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.MeetingActionItem;
import com.kaidi.oa.domain.MeetingMinute;
import com.kaidi.oa.repository.MeetingActionItemRepository;
import com.kaidi.oa.repository.MeetingMinuteRepository;
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.List;

/**
 * 会议纪要待办与跟踪（知识产权部，需求功能13 — 补深 PARTIAL）。
 *
 * 补深审计缺口：会议纪要无自动生成待办+跟踪+责任人。
 *  - generate-from-minute：读取 MeetingMinute.decisions（决议，按行/分号拆分），自动生成待办事项，
 *    与责任人/截止日关联，状态置「待办」；
 *  - 手工增删改 + 状态流转（待办→进行中→已完成/已取消）跟踪完成；
 *  - overdue 端点列出逾期未完成待办，board 端点给出完成率看板。
 *
 * 新控制器默认受 AuthInterceptor 保护。
 */
@RestController
@RequestMapping("/api/oa/meeting-action-items")
public class MeetingActionItemController {

    private final MeetingActionItemRepository repo;
    private final MeetingMinuteRepository minuteRepo;

    public MeetingActionItemController(MeetingActionItemRepository repo,
                                       MeetingMinuteRepository minuteRepo) {
        this.repo = repo;
        this.minuteRepo = minuteRepo;
    }

    @GetMapping
    public ApiResp<List<MeetingActionItem>> list(@RequestParam(required = false) Long minuteId,
                                                 @RequestParam(required = false) String assignee,
                                                 @RequestParam(required = false) String status) {
        if (minuteId != null) {
            return ApiResp.ok(repo.findByMinuteIdOrderByIdAsc(minuteId));
        }
        if (assignee != null && !assignee.isBlank()) {
            return ApiResp.ok(repo.findByAssigneeOrderByIdDesc(assignee));
        }
        if (status != null && !status.isBlank()) {
            return ApiResp.ok(repo.findByStatus(status));
        }
        return ApiResp.ok(repo.findAll());
    }

    public record ItemRequest(Long minuteId, String content, String assignee, String dueDate) {
    }

    @PostMapping
    @Transactional
    public ApiResp<MeetingActionItem> create(@RequestBody ItemRequest req) {
        if (req.content() == null || req.content().isBlank()) {
            throw new ApiException(400, "待办内容不能为空");
        }
        MeetingActionItem it = new MeetingActionItem();
        it.setMinuteId(req.minuteId());
        if (req.minuteId() != null) {
            minuteRepo.findById(req.minuteId()).ifPresent(m -> it.setMinuteTitle(m.getTitle()));
        }
        it.setContent(req.content());
        it.setAssignee(req.assignee());
        it.setDueDate(req.dueDate());
        it.setStatus("待办");
        it.setCreatedAt(Instant.now());
        it.setUpdatedAt(Instant.now());
        return ApiResp.ok(repo.save(it));
    }

    public record GenerateRequest(Long minuteId, String defaultAssignee, String defaultDueDate) {
    }

    /**
     * 从会议纪要自动生成待办：读取纪要 decisions（按换行/分号/；拆分为多条），逐条建为「待办」，
     * 责任人/截止日缺省用入参兜底。已存在的同纪要待办不重复生成（按内容去重）。
     */
    @PostMapping("/generate-from-minute")
    @Transactional
    public ApiResp<List<MeetingActionItem>> generate(@RequestBody GenerateRequest req) {
        if (req.minuteId() == null) {
            throw new ApiException(400, "缺少会议纪要 minuteId");
        }
        MeetingMinute m = minuteRepo.findById(req.minuteId())
                .orElseThrow(() -> new NotFoundException("会议纪要不存在：" + req.minuteId()));
        String decisions = m.getDecisions();
        if (decisions == null || decisions.isBlank()) {
            throw new ApiException(409, "该纪要无决议内容（decisions 为空），无法生成待办");
        }
        List<MeetingActionItem> existing = repo.findByMinuteIdOrderByIdAsc(req.minuteId());
        List<MeetingActionItem> created = new ArrayList<>();
        Instant now = Instant.now();
        for (String raw : decisions.split("[\\r\\n;；]+")) {
            String line = raw.trim();
            if (line.isEmpty()) {
                continue;
            }
            boolean dup = existing.stream().anyMatch(x -> line.equals(x.getContent()));
            if (dup) {
                continue;
            }
            MeetingActionItem it = new MeetingActionItem();
            it.setMinuteId(m.getId());
            it.setMinuteTitle(m.getTitle());
            it.setContent(line);
            it.setAssignee(req.defaultAssignee());
            it.setDueDate(req.defaultDueDate());
            it.setStatus("待办");
            it.setCreatedAt(now);
            it.setUpdatedAt(now);
            created.add(it);
        }
        if (created.isEmpty()) {
            throw new ApiException(409, "未解析出新的待办（决议已全部生成）");
        }
        return ApiResp.ok(repo.saveAll(created));
    }

    @PatchMapping("/{id}")
    @Transactional
    public ApiResp<MeetingActionItem> update(@PathVariable Long id, @RequestBody ItemRequest req) {
        MeetingActionItem it = find(id);
        if (req.content() != null && !req.content().isBlank()) it.setContent(req.content());
        if (req.assignee() != null) it.setAssignee(req.assignee());
        if (req.dueDate() != null) it.setDueDate(req.dueDate());
        it.setUpdatedAt(Instant.now());
        return ApiResp.ok(repo.save(it));
    }

    public record StatusRequest(String status) {
    }

    /** 状态流转：待办 → 进行中 → 已完成；任意可取消。完成时回填完成日。 */
    @PostMapping("/{id}/status")
    @Transactional
    public ApiResp<MeetingActionItem> setStatus(@PathVariable Long id, @RequestBody StatusRequest req) {
        MeetingActionItem it = find(id);
        String to = req.status() == null ? "" : req.status().trim();
        if (!List.of("待办", "进行中", "已完成", "已取消").contains(to)) {
            throw new ApiException(400, "未知状态：" + to);
        }
        it.setStatus(to);
        it.setCompletedDate("已完成".equals(to) ? LocalDate.now().toString() : null);
        it.setUpdatedAt(Instant.now());
        return ApiResp.ok(repo.save(it));
    }

    @DeleteMapping("/{id}")
    @Transactional
    public ApiResp<Void> delete(@PathVariable Long id) {
        find(id);
        repo.deleteById(id);
        return ApiResp.ok(null);
    }

    // ---------- 逾期 + 看板 ----------

    public record OverdueItem(Long id, String content, String assignee, String dueDate,
                              long daysOverdue, String minuteTitle) {
    }

    @GetMapping("/overdue")
    public ApiResp<List<OverdueItem>> overdue() {
        LocalDate today = LocalDate.now();
        List<OverdueItem> out = new ArrayList<>();
        for (MeetingActionItem it : repo.findAll()) {
            if ("已完成".equals(it.getStatus()) || "已取消".equals(it.getStatus())) {
                continue;
            }
            LocalDate due = parseDateOrNull(it.getDueDate());
            if (due == null || !due.isBefore(today)) {
                continue;
            }
            long over = java.time.temporal.ChronoUnit.DAYS.between(due, today);
            out.add(new OverdueItem(it.getId(), it.getContent(), it.getAssignee(),
                    it.getDueDate(), over, it.getMinuteTitle()));
        }
        out.sort((a, b) -> Long.compare(b.daysOverdue(), a.daysOverdue()));
        return ApiResp.ok(out);
    }

    public record Board(int total, int pending, int inProgress, int done, int cancelled,
                        double completionRate) {
    }

    @GetMapping("/board")
    public ApiResp<Board> board() {
        List<MeetingActionItem> all = repo.findAll();
        int pending = 0;
        int inProgress = 0;
        int done = 0;
        int cancelled = 0;
        for (MeetingActionItem it : all) {
            switch (it.getStatus() == null ? "" : it.getStatus()) {
                case "待办" -> pending++;
                case "进行中" -> inProgress++;
                case "已完成" -> done++;
                case "已取消" -> cancelled++;
                default -> {
                    // unknown status ignored from buckets
                }
            }
        }
        int effective = all.size() - cancelled;
        double rate = effective <= 0 ? 0d : Math.round((done * 10000d) / effective) / 100d;
        return ApiResp.ok(new Board(all.size(), pending, inProgress, done, cancelled, rate));
    }

    private MeetingActionItem find(Long id) {
        return repo.findById(id)
                .orElseThrow(() -> new NotFoundException("待办事项不存在：" + id));
    }

    private static LocalDate parseDateOrNull(String s) {
        if (s == null || s.isBlank()) {
            return null;
        }
        try {
            String t = s.trim();
            return LocalDate.parse(t.substring(0, Math.min(10, t.length())));
        } catch (RuntimeException e) {
            return null;
        }
    }
}