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

// Fleet repository methods (PostgreSQL mode).

async function listFleetBuses(req) {
  try {
    const result = await db.query(`
      SELECT id, name, seat_capacity, license_plate
      FROM fleet.bus
      ORDER BY id ASC
    `);

    // Get all schedules to check for conflicts
    const schedulesResult = await db.query(
      `SELECT * FROM schedules WHERE status IN ('planned', 'active')`,
    );
    const schedules = schedulesResult.rows.map((row) => ({
      ...row,
      weekdays: parseWeekdaysValue(row.weekdays),
    }));

    return {
      statusCode: 200,
      body: {
        buses: result.rows.map((row) => {
          const busId = row.id;
          const now = new Date();
          const tomorrow = new Date(now);
          tomorrow.setDate(tomorrow.getDate() + 1);
          const isAvailable = !checkBusConflict(
            busId,
            now.toISOString(),
            tomorrow.toISOString(),
            [],
            schedules,
          );

          return {
            id: row.id,
            name: row.name,
            seatCapacity: row.seat_capacity,
            licensePlate: row.license_plate,
            available: isAvailable,
          };
        }),
      },
    };
  } catch (err) {
    console.error(err);
    reportError({ partofservice: `${req.method} ${req.originalUrl}`, error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error", details: err.message } };
  }
}

async function createFleetBus(req) {
  try {
    const { name, seatCapacity, licensePlate } = req.body;

    if (!name || seatCapacity === undefined || !licensePlate) {
      return { statusCode: 400, body: { error: "missing_required_fields" } };
    }

    const result = await db.query(
      `
      WITH next_id AS (
        SELECT COALESCE(MAX(id), 0) + 1 AS id FROM fleet.bus
      )
      INSERT INTO fleet.bus (id, name, seat_capacity, license_plate)
      SELECT next_id.id, $1, $2, $3
      FROM next_id
      RETURNING id, name, seat_capacity, license_plate
    `,
      [name, seatCapacity, licensePlate],
    );

    const bus = result.rows[0];
    return {
      statusCode: 201,
      body: {
        bus: {
          id: bus.id,
          name: bus.name,
          seatCapacity: bus.seat_capacity,
          licensePlate: bus.license_plate,
        },
      },
    };
  } catch (err) {
    console.error(err);
    reportError({ partofservice: `${req.method} ${req.originalUrl}`, error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error", details: err.message } };
  }
}

async function updateFleetBus(req) {
  try {
    const { busId } = req.params;
    const { name, seatCapacity, licensePlate } = req.body;

    if (!busId || !Number.isFinite(Number(busId))) {
      return { statusCode: 400, body: { error: "invalid_bus_id" } };
    }

    const result = await db.query(
      `
      UPDATE fleet.bus
      SET name = COALESCE($1, name), seat_capacity = COALESCE($2, seat_capacity), license_plate = COALESCE($3, license_plate), updated_at = NOW()
      WHERE id = $4
      RETURNING id, name, seat_capacity, license_plate
    `,
      [name ?? null, seatCapacity ?? null, licensePlate ?? null, busId],
    );

    if (!result.rows[0])
      return { statusCode: 404, body: { error: "bus_not_found" } };

    const bus = result.rows[0];
    return {
      statusCode: 200,
      body: {
        bus: {
          id: bus.id,
          name: bus.name,
          seatCapacity: bus.seat_capacity,
          licensePlate: bus.license_plate,
        },
      },
    };
  } catch (err) {
    console.error(err);
    reportError({ partofservice: `${req.method} ${req.originalUrl}`, error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error", details: err.message } };
  }
}

async function deleteFleetBus(req) {
  try {
    const { busId } = req.params;
    if (!busId || !Number.isFinite(Number(busId))) {
      return { statusCode: 400, body: { error: "invalid_bus_id" } };
    }

    const result = await db.query(
      `DELETE FROM fleet.bus WHERE id = $1 RETURNING id, name`,
      [busId],
    );
    if (result.rows.length === 0)
      return { statusCode: 404, body: { error: "bus_not_found" } };
    return { statusCode: 200, body: { success: true, bus: result.rows[0] } };
  } catch (err) {
    console.error(err);
    reportError({ partofservice: `${req.method} ${req.originalUrl}`, error: err.stack || err.message });
    return { statusCode: 500, body: { error: "internal_error", details: err.message } };
  }
}

module.exports = { listFleetBuses, createFleetBus, updateFleetBus, deleteFleetBus };