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.BrandEvent;
import com.kaidi.oa.domain.EventGuest;
import com.kaidi.oa.repository.BrandEventRepository;
import com.kaidi.oa.repository.EventGuestRepository;
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.RestController;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.List;

/**
 * 品牌推广部·活动嘉宾管理（活动策划与执行·模块4深化）。
 *
 * <p>为 {@link BrandEvent} 下达嘉宾邀请（{@link EventGuest}），跟踪邀请状态
 * （待邀请→已邀请→已确认/已拒绝→已签到/未出席），支持到场统计。
 * /checkin 端点模拟现场扫码签到，更新 checkinTime 并推进 inviteStatus=已签到。
 * /stats 端点聚合邀请/确认/签到人数，支持实时大屏显示。
 */
@RestController
@RequestMapping("/api/oa/event-guests")
public class EventGuestController {

    private final EventGuestRepository guestRepo;
    private final BrandEventRepository eventRepo;

    public EventGuestController(EventGuestRepository guestRepo, BrandEventRepository eventRepo) {
        this.guestRepo = guestRepo;
        this.eventRepo = eventRepo;
    }

    // ==================== CRUD ====================

    @GetMapping("/by-event/{eventId}")
    public ApiResp<List<EventGuest>> listByEvent(@PathVariable Long eventId) {
        findEvent(eventId);
        return ApiResp.ok(guestRepo.findByEventIdOrderByIdAsc(eventId));
    }

    @GetMapping("/{id}")
    public ApiResp<EventGuest> get(@PathVariable Long id) {
        return ApiResp.ok(findGuest(id));
    }

    public record GuestRequest(
            Long eventId, String guestName, String organization, String title,
            String phone, String email, String guestType, String specialRequirements, String remark) {
    }

    @PostMapping
    public ApiResp<EventGuest> create(@RequestBody GuestRequest req) {
        if (req.eventId() == null) {
            throw new ApiException(400, "eventId 不能为空");
        }
        if (req.guestName() == null || req.guestName().isBlank()) {
            throw new ApiException(400, "嘉宾姓名(guestName) 不能为空");
        }
        BrandEvent e = findEvent(req.eventId());
        if ("已总结".equals(e.getStatus()) || "已取消".equals(e.getStatus())) {
            throw new ApiException(409, "「" + e.getStatus() + "」活动不能再添加嘉宾");
        }
        EventGuest g = new EventGuest();
        g.setEventId(e.getId());
        g.setEventName(e.getName());
        g.setGuestName(req.guestName());
        g.setOrganization(req.organization());
        g.setTitle(req.title());
        g.setPhone(req.phone());
        g.setEmail(req.email());
        g.setGuestType(req.guestType() == null || req.guestType().isBlank() ? "合作伙伴" : req.guestType());
        g.setSpecialRequirements(req.specialRequirements());
        g.setRemark(req.remark());
        g.setInviteStatus("待邀请");
        g.setCreatedAt(Instant.now());
        return ApiResp.ok(guestRepo.save(g));
    }

    @PatchMapping("/{id}")
    public ApiResp<EventGuest> update(@PathVariable Long id, @RequestBody GuestRequest req) {
        EventGuest g = findGuest(id);
        if (req.guestName() != null && !req.guestName().isBlank()) g.setGuestName(req.guestName());
        if (req.organization() != null) g.setOrganization(req.organization());
        if (req.title() != null) g.setTitle(req.title());
        if (req.phone() != null) g.setPhone(req.phone());
        if (req.email() != null) g.setEmail(req.email());
        if (req.guestType() != null) g.setGuestType(req.guestType());
        if (req.specialRequirements() != null) g.setSpecialRequirements(req.specialRequirements());
        if (req.remark() != null) g.setRemark(req.remark());
        return ApiResp.ok(guestRepo.save(g));
    }

    @DeleteMapping("/{id}")
    public ApiResp<Void> delete(@PathVariable Long id) {
        if (!guestRepo.existsById(id)) {
            throw new NotFoundException("event guest not found: " + id);
        }
        guestRepo.deleteById(id);
        return ApiResp.ok(null);
    }

    // ==================== 邀请状态流转 ====================

    public record InviteStatusRequest(String inviteStatus, String date) {
    }

    /** 更新邀请状态（已邀请/已确认/已拒绝）。 */
    @PostMapping("/{id}/update-status")
    public ApiResp<EventGuest> updateStatus(@PathVariable Long id, @RequestBody InviteStatusRequest req) {
        EventGuest g = findGuest(id);
        String allowed = "已邀请,已确认,已拒绝";
        if (req.inviteStatus() == null || !allowed.contains(req.inviteStatus())) {
            throw new ApiException(400, "状态只能为：" + allowed);
        }
        g.setInviteStatus(req.inviteStatus());
        String today = java.time.LocalDate.now().toString();
        if ("已邀请".equals(req.inviteStatus())) {
            g.setInvitedDate(req.date() == null ? today : req.date());
        } else if ("已确认".equals(req.inviteStatus())) {
            g.setConfirmedDate(req.date() == null ? today : req.date());
        }
        return ApiResp.ok(guestRepo.save(g));
    }

    /** 现场签到（已确认/已邀请 → 已签到），记录签到时间。 */
    @PostMapping("/{id}/checkin")
    public ApiResp<EventGuest> checkin(@PathVariable Long id) {
        EventGuest g = findGuest(id);
        if ("已签到".equals(g.getInviteStatus())) {
            throw new ApiException(409, "嘉宾已签到，不可重复操作");
        }
        if ("已拒绝".equals(g.getInviteStatus()) || "未出席".equals(g.getInviteStatus())) {
            throw new ApiException(409, "嘉宾状态「" + g.getInviteStatus() + "」，不可签到");
        }
        g.setInviteStatus("已签到");
        g.setCheckinTime(LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        return ApiResp.ok(guestRepo.save(g));
    }

    /** 标记未出席（活动结束后，已确认/已邀请但未签到的嘉宾）。 */
    @PostMapping("/{id}/absent")
    public ApiResp<EventGuest> markAbsent(@PathVariable Long id) {
        EventGuest g = findGuest(id);
        if ("已签到".equals(g.getInviteStatus())) {
            throw new ApiException(409, "已签到嘉宾不能标记为未出席");
        }
        g.setInviteStatus("未出席");
        return ApiResp.ok(guestRepo.save(g));
    }

    // ==================== 签到统计（大屏聚合）====================

    public record GuestStats(Long eventId, String eventName, int total, int invited, int confirmed,
                              int checkedIn, int absent, int refused, int pending,
                              double checkinRate) {
    }

    /** 嘉宾签到统计：邀请/确认/签到/缺席人数，支持活动大屏实时显示。 */
    @GetMapping("/stats/{eventId}")
    public ApiResp<GuestStats> stats(@PathVariable Long eventId) {
        BrandEvent e = findEvent(eventId);
        List<EventGuest> guests = guestRepo.findByEventIdOrderByIdAsc(eventId);
        int total = guests.size();
        int invited = 0, confirmed = 0, checkedIn = 0, absent = 0, refused = 0, pending = 0;
        for (EventGuest g : guests) {
            switch (g.getInviteStatus() == null ? "待邀请" : g.getInviteStatus()) {
                case "待邀请" -> pending++;
                case "已邀请" -> invited++;
                case "已确认" -> confirmed++;
                case "已签到" -> checkedIn++;
                case "未出席" -> absent++;
                case "已拒绝" -> refused++;
                default -> pending++;
            }
        }
        double rate = total == 0 ? 0 : Math.round(checkedIn * 1000.0 / total) / 10.0;
        return ApiResp.ok(new GuestStats(eventId, e.getName(), total, invited, confirmed,
                checkedIn, absent, refused, pending, rate));
    }

    // ==================== 私有工具 ====================

    private BrandEvent findEvent(Long id) {
        return eventRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("brand event not found: " + id));
    }

    private EventGuest findGuest(Long id) {
        return guestRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("event guest not found: " + id));
    }
}