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.CultureMaterial;
import com.kaidi.oa.domain.CultureMaterialDownload;
import com.kaidi.oa.repository.CultureMaterialDownloadRepository;
import com.kaidi.oa.repository.CultureMaterialRepository;
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.util.List;

/**
 * 员工宣传素材授权下载追踪（品牌推广部·宣传部·模块7 缺口）。
 *
 * 补完需求：CultureMaterial.fileUrls 原仅存 URL 字符串，无版本授权下载追踪。
 * 本控制器为每次"员工申请下载"建立授权记录，宣传部可审批（已授权/已拒绝），
 * 审批通过后员工确认下载时记录 downloadAt 时间戳，形成完整的分发留痕。
 *
 * 已通过素材（CultureMaterial.status=已通过）可直接申请，自动置为「已授权」；
 * 受控素材（如草稿/退回）需人工审批，防止未定稿素材外流。
 */
@RestController
@RequestMapping("/api/oa/culture-material-downloads")
public class CultureMaterialDownloadController {

    private final CultureMaterialDownloadRepository dlRepo;
    private final CultureMaterialRepository matRepo;

    public CultureMaterialDownloadController(CultureMaterialDownloadRepository dlRepo,
            CultureMaterialRepository matRepo) {
        this.dlRepo = dlRepo;
        this.matRepo = matRepo;
    }

    @GetMapping
    public ApiResp<List<CultureMaterialDownload>> list(
            @RequestParam(required = false) Long materialId,
            @RequestParam(required = false) String downloader,
            @RequestParam(required = false) String authStatus) {
        if (materialId != null) {
            return ApiResp.ok(dlRepo.findByMaterialId(materialId));
        }
        if (downloader != null && !downloader.isBlank()) {
            return ApiResp.ok(dlRepo.findByDownloader(downloader));
        }
        if (authStatus != null && !authStatus.isBlank()) {
            return ApiResp.ok(dlRepo.findByAuthStatus(authStatus));
        }
        return ApiResp.ok(dlRepo.findAll());
    }

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

    public record DownloadRequest(
            Long materialId, String downloader, String downloaderDept,
            String purpose, String version) {
    }

    /**
     * 申请下载素材。
     * - 素材为「已通过」状态时，自动置「已授权」，员工直接可下载；
     * - 其他状态需宣传部手工授权（置「申请中」等待审批）。
     */
    @PostMapping
    @Transactional
    public ApiResp<CultureMaterialDownload> apply(@RequestBody DownloadRequest req) {
        if (req.materialId() == null) {
            throw new ApiException(400, "materialId 不能为空");
        }
        if (req.downloader() == null || req.downloader().isBlank()) {
            throw new ApiException(400, "申请人(downloader) 不能为空");
        }
        CultureMaterial mat = matRepo.findById(req.materialId())
                .orElseThrow(() -> new NotFoundException("素材不存在：" + req.materialId()));

        CultureMaterialDownload dl = new CultureMaterialDownload();
        dl.setMaterialId(req.materialId());
        dl.setMaterialTitle(mat.getTitle());
        dl.setDownloader(req.downloader());
        dl.setDownloaderDept(req.downloaderDept());
        dl.setPurpose(req.purpose() == null ? "内部展示" : req.purpose());
        dl.setVersion(req.version() == null ? "v1.0" : req.version());
        dl.setCreatedAt(Instant.now());

        // 已通过素材自动授权；否则人工审批
        if ("已通过".equals(mat.getStatus())) {
            dl.setAuthStatus("已授权");
            dl.setAuthorizedAt(Instant.now());
            dl.setAuthorizedBy("系统自动");
        } else {
            dl.setAuthStatus("申请中");
        }
        return ApiResp.ok(dlRepo.save(dl));
    }

    public record AuthRequest(String authorizedBy, String authComment, boolean approved) {
    }

    /** 宣传部审批：申请中 → 已授权 / 已拒绝。 */
    @PostMapping("/{id}/authorize")
    @Transactional
    public ApiResp<CultureMaterialDownload> authorize(@PathVariable Long id,
            @RequestBody AuthRequest req) {
        CultureMaterialDownload dl = require(id);
        if (!"申请中".equals(dl.getAuthStatus())) {
            throw new ApiException(409, "仅「申请中」可审批，当前「" + dl.getAuthStatus() + "」");
        }
        if (req.authorizedBy() == null || req.authorizedBy().isBlank()) {
            throw new ApiException(400, "授权人(authorizedBy) 不能为空");
        }
        dl.setAuthorizedBy(req.authorizedBy());
        dl.setAuthComment(req.authComment());
        dl.setAuthStatus(req.approved() ? "已授权" : "已拒绝");
        if (req.approved()) {
            dl.setAuthorizedAt(Instant.now());
        }
        return ApiResp.ok(dlRepo.save(dl));
    }

    /** 确认下载：已授权 → 记录 downloadAt 时间戳（员工实际点击下载时调用）。 */
    @PostMapping("/{id}/confirm-download")
    @Transactional
    public ApiResp<CultureMaterialDownload> confirmDownload(@PathVariable Long id) {
        CultureMaterialDownload dl = require(id);
        if (!"已授权".equals(dl.getAuthStatus())) {
            throw new ApiException(409, "仅已授权记录可确认下载，当前「" + dl.getAuthStatus() + "」");
        }
        if (dl.getDownloadAt() != null) {
            throw new ApiException(409, "该授权记录已确认下载，请勿重复");
        }
        dl.setDownloadAt(Instant.now());
        return ApiResp.ok(dlRepo.save(dl));
    }

    /** 素材下载统计（按素材汇总申请量/已授权量/实际下载量）。 */
    public record DownloadStat(Long materialId, String materialTitle,
            long applied, long authorized, long downloaded) {
    }

    @GetMapping("/stats")
    public ApiResp<List<DownloadStat>> stats() {
        List<CultureMaterialDownload> all = dlRepo.findAll();
        java.util.Map<Long, DownloadStat> m = new java.util.LinkedHashMap<>();
        for (CultureMaterialDownload dl : all) {
            Long mid = dl.getMaterialId();
            DownloadStat prev = m.getOrDefault(mid,
                    new DownloadStat(mid, dl.getMaterialTitle(), 0, 0, 0));
            long app = prev.applied() + 1;
            long auth = prev.authorized() + ("已授权".equals(dl.getAuthStatus()) ? 1 : 0);
            long done = prev.downloaded() + (dl.getDownloadAt() != null ? 1 : 0);
            m.put(mid, new DownloadStat(mid, dl.getMaterialTitle(), app, auth, done));
        }
        return ApiResp.ok(new java.util.ArrayList<>(m.values()));
    }

    private CultureMaterialDownload require(Long id) {
        return dlRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("下载记录不存在：" + id));
    }
}