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.Announcement;
import com.kaidi.oa.repository.AnnouncementRepository;
import org.springframework.web.bind.annotation.DeleteMapping;
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.PutMapping;
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;

/** News / announcements. category is one of 新闻 / 公告. */
@RestController
@RequestMapping("/api/oa/announcements")
public class AnnouncementController {

    private final AnnouncementRepository announcementRepo;

    public AnnouncementController(AnnouncementRepository announcementRepo) {
        this.announcementRepo = announcementRepo;
    }

    @GetMapping
    public ApiResp<List<Announcement>> list(
            @RequestParam(required = false) String category,
            @RequestParam(defaultValue = "0") int pageNo,
            @RequestParam(defaultValue = "200") int pageSize) {
        List<Announcement> list = (category == null || category.isBlank())
                ? announcementRepo.findAllByOrderByTopDescPublishedAtDesc()
                : announcementRepo.findByCategoryOrderByTopDescPublishedAtDesc(category);
        return ApiResp.ok(page(list, pageNo, pageSize));
    }

    /** 内存切片：pageNo 从 0 起；pageSize<=0 取默认 200、超过 500 截为 500，避免全表载入。 */
    private static final int DEFAULT_PAGE_SIZE = 200;
    private static final int MAX_PAGE_SIZE = 500;

    private static <T> List<T> page(List<T> list, int pageNo, int pageSize) {
        if (pageSize <= 0) {
            pageSize = DEFAULT_PAGE_SIZE;
        } else if (pageSize > MAX_PAGE_SIZE) {
            pageSize = MAX_PAGE_SIZE;
        }
        long fromL = (long) Math.max(0, pageNo) * pageSize;
        if (fromL >= list.size()) {
            return List.of();
        }
        int from = (int) fromL;
        return list.subList(from, Math.min(from + pageSize, list.size()));
    }

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

    public record CreateAnnouncementRequest(
            String category, String title, String content, String author, Boolean top, String publishRange) {
    }

    @PostMapping
    public ApiResp<Announcement> create(@RequestBody CreateAnnouncementRequest req) {
        if (req.title() == null || req.title().isBlank()) {
            throw new ApiException(400, "title is required");
        }
        Announcement a = new Announcement();
        a.setCategory(req.category() == null ? "公告" : req.category());
        a.setTitle(req.title());
        a.setContent(HtmlSanitizer.sanitize(req.content()));
        a.setAuthor(req.author());
        a.setTop(Boolean.TRUE.equals(req.top()));
        a.setPublishRange(req.publishRange());
        a.setPublishedAt(Instant.now());
        return ApiResp.ok(announcementRepo.save(a));
    }

    public record UpdateAnnouncementRequest(String title, String content, String category, String publishRange) {
    }

    /** PUT /{id} -> 编辑已发布的新闻/公告 (title/content/category/publishRange)。 */
    @PutMapping("/{id}")
    public ApiResp<Announcement> update(@PathVariable Long id, @RequestBody UpdateAnnouncementRequest req) {
        Announcement a = announcementRepo.findById(id)
                .orElseThrow(() -> new NotFoundException("announcement not found: " + id));
        if (req.title() != null) {
            if (req.title().isBlank()) {
                throw new ApiException(400, "标题不能为空");
            }
            a.setTitle(req.title().trim());
        }
        if (req.content() != null) a.setContent(HtmlSanitizer.sanitize(req.content()));
        if (req.category() != null) a.setCategory(req.category());
        if (req.publishRange() != null) a.setPublishRange(req.publishRange());
        return ApiResp.ok(announcementRepo.save(a));
    }

    /** DELETE /{id} -> 撤回新闻/公告。 */
    @DeleteMapping("/{id}")
    public ApiResp<Void> delete(@PathVariable Long id) {
        if (!announcementRepo.existsById(id)) {
            throw new NotFoundException("announcement not found: " + id);
        }
        announcementRepo.deleteById(id);
        return ApiResp.ok(null);
    }
}