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.LegalRiskMeasure;
import com.kaidi.oa.repository.LegalRiskMeasureRepository;
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.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 * 风险应对措施执行跟踪（法务合规·风险控制与评估）。
 * 针对中高风险制定的具体应对措施清单，分配责任人/部门/完成时限，跟踪执行状态。
 * 提供逾期预警接口（/overdue），列出 dueDate < today 且 status 非已完成/已取消 的超期措施。
 * 状态流转：待执行→执行中→已完成（或随时取消）。
 *
 * 读口含责任人/措施描述等内部治理信息，需认证。
 */
@RestController
@RequestMapping("/api/oa/legal-risk-measures")
public class LegalRiskMeasureController {

    private static final List<String> CLOSED_STATUSES = List.of("已完成", "已取消");

    private final LegalRiskMeasureRepository repo;

    public LegalRiskMeasureController(LegalRiskMeasureRepository repo) {
        this.repo = repo;
    }

    @GetMapping
    public ApiResp<List<LegalRiskMeasure>> list(
            @RequestParam(required = false) String status,
            @RequestParam(required = false) Long riskAssessId,
            @RequestParam(required = false) String owner,
            @RequestParam(required = false) String ownerDept) {
        if (riskAssessId != null) {
            return ApiResp.ok(repo.findByRiskAssessId(riskAssessId));
        }
        if (status != null && !status.isBlank()) {
            return ApiResp.ok(repo.findByStatus(status));
        }
        if (owner != null && !owner.isBlank()) {
            return ApiResp.ok(repo.findByOwner(owner));
        }
        if (ownerDept != null && !ownerDept.isBlank()) {
            return ApiResp.ok(repo.findByOwnerDept(ownerDept));
        }
        return ApiResp.ok(repo.findAll());
    }

    @GetMapping("/{id}")
    public ApiResp<LegalRiskMeasure> get(@PathVariable Long id) {
        return ApiResp.ok(repo.findById(id)
                .orElseThrow(() -> new NotFoundException("风险应对措施不存在: " + id)));
    }

    public record MeasureRequest(
            Long riskAssessId, String measureNo, String title, String description,
            String owner, String ownerDept, String dueDate, String status,
            String completedDate, String result) {
    }

    @PostMapping
    @Transactional
    public ApiResp<LegalRiskMeasure> create(@RequestBody MeasureRequest req) {
        if (req.title() == null || req.title().isBlank()) {
            throw new ApiException(400, "措施标题(title) 不能为空");
        }
        if (req.dueDate() == null || req.dueDate().isBlank()) {
            throw new ApiException(400, "完成时限(dueDate) 不能为空");
        }
        LegalRiskMeasure m = new LegalRiskMeasure();
        m.setRiskAssessId(req.riskAssessId());
        m.setMeasureNo(req.measureNo() == null || req.measureNo().isBlank()
                ? "FXCS-" + (repo.count() + 1) : req.measureNo());
        m.setTitle(req.title());
        m.setDescription(req.description());
        m.setOwner(req.owner());
        m.setOwnerDept(req.ownerDept());
        m.setDueDate(req.dueDate());
        m.setStatus(req.status() == null || req.status().isBlank() ? "待执行" : req.status());
        m.setCompletedDate(req.completedDate());
        m.setResult(req.result());
        m.setCreatedAt(Instant.now());
        return ApiResp.ok(repo.save(m));
    }

    @PatchMapping("/{id}")
    @Transactional
    public ApiResp<LegalRiskMeasure> update(@PathVariable Long id, @RequestBody MeasureRequest req) {
        LegalRiskMeasure m = repo.findById(id)
                .orElseThrow(() -> new NotFoundException("风险应对措施不存在: " + id));
        if (req.title() != null && !req.title().isBlank()) m.setTitle(req.title());
        if (req.description() != null) m.setDescription(req.description());
        if (req.owner() != null) m.setOwner(req.owner());
        if (req.ownerDept() != null) m.setOwnerDept(req.ownerDept());
        if (req.dueDate() != null && !req.dueDate().isBlank()) m.setDueDate(req.dueDate());
        if (req.status() != null && !req.status().isBlank()) m.setStatus(req.status());
        if (req.completedDate() != null) m.setCompletedDate(req.completedDate());
        if (req.result() != null) m.setResult(req.result());
        return ApiResp.ok(repo.save(m));
    }

    @DeleteMapping("/{id}")
    @Transactional
    public ApiResp<Void> delete(@PathVariable Long id) {
        if (!repo.existsById(id)) {
            throw new NotFoundException("风险应对措施不存在: " + id);
        }
        repo.deleteById(id);
        return ApiResp.ok(null);
    }

    // ---------- 状态流转 ----------

    @PostMapping("/{id}/start")
    @Transactional
    public ApiResp<LegalRiskMeasure> start(@PathVariable Long id) {
        LegalRiskMeasure m = repo.findById(id)
                .orElseThrow(() -> new NotFoundException("风险应对措施不存在: " + id));
        if (!"待执行".equals(m.getStatus())) {
            throw new ApiException(409, "只有「待执行」状态的措施可以启动");
        }
        m.setStatus("执行中");
        return ApiResp.ok(repo.save(m));
    }

    public record CompleteRequest(String result) {
    }

    @PostMapping("/{id}/complete")
    @Transactional
    public ApiResp<LegalRiskMeasure> complete(@PathVariable Long id, @RequestBody CompleteRequest req) {
        LegalRiskMeasure m = repo.findById(id)
                .orElseThrow(() -> new NotFoundException("风险应对措施不存在: " + id));
        if ("已完成".equals(m.getStatus()) || "已取消".equals(m.getStatus())) {
            throw new ApiException(409, "该措施已处于终态，无法再次标记完成");
        }
        m.setStatus("已完成");
        m.setCompletedDate(LocalDate.now().toString());
        if (req.result() != null && !req.result().isBlank()) {
            m.setResult(req.result());
        }
        return ApiResp.ok(repo.save(m));
    }

    @PostMapping("/{id}/cancel")
    @Transactional
    public ApiResp<LegalRiskMeasure> cancel(@PathVariable Long id) {
        LegalRiskMeasure m = repo.findById(id)
                .orElseThrow(() -> new NotFoundException("风险应对措施不存在: " + id));
        if ("已完成".equals(m.getStatus())) {
            throw new ApiException(409, "已完成的措施不可取消");
        }
        m.setStatus("已取消");
        return ApiResp.ok(repo.save(m));
    }

    // ---------- 逾期预警 ----------

    /**
     * 返回 dueDate < 今日 且 status 不是「已完成」/「已取消」 的超期措施。
     * 供法务每日检查应对措施跟踪进度。
     */
    @GetMapping("/overdue")
    public ApiResp<List<LegalRiskMeasure>> overdue() {
        String today = LocalDate.now().toString();
        List<LegalRiskMeasure> all = repo.findAll();
        return ApiResp.ok(all.stream()
                .filter(m -> m.getDueDate() != null
                        && m.getDueDate().compareTo(today) < 0
                        && !CLOSED_STATUSES.contains(m.getStatus()))
                .toList());
    }

    // ---------- 统计 ----------

    public record MeasureStats(int total, int pending, int inProgress, int completed, int cancelled,
                               int overdueCount, Map<String, Integer> byDept) {
    }

    @GetMapping("/stats")
    public ApiResp<MeasureStats> stats() {
        String today = LocalDate.now().toString();
        List<LegalRiskMeasure> all = repo.findAll();
        int pending = 0, inProgress = 0, completed = 0, cancelled = 0, overdueCount = 0;
        Map<String, Integer> byDept = new LinkedHashMap<>();
        for (LegalRiskMeasure m : all) {
            String s = m.getStatus() == null ? "待执行" : m.getStatus();
            if ("待执行".equals(s)) pending++;
            else if ("执行中".equals(s)) inProgress++;
            else if ("已完成".equals(s)) completed++;
            else if ("已取消".equals(s)) cancelled++;
            if (m.getDueDate() != null && m.getDueDate().compareTo(today) < 0
                    && !CLOSED_STATUSES.contains(s)) {
                overdueCount++;
            }
            byDept.merge(m.getOwnerDept() == null ? "未分配" : m.getOwnerDept(), 1, Integer::sum);
        }
        return ApiResp.ok(new MeasureStats(all.size(), pending, inProgress, completed, cancelled, overdueCount, byDept));
    }
}