package com.kaidi.oa.web;

import com.kaidi.oa.common.ApiException;
import com.kaidi.oa.common.ApiResp;
import com.kaidi.oa.common.HtmlSanitizer;
import com.kaidi.oa.common.NotFoundException;
import com.kaidi.oa.domain.Blog;
import com.kaidi.oa.domain.SysUser;
import com.kaidi.oa.repository.BlogRepository;
import com.kaidi.oa.service.AuthorizationService;
import jakarta.annotation.PostConstruct;
import jakarta.servlet.http.HttpServletRequest;
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.RestController;

import java.time.LocalDate;
import java.util.List;

/**
 * 我的博客 (知识社区). Self-seeds 12 demo posts on first run (when the table is
 * empty) so the page stays populated; create/update persist real posts.
 */
@RestController
@RequestMapping("/api/oa/blogs")
public class BlogController {

    private final BlogRepository blogRepo;
    private final CurrentUserResolver currentUser;
    private final AuthorizationService authz;

    public BlogController(BlogRepository blogRepo, CurrentUserResolver currentUser,
                          AuthorizationService authz) {
        this.blogRepo = blogRepo;
        this.currentUser = currentUser;
        this.authz = authz;
    }

    /**
     * 对象级写授权：仅博客作者(按稳定 authorId，空回退 author 名)本人或 ADMIN 可改/下架，
     * 杜绝任意登录用户按 id 枚举篡改/下架他人博客（BOLA/IDOR）。
     */
    private void assertAuthorOrAdmin(Blog b, HttpServletRequest http) {
        SysUser su = currentUser.resolve(http);
        if (!authz.isAdmin(su) && !authz.isOwner(su, b.getAuthorId(), b.getAuthor())) {
            throw new ApiException(403, "无权操作：仅博客作者本人或管理员可修改/下架该博客");
        }
    }

    private static final String[] PEOPLE = {
            "张伟", "李娜", "王芳", "刘洋", "陈静", "赵强", "杨敏", "黄磊", "周婷", "吴昊"
    };
    private static final String[] CATEGORIES = {
            "工作随笔", "技术分享", "项目复盘", "读书笔记", "管理心得"
    };
    private static final String[] STATUS = {"已发布", "草稿", "审核中", "已下架"};
    private static final String[] TITLES = {
            "从一次线上故障谈系统稳定性建设",
            "OA流程引擎设计的几点思考",
            "我在工程部的第一个季度复盘",
            "读《卓有成效的管理者》有感",
            "如何写一份让人愿意读的会议纪要",
            "团队协作中的沟通成本与解法",
            "一次跨部门项目的协同实践",
            "数据可视化让汇报更有说服力",
            "远程办公半年的得与失",
            "新人快速融入团队的五个建议",
            "低代码平台落地的踩坑记录",
            "关于知识沉淀这件小事"
    };
    private static final String[] TAG_POOL = {
            "稳定性", "架构", "复盘", "管理", "协作", "效率", "成长", "工具", "方法论", "随笔"
    };

    private static <T> T pick(T[] arr, int i) {
        return arr[((i % arr.length) + arr.length) % arr.length];
    }

    @PostConstruct
    void seedIfEmpty() {
        if (blogRepo.count() > 0) {
            return;
        }
        LocalDate base = LocalDate.of(2026, 6, 10);
        for (int i = 0; i < 12; i++) {
            Blog b = new Blog();
            b.setTitle(pick(TITLES, i));
            b.setSummary("记录工作与学习中的思考与实践，希望对同事们有所帮助。本文从实际案例出发，梳理了相关方法与心得，欢迎在评论区交流。");
            b.setBody("在实际工作中，我们经常会遇到各种各样的问题。本文结合具体案例，分享我的一些思考与做法。\n一、背景与问题。二、分析与思路。三、落地与效果。四、复盘与改进。\n欢迎大家在评论区交流，也欢迎收藏本文以备查阅。");
            b.setAuthor(pick(PEOPLE, i));
            b.setCategory(pick(CATEGORIES, i));
            b.setStatusId(pick(STATUS, i));
            b.setDate(base.minusDays(i * 2L).toString());
            b.setViews(320 - i * 18);
            b.setComments(24 - i);
            b.setLikes(86 - i * 5);
            b.setCover(i % 3 == 0);
            b.setTags(pick(TAG_POOL, i) + "," + pick(TAG_POOL, i + 4));
            blogRepo.save(b);
        }
    }

    @GetMapping
    public ApiResp<List<Blog>> list() {
        return ApiResp.ok(blogRepo.findAll());
    }

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

    public record CreateBlogRequest(
            String title, String summary, String body, String author,
            String category, String statusId, String tags) {
    }

    @PostMapping
    public ApiResp<Blog> create(@RequestBody CreateBlogRequest req, HttpServletRequest http) {
        if (req.title() == null || req.title().isBlank()) {
            throw new ApiException(400, "title is required");
        }
        Blog b = new Blog();
        b.setTitle(req.title().trim());
        b.setSummary(HtmlSanitizer.sanitize(req.summary()));
        b.setBody(HtmlSanitizer.sanitize(req.body()));
        // 作者署名服务端定调：已登录者强制记为本人(authorId=稳定 userId + author=displayName 展示)，
        // 未登录回退前端 author（demo 兼容），杜绝冒充他人为作者（批量赋值）。
        SysUser su = currentUser.resolve(http);
        String label = currentUser.resolveLabel(http);
        boolean anon = CurrentUserResolver.DEMO_USER_LABEL.equals(label);
        b.setAuthor(anon ? (req.author() == null || req.author().isBlank() ? "张伟" : req.author()) : label);
        b.setAuthorId(su != null ? su.getId() : null);
        b.setCategory(req.category() == null ? "工作随笔" : req.category());
        b.setStatusId(req.statusId() == null ? "已发布" : req.statusId());
        b.setTags(req.tags() == null ? "" : req.tags());
        b.setDate(LocalDate.of(2026, 6, 11).toString());
        b.setViews(0);
        b.setComments(0);
        b.setLikes(0);
        b.setCover(false);
        return ApiResp.ok(blogRepo.save(b));
    }

    public record UpdateBlogRequest(String title, String summary, String body, String category, String statusId, String tags) {
    }

    @PatchMapping("/{id}")
    public ApiResp<Blog> update(@PathVariable Long id, @RequestBody UpdateBlogRequest req,
                                HttpServletRequest http) {
        Blog b = blogRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("blog not found: " + id));
        assertAuthorOrAdmin(b, http);
        if (req.title() != null) b.setTitle(req.title());
        if (req.summary() != null) b.setSummary(HtmlSanitizer.sanitize(req.summary()));
        if (req.body() != null) b.setBody(HtmlSanitizer.sanitize(req.body()));
        if (req.category() != null) b.setCategory(req.category());
        if (req.statusId() != null) b.setStatusId(req.statusId());
        if (req.tags() != null) b.setTags(req.tags());
        return ApiResp.ok(blogRepo.save(b));
    }
}