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.LegalConsult;
import com.kaidi.oa.domain.LegalKnowledge;
import com.kaidi.oa.repository.LegalConsultRepository;
import com.kaidi.oa.repository.LegalKnowledgeRepository;
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;

/**
 * 法务合规·法律咨询与内部服务。业务部门提交法律咨询工单，法务分派承办人、回复法律意见、留档闭环。
 * 工单 CRUD + 分派(assign，状态→处理中) + 答复(reply，回填法律意见并置已答复) + 关闭。
 *
 * 含部门法律意见等内部信息，读口已登记进 SENSITIVE_READ_PREFIXES；写口受 default-deny 保护。
 */
@RestController
@RequestMapping("/api/oa/legal-consults")
public class LegalConsultController {

    private final LegalConsultRepository repo;
    private final LegalKnowledgeRepository knowledgeRepo;

    public LegalConsultController(LegalConsultRepository repo, LegalKnowledgeRepository knowledgeRepo) {
        this.repo = repo;
        this.knowledgeRepo = knowledgeRepo;
    }

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

    @GetMapping("/{id}")
    public ApiResp<LegalConsult> get(@PathVariable Long id) {
        return ApiResp.ok(repo.findById(id)
                .orElseThrow(() -> new NotFoundException("legal consult not found: " + id)));
    }

    public record ConsultRequest(
            String code, String subject, String detail, String requestDept, String requester,
            String urgency, String assignee, String legalOpinion, String status) {
    }

    @PostMapping
    public ApiResp<LegalConsult> create(@RequestBody ConsultRequest req) {
        if (req.subject() == null || req.subject().isBlank()) {
            throw new ApiException(400, "咨询事项(subject) 不能为空");
        }
        LegalConsult c = new LegalConsult();
        c.setCode(req.code() == null || req.code().isBlank()
                ? "FLZX-" + (repo.count() + 1) : req.code());
        c.setSubject(req.subject());
        c.setDetail(req.detail());
        c.setRequestDept(req.requestDept());
        c.setRequester(req.requester());
        c.setUrgency(req.urgency() == null || req.urgency().isBlank() ? "普通" : req.urgency());
        c.setAssignee(req.assignee());
        c.setLegalOpinion(req.legalOpinion());
        c.setStatus(req.status() == null || req.status().isBlank()
                ? (req.assignee() == null || req.assignee().isBlank() ? "待受理" : "处理中")
                : req.status());
        c.setCreatedAt(Instant.now());
        return ApiResp.ok(repo.save(c));
    }

    @PatchMapping("/{id}")
    public ApiResp<LegalConsult> update(@PathVariable Long id, @RequestBody ConsultRequest req) {
        LegalConsult c = repo.findById(id)
                .orElseThrow(() -> new NotFoundException("legal consult not found: " + id));
        if (req.subject() != null && !req.subject().isBlank()) c.setSubject(req.subject());
        if (req.detail() != null) c.setDetail(req.detail());
        if (req.requestDept() != null) c.setRequestDept(req.requestDept());
        if (req.requester() != null) c.setRequester(req.requester());
        if (req.urgency() != null && !req.urgency().isBlank()) c.setUrgency(req.urgency());
        if (req.assignee() != null) c.setAssignee(req.assignee());
        if (req.legalOpinion() != null) c.setLegalOpinion(req.legalOpinion());
        if (req.status() != null && !req.status().isBlank()) c.setStatus(req.status());
        return ApiResp.ok(repo.save(c));
    }

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

    // ---------- 分派承办法务 ----------

    public record AssignRequest(String assignee) {
    }

    /**
     * 分派工单给承办法务：回填 assignee，状态从「待受理」推进到「处理中」。
     */
    @PostMapping("/{id}/assign")
    public ApiResp<LegalConsult> assign(@PathVariable Long id, @RequestBody AssignRequest req) {
        LegalConsult c = repo.findById(id)
                .orElseThrow(() -> new NotFoundException("legal consult not found: " + id));
        if (req.assignee() == null || req.assignee().isBlank()) {
            throw new ApiException(400, "承办法务(assignee) 不能为空");
        }
        c.setAssignee(req.assignee());
        if ("待受理".equals(c.getStatus()) || c.getStatus() == null || c.getStatus().isBlank()) {
            c.setStatus("处理中");
        }
        return ApiResp.ok(repo.save(c));
    }

    // ---------- 答复法律意见 ----------

    public record ReplyRequest(String legalOpinion) {
    }

    /**
     * 答复法律意见：回填法律意见与答复日，状态置「已答复」。
     */
    @PostMapping("/{id}/reply")
    public ApiResp<LegalConsult> reply(@PathVariable Long id, @RequestBody ReplyRequest req) {
        LegalConsult c = repo.findById(id)
                .orElseThrow(() -> new NotFoundException("legal consult not found: " + id));
        if (req.legalOpinion() == null || req.legalOpinion().isBlank()) {
            throw new ApiException(400, "法律意见(legalOpinion) 不能为空");
        }
        c.setLegalOpinion(req.legalOpinion());
        c.setStatus("已答复");
        c.setRepliedDate(LocalDate.now().toString());
        return ApiResp.ok(repo.save(c));
    }

    // ---------- 知识库自动解答（常见问题 FAQ 检索） ----------

    public record AutoAnswerResult(boolean matched, List<KnowledgeHit> hits) {
    }

    public record KnowledgeHit(Long id, String title, String category, String bizScene,
                               String contentPreview) {
    }

    /**
     * 常见问题知识库自动解答：将咨询事项 subject + keyword 在法务知识库中做模糊匹配，
     * 返回最多 5 条相关知识条目，业务部门可先查阅后再决定是否正式提交工单。
     * 无法匹配时返回 matched=false，提示需人工受理。
     */
    @GetMapping("/auto-answer")
    public ApiResp<AutoAnswerResult> autoAnswer(@RequestParam String q) {
        if (q == null || q.isBlank()) {
            throw new ApiException(400, "检索词(q) 不能为空");
        }
        String kw = q.trim();
        // 标题命中 + 关键词命中，去重合并，最多返回 5 条
        List<LegalKnowledge> byTitle = knowledgeRepo.findByTitleContaining(kw);
        List<LegalKnowledge> byKw = knowledgeRepo.findByKeywordsContaining(kw);
        List<LegalKnowledge> merged = new ArrayList<>(byTitle);
        for (LegalKnowledge k : byKw) {
            if (merged.stream().noneMatch(m -> m.getId().equals(k.getId()))) {
                merged.add(k);
            }
        }
        List<KnowledgeHit> hits = merged.stream().limit(5).map(k -> new KnowledgeHit(
                k.getId(), k.getTitle(), k.getCategory(), k.getBizScene(),
                k.getContent() == null ? "" :
                        (k.getContent().length() > 120 ? k.getContent().substring(0, 120) + "…" : k.getContent())
        )).toList();
        return ApiResp.ok(new AutoAnswerResult(!hits.isEmpty(), hits));
    }
}