import { getServerSession } from "next-auth/next";
import { authOptions } from "@/app/api/auth/options";
import { NextResponse } from "next/server";
import { prisma } from "@/lib/prisma";
import { logger } from "@/lib/logger";

async function getAdminToken() {
  try {
    const tokenResponse = await fetch(
      `${process.env.KEYCLOAK_BASE_URL}/realms/${process.env.KEYCLOAK_REALM}/protocol/openid-connect/token`,
      {
        method: 'POST',
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
        },
        body: new URLSearchParams({
          grant_type: 'client_credentials',
          client_id: process.env.KEYCLOAK_CLIENT_ID!,
          client_secret: process.env.KEYCLOAK_CLIENT_SECRET!,
        }),
      }
    );

    const data = await tokenResponse.json();
    if (!tokenResponse.ok || !data.access_token) {
      logger.error('Token Error', { error: data });
      return null;
    }

    return data.access_token;
  } catch (error) {
    logger.error('Token Error', {
      error: error instanceof Error ? error.message : String(error)
    });
    return null;
  }
}

/**
 * PATCH /api/groups/[groupId]/calendar
 * Updates the color of a group's calendar
 */
export async function PATCH(
  req: Request,
  props: { params: Promise<{ groupId: string }> }
) {
  const params = await props.params;
  
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: "Non autorisé" }, { status: 401 });
    }

    const { color } = await req.json();
    
    if (!color) {
      return NextResponse.json(
        { error: "La couleur est requise" },
        { status: 400 }
      );
    }

    // Validate color format (hex color)
    const hexColorRegex = /^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$/;
    if (!hexColorRegex.test(color)) {
      return NextResponse.json(
        { error: "Format de couleur invalide. Utilisez un code hexadécimal (ex: #FF5733)" },
        { status: 400 }
      );
    }

    const token = await getAdminToken();
    if (!token) {
      return NextResponse.json(
        { error: "Erreur d'authentification" },
        { status: 500 }
      );
    }

    // Get group details from Keycloak
    const groupResponse = await fetch(
      `${process.env.KEYCLOAK_BASE_URL}/admin/realms/${process.env.KEYCLOAK_REALM}/groups/${params.groupId}`,
      {
        headers: {
          Authorization: `Bearer ${token}`,
        },
      }
    );

    if (!groupResponse.ok) {
      logger.error('Group not found', { groupId: params.groupId });
      return NextResponse.json(
        { error: "Groupe non trouvé" },
        { status: 404 }
      );
    }

    const group = await groupResponse.json();

    // Check if user is a member of the group
    const membersResponse = await fetch(
      `${process.env.KEYCLOAK_BASE_URL}/admin/realms/${process.env.KEYCLOAK_REALM}/groups/${params.groupId}/members`,
      {
        headers: {
          Authorization: `Bearer ${token}`,
        },
      }
    );

    if (membersResponse.ok) {
      const members = await membersResponse.json();
      const isMember = members.some((member: any) => member.id === session.user.id);
      
      if (!isMember) {
        logger.warn('User not a member of group', {
          userId: session.user.id,
          groupId: params.groupId
        });
        return NextResponse.json(
          { error: "Vous devez être membre du groupe pour modifier sa couleur" },
          { status: 403 }
        );
      }
    }

    // Find the group's calendar
    const calendar = await prisma.calendar.findFirst({
      where: {
        name: `Groupe: ${group.name}`,
      },
    });

    if (!calendar) {
      logger.error('Calendar not found for group', {
        groupId: params.groupId,
        groupName: group.name
      });
      return NextResponse.json(
        { error: "Calendrier du groupe non trouvé" },
        { status: 404 }
      );
    }

    // Update calendar color
    const updatedCalendar = await prisma.calendar.update({
      where: {
        id: calendar.id,
      },
      data: {
        color: color,
      },
    });

    logger.debug('Group calendar color updated', {
      groupId: params.groupId,
      calendarId: calendar.id,
      newColor: color,
      userId: session.user.id
    });

    return NextResponse.json({
      success: true,
      calendar: updatedCalendar,
    });
  } catch (error) {
    logger.error('Error updating group calendar color', {
      groupId: params.groupId,
      error: error instanceof Error ? error.message : String(error)
    });
    return NextResponse.json(
      { error: "Erreur lors de la mise à jour de la couleur" },
      { status: 500 }
    );
  }
}

/**
 * GET /api/groups/[groupId]/calendar
 * Gets the calendar associated with a group
 */
export async function GET(
  req: Request,
  props: { params: Promise<{ groupId: string }> }
) {
  const params = await props.params;
  
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: "Non autorisé" }, { status: 401 });
    }

    const token = await getAdminToken();
    if (!token) {
      return NextResponse.json(
        { error: "Erreur d'authentification" },
        { status: 500 }
      );
    }

    // Get group details from Keycloak
    const groupResponse = await fetch(
      `${process.env.KEYCLOAK_BASE_URL}/admin/realms/${process.env.KEYCLOAK_REALM}/groups/${params.groupId}`,
      {
        headers: {
          Authorization: `Bearer ${token}`,
        },
      }
    );

    if (!groupResponse.ok) {
      return NextResponse.json(
        { error: "Groupe non trouvé" },
        { status: 404 }
      );
    }

    const group = await groupResponse.json();

    // Find the group's calendar
    const calendar = await prisma.calendar.findFirst({
      where: {
        name: `Groupe: ${group.name}`,
      },
    });

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

    return NextResponse.json(calendar);
  } catch (error) {
    logger.error('Error getting group calendar', {
      groupId: params.groupId,
      error: error instanceof Error ? error.message : String(error)
    });
    return NextResponse.json(
      { error: "Erreur lors de la récupération du calendrier" },
      { status: 500 }
    );
  }
}