package com.kaidi.oa.web;

import com.kaidi.oa.common.ApiException;
import com.kaidi.oa.common.ApiResp;
import com.kaidi.oa.common.NotFoundException;
import com.kaidi.oa.domain.AdminShuttleBus;
import com.kaidi.oa.domain.AdminShuttlePassenger;
import com.kaidi.oa.repository.AdminShuttleBusRepository;
import com.kaidi.oa.repository.AdminShuttlePassengerRepository;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PatchMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.time.Instant;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 * 行政/办公室·通勤班车管理（补深车辆管理缺口）。
 * 固定线路班车排班、乘客预约统计。
 * 班车档案：/api/oa/admin-shuttles/buses
 * 乘客预约：/api/oa/admin-shuttles/passengers
 */
@RestController
@RequestMapping("/api/oa/admin-shuttles")
public class AdminShuttleController {

    private final AdminShuttleBusRepository busRepo;
    private final AdminShuttlePassengerRepository passengerRepo;

    public AdminShuttleController(AdminShuttleBusRepository busRepo,
                                  AdminShuttlePassengerRepository passengerRepo) {
        this.busRepo = busRepo;
        this.passengerRepo = passengerRepo;
    }

    // ---------- 班车路线档案 ----------

    @GetMapping("/buses")
    public ApiResp<List<AdminShuttleBus>> listBuses(
            @RequestParam(required = false) String status) {
        if (status != null && !status.isBlank()) {
            return ApiResp.ok(busRepo.findByStatusOrderByIdDesc(status));
        }
        return ApiResp.ok(busRepo.findAllByOrderByRouteNameAsc());
    }

    @GetMapping("/buses/{id}")
    public ApiResp<AdminShuttleBus> getBus(@PathVariable Long id) {
        return ApiResp.ok(busRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("shuttle bus not found: " + id)));
    }

    public record BusRequest(
            String routeName, String startStop, String endStop, String stops,
            String departureTime, String returnTime, String vehiclePlate, String driver,
            Integer seats, String runDays, String status, String remark) {
    }

    @PostMapping("/buses")
    public ApiResp<AdminShuttleBus> createBus(@RequestBody BusRequest req) {
        if (req.routeName() == null || req.routeName().isBlank()) {
            throw new ApiException(400, "路线名称(routeName) 不能为空");
        }
        AdminShuttleBus b = new AdminShuttleBus();
        b.setRouteName(req.routeName());
        b.setStartStop(req.startStop());
        b.setEndStop(req.endStop());
        b.setStops(req.stops());
        b.setDepartureTime(req.departureTime());
        b.setReturnTime(req.returnTime());
        b.setVehiclePlate(req.vehiclePlate());
        b.setDriver(req.driver());
        b.setSeats(req.seats() == null ? 20 : req.seats());
        b.setBookedCount(0);
        b.setRunDays(req.runDays() == null || req.runDays().isBlank() ? "工作日" : req.runDays());
        b.setStatus(req.status() == null || req.status().isBlank() ? "运营中" : req.status());
        b.setRemark(req.remark());
        b.setCreatedAt(Instant.now());
        b.setUpdatedAt(Instant.now());
        return ApiResp.ok(busRepo.save(b));
    }

    @PatchMapping("/buses/{id}")
    public ApiResp<AdminShuttleBus> updateBus(@PathVariable Long id, @RequestBody BusRequest req) {
        AdminShuttleBus b = busRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("shuttle bus not found: " + id));
        if (req.routeName() != null && !req.routeName().isBlank()) b.setRouteName(req.routeName());
        if (req.startStop() != null) b.setStartStop(req.startStop());
        if (req.endStop() != null) b.setEndStop(req.endStop());
        if (req.stops() != null) b.setStops(req.stops());
        if (req.departureTime() != null) b.setDepartureTime(req.departureTime());
        if (req.returnTime() != null) b.setReturnTime(req.returnTime());
        if (req.vehiclePlate() != null) b.setVehiclePlate(req.vehiclePlate());
        if (req.driver() != null) b.setDriver(req.driver());
        if (req.seats() != null) b.setSeats(req.seats());
        if (req.runDays() != null && !req.runDays().isBlank()) b.setRunDays(req.runDays());
        if (req.status() != null && !req.status().isBlank()) b.setStatus(req.status());
        if (req.remark() != null) b.setRemark(req.remark());
        b.setUpdatedAt(Instant.now());
        return ApiResp.ok(busRepo.save(b));
    }

    @DeleteMapping("/buses/{id}")
    public ApiResp<Void> deleteBus(@PathVariable Long id) {
        if (!busRepo.existsById(id)) throw new NotFoundException("shuttle bus not found: " + id);
        busRepo.deleteById(id);
        return ApiResp.ok(null);
    }

    // ---------- 乘客预约 ----------

    @GetMapping("/passengers")
    public ApiResp<List<AdminShuttlePassenger>> listPassengers(
            @RequestParam(required = false) Long shuttleId,
            @RequestParam(required = false) String rideDate,
            @RequestParam(required = false) String status) {
        if (shuttleId != null && rideDate != null && !rideDate.isBlank()) {
            return ApiResp.ok(passengerRepo.findByShuttleIdAndRideDate(shuttleId, rideDate));
        }
        if (status != null && !status.isBlank()) {
            return ApiResp.ok(passengerRepo.findByStatus(status));
        }
        // default: today
        String today = LocalDate.now().toString();
        List<AdminShuttlePassenger> all = new ArrayList<>();
        for (AdminShuttleBus bus : busRepo.findAllByOrderByRouteNameAsc()) {
            all.addAll(passengerRepo.findByShuttleIdAndRideDate(bus.getId(),
                    rideDate != null ? rideDate : today));
        }
        return ApiResp.ok(all);
    }

    public record PassengerRequest(
            Long shuttleId, String passenger, String dept, String rideDate,
            String direction, String boardStop) {
    }

    /** 预约乘坐：检查座位余量，不超过班车座位数。 */
    @PostMapping("/passengers")
    @Transactional
    public ApiResp<AdminShuttlePassenger> book(@RequestBody PassengerRequest req) {
        if (req.shuttleId() == null) throw new ApiException(400, "shuttleId 不能为空");
        if (req.passenger() == null || req.passenger().isBlank()) {
            throw new ApiException(400, "乘客姓名(passenger) 不能为空");
        }
        AdminShuttleBus bus = busRepo.findById(req.shuttleId())
                .orElseThrow(() -> new NotFoundException("shuttle bus not found: " + req.shuttleId()));
        if (!"运营中".equals(bus.getStatus())) {
            throw new ApiException(409, "该班车当前状态为「" + bus.getStatus() + "」，不可预约");
        }
        String rideDate = req.rideDate() == null || req.rideDate().isBlank()
                ? LocalDate.now().toString() : req.rideDate();
        // 检查同日同班车座位余量
        int booked = passengerRepo.countByShuttleIdAndRideDateAndStatus(req.shuttleId(), rideDate, "已预约");
        if (bus.getSeats() != null && booked >= bus.getSeats()) {
            throw new ApiException(409, "该班车当日座位已满（" + bus.getSeats() + "座）");
        }
        AdminShuttlePassenger p = new AdminShuttlePassenger();
        p.setShuttleId(req.shuttleId());
        p.setPassenger(req.passenger());
        p.setDept(req.dept());
        p.setRideDate(rideDate);
        p.setDirection(req.direction() == null || req.direction().isBlank() ? "去" : req.direction());
        p.setBoardStop(req.boardStop());
        p.setStatus("已预约");
        p.setCreatedAt(Instant.now());
        // 更新班车预约人数
        bus.setBookedCount((bus.getBookedCount() == null ? 0 : bus.getBookedCount()) + 1);
        busRepo.save(bus);
        return ApiResp.ok(passengerRepo.save(p));
    }

    /** 取消预约：已预约 → 已取消，释放座位。 */
    @PostMapping("/passengers/{id}/cancel")
    @Transactional
    public ApiResp<AdminShuttlePassenger> cancelBooking(@PathVariable Long id) {
        AdminShuttlePassenger p = passengerRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("passenger not found: " + id));
        if (!"已预约".equals(p.getStatus())) {
            throw new ApiException(409, "仅「已预约」可取消，当前：" + p.getStatus());
        }
        p.setStatus("已取消");
        passengerRepo.save(p);
        busRepo.findById(p.getShuttleId()).ifPresent(bus -> {
            int prev = bus.getBookedCount() == null ? 0 : bus.getBookedCount();
            bus.setBookedCount(Math.max(0, prev - 1));
            busRepo.save(bus);
        });
        return ApiResp.ok(p);
    }

    /** 标记已乘坐：已预约 → 已乘坐。 */
    @PostMapping("/passengers/{id}/checkin")
    @Transactional
    public ApiResp<AdminShuttlePassenger> checkin(@PathVariable Long id) {
        AdminShuttlePassenger p = passengerRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("passenger not found: " + id));
        if (!"已预约".equals(p.getStatus())) {
            throw new ApiException(409, "仅「已预约」可签到，当前：" + p.getStatus());
        }
        p.setStatus("已乘坐");
        return ApiResp.ok(passengerRepo.save(p));
    }

    // ---------- 乘客统计 ----------

    public record ShuttleStatsRow(String routeName, String rideDate, long booked, long ridden, long cancelled) {
    }

    /** 班车乘客统计：按班车+日期聚合。 */
    @GetMapping("/stats")
    public ApiResp<List<ShuttleStatsRow>> stats(
            @RequestParam(required = false) String startDate,
            @RequestParam(required = false) String endDate) {
        Map<String, long[]> map = new LinkedHashMap<>();
        for (AdminShuttleBus bus : busRepo.findAllByOrderByRouteNameAsc()) {
            List<AdminShuttlePassenger> passengers = passengerRepo.findByShuttleIdAndRideDate(
                    bus.getId(), startDate == null ? LocalDate.now().toString() : startDate);
            for (AdminShuttlePassenger p : passengers) {
                String key = bus.getRouteName() + "||" + p.getRideDate();
                long[] cnt = map.computeIfAbsent(key, k -> new long[3]);
                if ("已预约".equals(p.getStatus())) cnt[0]++;
                else if ("已乘坐".equals(p.getStatus())) cnt[1]++;
                else if ("已取消".equals(p.getStatus())) cnt[2]++;
            }
        }
        List<ShuttleStatsRow> rows = new ArrayList<>();
        for (Map.Entry<String, long[]> e : map.entrySet()) {
            String[] parts = e.getKey().split("\\|\\|");
            long[] cnt = e.getValue();
            rows.add(new ShuttleStatsRow(parts[0], parts.length > 1 ? parts[1] : "", cnt[0], cnt[1], cnt[2]));
        }
        return ApiResp.ok(rows);
    }
}