('outlook.office365.com')) {
        detectedProvider = 'microsoft';
      } else {
        return NextResponse.json(
          { error: "Provider non supporté ou non détecté" },
          { status: 400 }
        );
      }
    }

    // Verify calendar belongs to user
    const calendar = await prisma.calendar.findFirst({
      where: {
        id: calendarId,
        userId: session.user.id,
      },
    });

    if (!calendar) {
      return NextResponse.json(
        { error: "Calendrier non trouvé" },
        { status: 404 }
      );
    }

    // Verify mail credentials belong to user
    const mailCreds = await prisma.mailCredentials.findFirst({
      where: {
        id: mailCredentialId,
        userId: session.user.id,
      },
    });

    if (!mailCreds) {
      return NextResponse.json(
        { error: "Credentials non trouvés" },
        { status: 404 }
      );
    }

    // Create or update sync configuration
    // Use different default frequencies: 5 min for Microsoft (more reactive), 15 min for others
    const defaultSyncFrequency = detectedProvider === 'microsoft' ? 5 : (syncFrequency || 15);
    
    const syncConfig = await prisma.calendarSync.upsert({
      where: { calendarId },
      create: {
        calendarId,
        mailCredentialId,
        provider: detectedProvider,
        externalCalendarId: externalCalendarId || null,
        externalCalendarUrl,
        syncEnabled: true,
        syncFrequency: syncFrequency || defaultSyncFrequency,
      },
      update: {
        mailCredentialId,
        provider: detectedProvider,
        externalCalendarId: externalCalendarId || null,
        externalCalendarUrl,
        syncFrequency: syncFrequency || defaultSyncFrequency,
        syncEnabled: true,
      },
    });

    // Trigger initial sync based on provider
    try {
      if (detectedProvider === 'infomaniak') {
        const { syncInfomaniakCalendar } = await import('@/lib/services/caldav-sync');
        await syncInfomaniakCalendar(syncConfig.id, true);
      } else if (detectedProvider === 'microsoft') {
        const { syncMicrosoftCalendar } = await import('@/lib/services/microsoft-calendar-sync');
        await syncMicrosoftCalendar(syncConfig.id, true);
      }
    } catch (syncError) {
      logger.error('Error during initial sync', {
        syncConfigId: syncConfig.id,
        provider: detectedProvider,
        error: syncError instanceof Error ? syncError.message : String(syncError),
      });
      // Don't fail the request if sync fails, just log it
    }

    return NextResponse.json({ syncConfig });
  } catch (error) {
    logger.error('Error creating calendar sync', {
      error: error instanceof Error ? error.message : String(error),
    });
    return NextResponse.json(
      {
        error: "Erreur lors de la création de la synchronisation",
        details: error instanceof Error ? error.message : String(error),
      },
      { status: 500 }
    );
  }
}

/**
 * Trigger manual sync for a calendar
 * PUT /api/calendars/sync
 */
export async function PUT(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: "Non authentifié" }, { status: 401 });
    }

    const { calendarSyncId } = await req.json();

    if (!calendarSyncId) {
      return NextResponse.json(
        { error: "calendarSyncId est requis" },
        { status: 400 }
      );
    }

    // Verify sync config belongs to user
    const syncConfig = await prisma.calendarSync.findUnique({
      where: { id: calendarSyncId },
      include: {
        calendar: true,
      },
    });

    if (!syncConfig || syncConfig.calendar.userId !== session.user.id) {
      return NextResponse.json(
        { error: "Synchronisation non trouvée" },
        { status: 404 }
      );
    }

    // Trigger sync based on provider
    let result;
    if (syncConfig.provider === 'infomaniak') {
      result = await syncInfomaniakCalendar(calendarSyncId, true);
    } else if (syncConfig.provider === 'microsoft') {
      result = await syncMicrosoftCalendar(calendarSyncId, true);
    } else {
      return NextResponse.json(
        { error: "Provider non supporté" },
        { status: 400 }
      );
    }

    return NextResponse.json({ success: true, result });
  } catch (error) {
    logger.error('Error triggering calendar sync', {
      error: error instanceof Error ? error.message : String(error),
    });
    return NextResponse.json(
      {
        error: "Erreur lors de la synchronisation",
        details: error instanceof Error ? error.message : String(error),
      },
      { status: 500 }
    );
  }
}

/**
 * Get sync status for user calendars
 * GET /api/calendars/sync
 */
export async function GET(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: "Non authentifié" }, { status: 401 });
    }

    const syncConfigs = await prisma.calendarSync.findMany({
      where: {
        calendar: {
          userId: session.user.id,
        },
      },
      include: {
        calendar: true,
        mailCredential: {
          select: {
            id: true,
            email: true,
            display_name: true,
          },
        },
      },
    });

    return NextResponse.json({ syncConfigs });
  } catch (error) {
    logger.error('Error fetching sync configs', {
      error: error instanceof Error ? error.message : String(error),
    });
    return NextResponse.json(
      { error: "Erreur serveur" },
      { status: 500 }
    );
  }
}

/**
 * Delete sync configuration
 * DELETE /api/calendars/sync
 */
export async function DELETE(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: "Non authentifié" }, { status: 401 });
    }

    const { calendarSyncId } = await req.json();

    if (!calendarSyncId) {
      return NextResponse.json(
        { error: "calendarSyncId est requis" },
        { status: 400 }
      );
    }

    // Verify sync config belongs to user
    const syncConfig = await prisma.calendarSync.findUnique({
      where: { id: calendarSyncId },
      include: {
        calendar: true,
      },
    });

    if (!syncConfig || syncConfig.calendar.userId !== session.user.id) {
      return NextResponse.json(
        { error: "Synchronisation non trouvée" },
        { status: 404 }
      );
    }

    await prisma.calendarSync.delete({
      where: { id: calendarSyncId },
    });

    return NextResponse.json({ success: true });
  } catch (error) {
    logger.error('Error deleting sync config', {
      error: error instanceof Error ? error.message : String(error),
    });
    return NextResponse.json(
      { error: "Erreur serveur" },
      { status: 500 }
    );
  }
}