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.LabStocktake;
import com.kaidi.oa.domain.LabStocktakeLine;
import com.kaidi.oa.domain.Reagent;
import com.kaidi.oa.repository.LabStocktakeLineRepository;
import com.kaidi.oa.repository.LabStocktakeRepository;
import com.kaidi.oa.repository.ReagentRepository;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.GetMapping;
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.List;

/**
 * 实验室·库存盘点（试剂耗材与库存管理 §4 深化）。周期/移动端扫码盘点，自动生成盘盈盘亏报表。
 *
 * - create   建盘点单：按 scope 把当前试剂账面库存快照成盘点明细行（盘点中）；
 * - count     逐行录实盘数（支持扫码 byScan），自动算差异与盘盈/盘亏结果；
 * - finish    完成：汇总盘盈/盘亏项数，可选 apply 把账面库存调整为实盘数（应用盘点结果）；
 * - lines     盘点明细（盘盈盘亏报表数据源）。
 *
 * 写口默认受 default-deny(ADMIN/APPROVER) 保护。
 */
@RestController
@RequestMapping("/api/oa/lab-stocktakes")
public class LabStocktakeController {

    private final LabStocktakeRepository stRepo;
    private final LabStocktakeLineRepository lineRepo;
    private final ReagentRepository reagentRepo;

    public LabStocktakeController(LabStocktakeRepository stRepo,
                                  LabStocktakeLineRepository lineRepo,
                                  ReagentRepository reagentRepo) {
        this.stRepo = stRepo;
        this.lineRepo = lineRepo;
        this.reagentRepo = reagentRepo;
    }

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

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

    @GetMapping("/{id}/lines")
    public ApiResp<List<LabStocktakeLine>> lines(@PathVariable Long id) {
        must(id);
        return ApiResp.ok(lineRepo.findByStocktakeIdOrderByIdAsc(id));
    }

    public record CreateRequest(String scope, String operator, String stocktakeDate) {
    }

    /** 建盘点单并快照账面库存为明细行（scope=某分类 则只盘该分类，否则盘全部）。 */
    @PostMapping
    @Transactional
    public ApiResp<LabStocktake> create(@RequestBody CreateRequest req) {
        LabStocktake st = new LabStocktake();
        st.setStocktakeNo("PD-" + (stRepo.count() + 1));
        st.setScope(req.scope() == null || req.scope().isBlank() ? "全部" : req.scope());
        st.setOperator(req.operator());
        st.setStocktakeDate(req.stocktakeDate() == null || req.stocktakeDate().isBlank()
                ? LocalDate.now().toString() : req.stocktakeDate());
        st.setStatus("盘点中");
        st.setProfitCount(0);
        st.setLossCount(0);
        st.setApplied(false);
        st.setCreatedAt(Instant.now());
        LabStocktake saved = stRepo.save(st);

        List<Reagent> scope = ("全部".equals(saved.getScope()))
                ? reagentRepo.findAll() : reagentRepo.findByCategory(saved.getScope());
        for (Reagent r : scope) {
            LabStocktakeLine ln = new LabStocktakeLine();
            ln.setStocktakeId(saved.getId());
            ln.setReagentId(r.getId());
            ln.setReagentCode(r.getCode());
            ln.setReagentName(r.getName());
            ln.setBookQty(nz(r.getStockQty()));
            ln.setResult("未盘");
            ln.setByScan(false);
            lineRepo.save(ln);
        }
        return ApiResp.ok(saved);
    }

    public record CountRequest(Long lineId, Long reagentId, Double countedQty, Boolean byScan) {
    }

    /** 录实盘数：按 lineId 或扫码 reagentId 定位行，写实盘数并算差异/结果。 */
    @PostMapping("/{id}/count")
    @Transactional
    public ApiResp<LabStocktakeLine> count(@PathVariable Long id, @RequestBody CountRequest req) {
        LabStocktake st = must(id);
        if (!"盘点中".equals(st.getStatus())) {
            throw new ApiException(409, "盘点已完成，不能再录");
        }
        LabStocktakeLine ln = null;
        if (req.lineId() != null) {
            ln = lineRepo.findById(req.lineId()).orElse(null);
        } else if (req.reagentId() != null) {
            ln = lineRepo.findByStocktakeIdOrderByIdAsc(id).stream()
                    .filter(x -> req.reagentId().equals(x.getReagentId()))
                    .findFirst().orElse(null);
        }
        if (ln == null || !id.equals(ln.getStocktakeId())) {
            throw new NotFoundException("盘点明细行不存在");
        }
        if (req.countedQty() == null || req.countedQty() < 0) {
            throw new ApiException(400, "实盘数(countedQty) 必须 >= 0");
        }
        ln.setCountedQty(req.countedQty());
        double diff = req.countedQty() - nz(ln.getBookQty());
        ln.setDiff(round2(diff));
        ln.setResult(diff > 1e-9 ? "盘盈" : (diff < -1e-9 ? "盘亏" : "一致"));
        ln.setByScan(Boolean.TRUE.equals(req.byScan()));
        return ApiResp.ok(lineRepo.save(ln));
    }

    public record FinishRequest(boolean apply) {
    }

    /** 完成盘点：汇总盘盈/盘亏项数；apply=true 时把账面库存调整为实盘数。 */
    @PostMapping("/{id}/finish")
    @Transactional
    public ApiResp<LabStocktake> finish(@PathVariable Long id, @RequestBody FinishRequest req) {
        LabStocktake st = must(id);
        if ("已完成".equals(st.getStatus())) {
            throw new ApiException(409, "盘点已完成");
        }
        int profit = 0;
        int loss = 0;
        for (LabStocktakeLine ln : lineRepo.findByStocktakeIdOrderByIdAsc(id)) {
            if ("盘盈".equals(ln.getResult())) profit++;
            if ("盘亏".equals(ln.getResult())) loss++;
            if (req.apply() && ln.getCountedQty() != null
                    && ("盘盈".equals(ln.getResult()) || "盘亏".equals(ln.getResult()))) {
                reagentRepo.findById(ln.getReagentId()).ifPresent(r -> {
                    r.setStockQty(ln.getCountedQty());
                    reagentRepo.save(r);
                });
            }
        }
        st.setProfitCount(profit);
        st.setLossCount(loss);
        st.setApplied(req.apply());
        st.setStatus("已完成");
        return ApiResp.ok(stRepo.save(st));
    }

    // ---------- helpers ----------

    private LabStocktake must(Long id) {
        return stRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("stocktake not found: " + id));
    }

    private static double nz(Double v) {
        return v == null ? 0.0 : v;
    }

    private static double round2(double v) {
        return Math.round(v * 100.0) / 100.0;
    }
}