const db = require("../db");
const { reportError } = require("../lib/report-error");

// Weekly schedule repository methods (PostgreSQL mode; no DEV_MOCK branch in
// the original handlers, so this module is used in both modes).

async function updateWeeklyScheduleStatus(req) {
  try {
    const scheduleId = Number(req.params.scheduleId);
    const { status } = req.body;
    const validStatuses = [
      "planned",
      "in_progress",
      "completed",
      "cancelled",
      "active",
    ];
    if (!Number.isInteger(scheduleId) || !validStatuses.includes(status)) {
      return { statusCode: 400, body: { error: "invalid_status" } };
    }

    const normalizedStatus = status === "active" ? "in_progress" : status;
    const result = await db.query(
      `
      UPDATE schedules s
      SET status = $1, updated_at = NOW()
      WHERE s.id = $2
        AND EXISTS (
          SELECT 1 FROM shifts sh
          WHERE sh.schedule_id = s.id AND sh.driver_id = $3
        )
      RETURNING s.id, s.status
    `,
      [normalizedStatus, scheduleId, req.user.userId],
    );

    if (result.rows.length === 0)
      return { statusCode: 404, body: { error: "schedule_not_found" } };
    return {
      statusCode: 200,
      body: {
        schedule: {
          id: Number(result.rows[0].id),
          status: result.rows[0].status,
        },
      },
    };
  } catch (err) {
    console.error("PATCH /driver/weekly-schedules/:id/status error:", err);
    reportError({ partofservice: "PATCH /driver/weekly-schedules/:id/status", error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error" } };
  }
}

async function listWeeklySchedules(req) {
  try {
    const result = await db.query(`
      SELECT s.id, s.bus_line_id, s.start_time, s.end_time, s.status, s.day_of_week,
             bl.line_number, bl.start_stop, bl.end_stop,
             sh.id AS shift_id, sh.driver_id, u.usercode AS driver_name
      FROM schedules s
      JOIN bus_lines bl ON bl.id = s.bus_line_id
      LEFT JOIN shifts sh ON sh.schedule_id = s.id
      LEFT JOIN workers.users u ON u.id = sh.driver_id
      ORDER BY s.day_of_week ASC, s.start_time ASC, s.id ASC
    `);
    return {
      statusCode: 200,
      body: {
        schedules: result.rows.map((row) => ({
          id: Number(row.id),
          busLineId: Number(row.bus_line_id),
          lineNumber: row.line_number,
          startStop: row.start_stop,
          endStop: row.end_stop,
          startTime: row.start_time,
          endTime: row.end_time,
          status: row.status,
          dayOfWeek: Number(row.day_of_week),
          shiftId: row.shift_id ? Number(row.shift_id) : null,
          driverId: row.driver_id ? Number(row.driver_id) : null,
          driverName: row.driver_name || null,
        })),
      },
    };
  } catch (err) {
    console.error("GET /admin/weekly-schedules error:", err);
    reportError({ partofservice: "GET /admin/weekly-schedules", error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error" } };
  }
}

async function createWeeklySchedule(req) {
  try {
    const busLineId = Number(req.body?.busLineId);
    const dayOfWeek = Number(req.body?.dayOfWeek);
    const startTime = String(req.body?.startTime || "");
    const endTime = String(req.body?.endTime || "");
    const driverId = req.body?.driverId ? Number(req.body.driverId) : null;

    if (
      !Number.isInteger(busLineId) ||
      !Number.isInteger(dayOfWeek) ||
      dayOfWeek < 0 ||
      dayOfWeek > 6 ||
      !startTime ||
      !endTime
    ) {
      return {
        statusCode: 400,
        body: {
          error: "busLineId, dayOfWeek, startTime and endTime are required",
        },
      };
    }

    const created = await db.query(
      `
      INSERT INTO schedules (bus_line_id, start_time, end_time, status, day_of_week)
      VALUES ($1, $2::time, $3::time, 'planned', $4)
      RETURNING id, bus_line_id, start_time, end_time, status, day_of_week
    `,
      [busLineId, startTime, endTime, dayOfWeek],
    );

    const schedule = created.rows[0];
    if (driverId) {
      await db.query(
        `
        INSERT INTO shifts (schedule_id, driver_id)
        VALUES ($1, $2)
      `,
        [schedule.id, driverId],
      );
    }

    return {
      statusCode: 201,
      body: {
        schedule: {
          id: Number(schedule.id),
          busLineId: Number(schedule.bus_line_id),
          startTime: schedule.start_time,
          endTime: schedule.end_time,
          status: schedule.status,
          dayOfWeek: Number(schedule.day_of_week),
          driverId,
        },
      },
    };
  } catch (err) {
    console.error("POST /admin/weekly-schedules error:", err);
    reportError({ partofservice: "POST /admin/weekly-schedules", error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error" } };
  }
}

async function bulkCreateWeeklySchedules(req) {
  const busLineId = Number(req.body?.busLineId);
  const dayOfWeeks = Array.isArray(req.body?.dayOfWeeks)
    ? req.body.dayOfWeeks
        .map(Number)
        .filter((day) => Number.isInteger(day) && day >= 0 && day <= 6)
    : [];
  const startTimes = Array.isArray(req.body?.startTimes)
    ? [...new Set(req.body.startTimes.map(String).filter(Boolean))]
    : [];
  const driverId = req.body?.driverId ? Number(req.body.driverId) : null;

  if (
    !Number.isInteger(busLineId) ||
    dayOfWeeks.length === 0 ||
    startTimes.length === 0
  ) {
    return {
      statusCode: 400,
      body: { error: "busLineId, dayOfWeeks and startTimes are required" },
    };
  }

  const client = await db.pool.connect();
  try {
    await client.query("BEGIN");
    const line = await client.query(
      "SELECT estimated_duration_minutes FROM bus_lines WHERE id = $1",
      [busLineId],
    );
    if (line.rows.length === 0) {
      await client.query("ROLLBACK");
      return { statusCode: 404, body: { error: "bus_line_not_found" } };
    }

    const duration = Number(line.rows[0].estimated_duration_minutes) || 60;
    const created = [];
    for (const dayOfWeek of dayOfWeeks) {
      for (const startTime of startTimes) {
        const result = await client.query(
          `INSERT INTO schedules
            (bus_line_id, start_time, end_time, status, day_of_week)
           VALUES ($1, $2::time, ($2::time + ($3::text || ' minutes')::interval)::time, 'planned', $4)
           RETURNING id, bus_line_id, start_time, end_time, status, day_of_week`,
          [busLineId, startTime, duration, dayOfWeek],
        );
        const schedule = result.rows[0];
        if (driverId) {
          await client.query(
            "INSERT INTO shifts (schedule_id, driver_id) VALUES ($1, $2)",
            [schedule.id, driverId],
          );
        }
        created.push(schedule);
      }
    }

    await client.query("COMMIT");
    return {
      statusCode: 201,
      body: {
        createdCount: created.length,
        schedules: created.map((schedule) => ({
          id: Number(schedule.id),
          busLineId: Number(schedule.bus_line_id),
          startTime: schedule.start_time,
          endTime: schedule.end_time,
          status: schedule.status,
          dayOfWeek: Number(schedule.day_of_week),
          driverId,
        })),
      },
    };
  } catch (err) {
    await client.query("ROLLBACK");
    console.error("POST /admin/weekly-schedules/bulk error:", err);
    reportError({ partofservice: "POST /admin/weekly-schedules/bulk", error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error" } };
  } finally {
    client.release();
  }
}

async function updateWeeklySchedule(req) {
  try {
    const scheduleId = Number(req.params.scheduleId);
    const busLineId = Number(req.body?.busLineId);
    const dayOfWeek = Number(req.body?.dayOfWeek);
    const startTime = String(req.body?.startTime || "");
    const endTime = String(req.body?.endTime || "");
    if (
      !Number.isInteger(scheduleId) ||
      !Number.isInteger(busLineId) ||
      !Number.isInteger(dayOfWeek) ||
      dayOfWeek < 0 ||
      dayOfWeek > 6 ||
      !startTime ||
      !endTime
    ) {
      return { statusCode: 400, body: { error: "invalid_schedule" } };
    }

    const result = await db.query(
      `
      UPDATE schedules
      SET bus_line_id = $2, start_time = $3::time, end_time = $4::time,
          day_of_week = $5, updated_at = NOW()
      WHERE id = $1
      RETURNING id, bus_line_id, start_time, end_time, status, day_of_week
    `,
      [scheduleId, busLineId, startTime, endTime, dayOfWeek],
    );
    if (result.rows.length === 0)
      return { statusCode: 404, body: { error: "schedule_not_found" } };
    return { statusCode: 200, body: { schedule: result.rows[0] } };
  } catch (err) {
    console.error("PUT /admin/weekly-schedules error:", err);
    reportError({ partofservice: "PUT /admin/weekly-schedules", error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error" } };
  }
}

async function updateWeeklyScheduleShift(req) {
  try {
    const scheduleId = Number(req.params.scheduleId);
    const driverId = req.body?.driverId ? Number(req.body.driverId) : null;
    if (!Number.isInteger(scheduleId))
      return { statusCode: 400, body: { error: "invalid_schedule_id" } };
    await db.query("DELETE FROM shifts WHERE schedule_id = $1", [
      scheduleId,
    ]);
    if (driverId) {
      await db.query(
        "INSERT INTO shifts (schedule_id, driver_id) VALUES ($1, $2)",
        [scheduleId, driverId],
      );
    }
    return { statusCode: 200, body: { scheduleId, driverId } };
  } catch (err) {
    console.error("PUT /admin/weekly-schedules/:id/shift error:", err);
    reportError({ partofservice: "PUT /admin/weekly-schedules/:id/shift", error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error" } };
  }
}

async function deleteWeeklySchedule(req) {
  try {
    const scheduleId = Number(req.params.scheduleId);
    if (!Number.isInteger(scheduleId))
      return { statusCode: 400, body: { error: "invalid_schedule_id" } };
    const result = await db.query(
      "DELETE FROM schedules WHERE id = $1 RETURNING id",
      [scheduleId],
    );
    if (result.rows.length === 0)
      return { statusCode: 404, body: { error: "schedule_not_found" } };
    return { statusCode: 200, body: { success: true, scheduleId } };
  } catch (err) {
    console.error("DELETE /admin/weekly-schedules error:", err);
    reportError({ partofservice: "DELETE /admin/weekly-schedules", error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error" } };
  }
}

module.exports = {
  updateWeeklyScheduleStatus,
  listWeeklySchedules,
  createWeeklySchedule,
  bulkCreateWeeklySchedules,
  updateWeeklySchedule,
  updateWeeklyScheduleShift,
  deleteWeeklySchedule,
};