/**
 * 家书 FamilyBook · 在线阅读浮层（鸿蒙端，工单 #28）
 *
 * 对应网页版 `templates/books/read.php`：章节列表 + 单章正文。
 *
 * 用户 2026-10-28 原话「鸿蒙端对齐网页端」。原来端上只能看进度数字，
 * 在线读、上传解析、笔记导入都在网页端。这个浮层把「在线读」补上。
 *
 * ⚠️ 章节正文走 `GET /books/<id>/chapter?seq=N`（服务端 `Book::chapter`），
 *    一次只读一章（正文很长，全量拉会爆内存）。
 */

import { FbColors, FbMetric, FB_MASK } from '../common/Theme';
import { FbSheetRing } from './FbSheetRing';
import { FbSheetClose } from './FbSheetClose';
import { FB_TOKEN_STORE } from '../data/FbTokenStore';
import { FbApiResult } from '../data/FbHttp';
import { fetchBookChapters, fetchBookChapter } from '../data/FbBookRepo';

/** 服务端 `Book::chapters()` 的一行（id/seq/title/words） */
interface FbChapterRow {
  id: number;
  seq: number;
  title: string;
  words: number;
}

interface RawChapter {
  id?: number; seq?: number; title?: string | null; words?: number;
}

@ComponentV2
export struct FbBookReadSheet {
  @Param bookId: number = 0;
  @Param bookTitle: string = '';
  @Param accent: string = '#6B5B95';

  @Event onClose: () => void = (): void => {};

  @Local chapters: FbChapterRow[] = [];
  @Local loadingList: boolean = true;
  @Local listNote: string = '';

  /** 正在读那一章 */
  @Local curSeq: number = 0;
  @Local curTitle: string = '';
  @Local curBody: string = '';
  @Local loadingChapter: boolean = false;
  @Local chapterNote: string = '';

  aboutToAppear(): void {
    this.loadChapters();
  }

  private async loadChapters(): Promise<void> {
    this.loadingList = true;
    this.listNote = '';
    const res: FbApiResult = await fetchBookChapters(FB_TOKEN_STORE.get(), this.bookId);
    this.loadingList = false;
    if (!res.ok) {
      this.listNote = res.error !== '' ? res.error : '章节列表没拉到。';
      return;
    }
    const out: FbChapterRow[] = [];
    try {
      const o: Record<string, Object> = JSON.parse(res.data) as Record<string, Object>;
      const items: Object | undefined = o['items'];
      const rows: RawChapter[] = (items !== undefined && items !== null)
        ? (items as RawChapter[]) : [];
      for (const c of rows) {
        out.push({
          id: c.id !== undefined ? c.id : 0,
          seq: c.seq !== undefined ? c.seq : 0,
          title: c.title !== undefined && c.title !== null ? c.title : '',
          words: c.words !== undefined ? c.words : 0,
        });
      }
    } catch (e) {
      // 解析失败当空列表
    }
    this.chapters = out;
  }

  private async openChapter(seq: number, title: string): Promise<void> {
    this.curSeq = seq;
    this.curTitle = title;
    this.loadingChapter = true;
    this.chapterNote = '';
    const res: FbApiResult = await fetchBookChapter(FB_TOKEN_STORE.get(), this.bookId, seq);
    this.loadingChapter = false;
    if (!res.ok) {
      this.chapterNote = res.error !== '' ? res.error : '这一章没读到。';
      return;
    }
    try {
      const o: Record<string, Object> = JSON.parse(res.data) as Record<string, Object>;
      const c: Object | undefined = o['content'];
      this.curBody = typeof c === 'string' ? c : '';
    } catch (e) {
      this.curBody = '';
      this.chapterNote = '正文解析失败。';
    }
  }

  build() {
    Stack({ alignContent: Alignment.Center }) {
      Column()
        .width('100%')
        .height('100%')
        .backgroundColor(FB_MASK)
        .onClick((): void => {
          this.onClose();
        })

      Column() {
        FbSheetRing({ radius: FbMetric.radius, ringColor: this.accent }) {
          Column({ space: 0 }) {
            // 标题栏
            Row({ space: 8 }) {
              Column({ space: 2 }) {
                Text(this.bookTitle !== '' ? this.bookTitle : '在线阅读')
                  .fontSize(FbMetric.fontTitle)
                  .fontWeight(FontWeight.Medium)
                  .fontColor(FbColors.ink)
                  .maxLines(1)
                Text(this.curSeq > 0 ? this.curTitle : (this.chapters.length.toString() + ' 章'))
                  .fontSize(FbMetric.fontTiny)
                  .fontColor(this.accent)
                  .maxLines(1)
              }
              .alignItems(HorizontalAlign.Start)
              .layoutWeight(1)
              .flexShrink(1)

              FbSheetClose({
                onClose: (): void => {
                  this.onClose();
                },
                color: this.accent
              })
            }
            .width('100%')
            .padding({ bottom: 8 })
            .alignItems(VerticalAlign.Center)

            if (this.listNote !== '') {
              Text(this.listNote)
                .fontSize(FbMetric.fontTiny)
                .fontColor(FbColors.red)
                .width('100%')
                .padding({ top: 6, bottom: 6 })
            }

            if (this.curSeq > 0) {
              // 正文态
              Column({ space: 8 }) {
                Row() {
                  Text('← 目录')
                    .fontSize(FbMetric.fontTiny)
                    .fontColor(this.accent)
                    .padding({ left: 8, right: 8, top: 5, bottom: 5 })
                    .onClick((): void => {
                      this.curSeq = 0;
                    })
                }
                .width('100%')

                if (this.loadingChapter) {
                  Text('正在取这一章…')
                    .fontSize(FbMetric.fontSmall)
                    .fontColor(FbColors.faint)
                    .width('100%')
                } else if (this.chapterNote !== '') {
                  Text(this.chapterNote)
                    .fontSize(FbMetric.fontTiny)
                    .fontColor(FbColors.red)
                    .width('100%')
                } else {
                  Scroll() {
                    Text(this.curBody)
                      .fontSize(16)
                      .lineHeight(26)
                      .fontColor(FbColors.ink)
                      .width('100%')
                  }
                  .constraintSize({ maxHeight: 520 })
                  .width('100%')
                  .scrollBar(BarState.Off)
                }
              }
              .width('100%')
              .alignItems(HorizontalAlign.Start)
            } else {
              // 目录态
              if (this.loadingList) {
                Text('正在取目录…')
                  .fontSize(FbMetric.fontSmall)
                  .fontColor(FbColors.faint)
                  .width('100%')
              } else if (this.chapters.length === 0) {
                Text(this.listNote !== '' ? this.listNote : '这本书还没有解析出章节（可能是 PDF，浏览器里看，或没上传文件）。')
                  .fontSize(FbMetric.fontSmall)
                  .fontColor(FbColors.faint)
                  .width('100%')
              } else {
                Scroll() {
                  Column({ space: 0 }) {
                    ForEach(this.chapters, (c: FbChapterRow) => {
                      Row({ space: 8 }) {
                        Column({ space: 2 }) {
                          Text(c.title !== '' ? c.title : ('第 ' + c.seq.toString() + ' 章'))
                            .fontSize(FbMetric.fontSmall)
                            .fontColor(FbColors.ink)
                            .maxLines(1)
                            .textOverflow({ overflow: TextOverflow.Ellipsis })
                          Text(c.words.toString() + ' 字')
                            .fontSize(10)
                            .fontColor(FbColors.faint)
                        }
                        .alignItems(HorizontalAlign.Start)
                        .layoutWeight(1)
                        Text('›')
                          .fontSize(FbMetric.fontBody)
                          .fontColor(FbColors.faint)
                      }
                      .width('100%')
                      .padding({ top: 10, bottom: 10 })
                      .onClick((): void => {
                        this.openChapter(c.seq, c.title);
                      })
                    }, (c: FbChapterRow): string => 'ch_' + c.seq.toString())
                  }
                  .width('100%')
                  .alignItems(HorizontalAlign.Start)
                }
                .constraintSize({ maxHeight: 520 })
                .width('100%')
                .scrollBar(BarState.Off)
              }
            }
          }
          .width('100%')
          .padding({ left: 18, right: 18, top: 18, bottom: 18 })
          .alignItems(HorizontalAlign.Start)
        }
      }
      .width('92%')
    }
    .width('100%')
    .height('100%')
    .hitTestBehavior(HitTestMode.Transparent)
  }
}