/**
 * 家书 FamilyBook · 财务模块（鸿蒙端）
 *
 * 对应 Web 端 `templates/ledger/index.php`。Web 端的结构（用户明确要求过的）：
 *   「上面是概览，下面就是具体账目…新建账目和设置都在右侧；
 *     每个账目的金额变化与总金额变化，在账本列表上面画出折线图。」
 *
 * 端上保留这个层次：
 *   ① 账本横条（多本账可横向切换）
 *   ② 概览卡：净资产大字 + 资产/负债分列（折线图位置留给第二轮，需要图表能力）
 *   ③ 账目表：按类别分组，每行带「盘点」入口
 *
 * ⚠️ 金额全程以**分**参与计算（`Ledger` 那套约定），显示时才转成元；
 *    任何地方都不要拿「元」去加总 —— 浮点误差会越滚越大。
 */

import { FbColors, FbMetric } from '../../common/Theme';
import { FbAppState, fbAppState } from '../../common/Store';
import { FbGroup, FbLedgerBook, FbLedgerEntry } from '../../model/Types';
import {
  FB_DEMO_LEDGER_BOOKS, FB_DEMO_LEDGER_ENTRIES, fbLedgerKindName, fbMoney
} from '../../model/DemoData';
import { FbEmptyBox, FbIconButton, FbPrimaryButton, FbTag } from '../../components/Widgets';

@ComponentV2
export struct FbLedgerPage {
  @Param app: FbAppState = fbAppState();

  /** 模块主题色（财务 = 橄榄绿） */
  private accent: string = '#5E7A3C';
  private books: FbLedgerBook[] = FB_DEMO_LEDGER_BOOKS;
  private entries: FbLedgerEntry[] = FB_DEMO_LEDGER_ENTRIES;
  /** 当前账本 id（0 = 用第一本） */
  @Local bookId: number = 0;

  build() {
    Column() {
      // ---- 页头 ----
      Row({ space: 8 }) {
        Column({ space: 2 }) {
          Text(this.currentBook().name)
            .fontSize(FbMetric.fontTitle)
            .fontWeight(FontWeight.Medium)
            .fontColor(FbColors.ink)
          Text(this.books.length.toString() + ' 本账 · '
            + this.currentBook().entryCount.toString() + ' 条账目')
            .fontSize(FbMetric.fontTiny)
            .fontColor(FbColors.faint)
        }
        .alignItems(HorizontalAlign.Start)
        .layoutWeight(1)

        FbPrimaryButton({
          label: '记一笔',
          bg: this.accent,
          icon: $r('app.media.fb_ic_plus')
        })
        FbIconButton({ icon: $r('app.media.fb_ic_gear'), tint: FbColors.muted })
      }
      .width('100%')
      .padding({ left: FbMetric.pagePad, right: FbMetric.pagePad, top: 12, bottom: 8 })
      .alignItems(VerticalAlign.Center)

      // ---- 账本切换（横向）----
      Scroll() {
        Row({ space: 8 }) {
          ForEach(this.books, (b: FbLedgerBook) => {
            Row({ space: 6 }) {
              Text(b.name)
                .fontSize(FbMetric.fontSmall)
                .fontColor(this.isCurrent(b.id) ? Color.White : FbColors.muted)
                .maxLines(1)
              if (b.myPerm !== 'owner') {
                FbTag({
                  text: b.myPerm === 'write' ? '可写' : '只读',
                  tone: this.isCurrent(b.id) ? 'brand' : 'muted'
                })
              }
            }
            .padding({ left: 12, right: 12, top: 7, bottom: 7 })
            .backgroundColor(this.isCurrent(b.id) ? this.accent : FbColors.surface)
            .borderRadius(FbMetric.radiusPill)
            .alignItems(VerticalAlign.Center)
            .onClick(() => {
              this.bookId = b.id;
            })
          }, (b: FbLedgerBook): string => 'bk_' + b.id.toString())
        }
        .padding({ left: FbMetric.pagePad, right: FbMetric.pagePad })
      }
      .scrollable(ScrollDirection.Horizontal)
      .scrollBar(BarState.Off)
      .width('100%')
      .padding({ bottom: 10 })

      Scroll() {
        Column({ space: 0 }) {

          // ---- 概览卡 ----
          Column({ space: 12 }) {
            Column({ space: 4 }) {
              Text('净资产')
                .fontSize(FbMetric.fontTiny)
                .fontColor(FbColors.muted)
              Text(fbMoney(this.netCent()))
                .fontSize(30)
                .fontWeight(FontWeight.Medium)
                .fontColor(FbColors.ink)
            }
            .alignItems(HorizontalAlign.Start)
            .width('100%')

            // 资产 / 负债分列
            Row({ space: 0 }) {
              Column({ space: 3 }) {
                Text('资产')
                  .fontSize(FbMetric.fontTiny)
                  .fontColor(FbColors.faint)
                Text(fbMoney(this.assetCent()))
                  .fontSize(FbMetric.fontBody)
                  .fontWeight(FontWeight.Medium)
                  .fontColor(FbColors.green)
              }
              .layoutWeight(1)
              .alignItems(HorizontalAlign.Start)

              Column({ space: 3 }) {
                Text('负债')
                  .fontSize(FbMetric.fontTiny)
                  .fontColor(FbColors.faint)
                Text(fbMoney(this.debtCent()))
                  .fontSize(FbMetric.fontBody)
                  .fontWeight(FontWeight.Medium)
                  .fontColor(FbColors.red)
              }
              .layoutWeight(1)
              .alignItems(HorizontalAlign.Start)
            }
            .width('100%')

            // 折线图占位（第二轮接图表能力后填）
            Column({ space: 4 }) {
              Row({ space: 6 }) {
                Image($r('app.media.fb_ic_chart'))
                  .width(13)
                  .height(13)
                  .renderMode(ImageRenderMode.Template)
                  .fillColor(FbColors.faint)
                Text('净资产变化（盘点成线）')
                  .fontSize(10)
                  .fontColor(FbColors.faint)
              }
              .alignItems(VerticalAlign.Center)

              Column()
                .width('100%')
                .height(56)
                .borderRadius(FbMetric.radiusS)
                .backgroundColor(FbColors.inputBg)
            }
            .width('100%')
            .alignItems(HorizontalAlign.Start)
          }
          .width('100%')
          .padding(FbMetric.cardPad)
          .backgroundColor(FbColors.surface)
          .borderRadius(FbMetric.radius)
          .margin({ left: FbMetric.pagePad, right: FbMetric.pagePad })
          .alignItems(HorizontalAlign.Start)

          // ---- 账目（按类别分组）----
          Row({ space: 8 }) {
            Text('账目')
              .fontSize(FbMetric.fontSmall)
              .fontWeight(FontWeight.Medium)
              .fontColor(FbColors.ink)
            Blank()
            Text(this.entries.length.toString() + ' 条 · 按类别')
              .fontSize(FbMetric.fontTiny)
              .fontColor(FbColors.faint)
          }
          .width('100%')
          .padding({ left: FbMetric.pagePad + 4, right: FbMetric.pagePad + 4, top: 14, bottom: 8 })

          if (this.entries.length === 0) {
            FbEmptyBox({
              title: '这本账还没有账目',
              hint: '存款、基金、保险、房子、车子都可以记进来',
              icon: $r('app.media.fb_ic_ledger')
            })
          } else {
            ForEach(this.groups(), (g: FbGroup<FbLedgerEntry>) => {
              Column({ space: 0 }) {
                // 类别小标题 + 该类别小计
                Row({ space: 8 }) {
                  Text(g.title)
                    .fontSize(FbMetric.fontTiny)
                    .fontWeight(FontWeight.Medium)
                    .fontColor(FbColors.ink)
                  Text(fbMoney(this.sumOf(g.items)))
                    .fontSize(10)
                    .fontColor(FbColors.faint)
                  Blank()
                }
                .width('100%')
                .padding({ top: 10, bottom: 6 })

                Column({ space: 0 }) {
                  ForEach(g.items, (e: FbLedgerEntry, idx: number) => {
                    this.entryRow(e, idx === g.items.length - 1)
                  }, (e: FbLedgerEntry): string => 'le_' + e.id.toString())
                }
                .width('100%')
              }
              .width('100%')
              .padding(FbMetric.cardPad)
              .backgroundColor(FbColors.surface)
              .borderRadius(FbMetric.radius)
              .margin({ left: FbMetric.pagePad, right: FbMetric.pagePad, bottom: 12 })
              .alignItems(HorizontalAlign.Start)
            }, (g: FbGroup<FbLedgerEntry>): string => 'lg_' + g.key)

            Blank().height(16)
          }
        }
        .width('100%')
      }
      .layoutWeight(1)
      .width('100%')
      .scrollBar(BarState.Off)
      .edgeEffect(EdgeEffect.Spring)
      .align(Alignment.TopStart)
    }
    .width('100%')
    .height('100%')
    .backgroundColor(FbColors.paper)
    .alignItems(HorizontalAlign.Start)
  }

  /** 一条账目：名字 + 归属人 + 金额 + 盘点入口 */
  @Builder
  entryRow(e: FbLedgerEntry, isLast: boolean) {
    Column({ space: 0 }) {
      Row({ space: 10 }) {
        Column({ space: 3 }) {
          Row({ space: 6 }) {
            Text(e.name)
              .fontSize(FbMetric.fontBody)
              .fontColor(FbColors.ink)
              .maxLines(1)
              .textOverflow({ overflow: TextOverflow.Ellipsis })
            if (e.ownerName.length > 0) {
              FbTag({ text: e.ownerName, tone: 'muted' })
            }
          }
          .alignItems(VerticalAlign.Center)

          Text('更新于 ' + e.updatedAt)
            .fontSize(10)
            .fontColor(FbColors.faint)
        }
        .alignItems(HorizontalAlign.Start)
        .layoutWeight(1)

        Text(fbMoney(e.amountCent))
          .fontSize(FbMetric.fontBody)
          .fontWeight(FontWeight.Medium)
          .fontColor(e.amountCent < 0 ? FbColors.red : FbColors.ink)

        // 「盘点」：Web 端是每行一个入口，端上保留成一个轻按钮
        Text('盘点')
          .fontSize(10)
          .fontColor(this.accent)
          .padding({ left: 8, right: 8, top: 4, bottom: 4 })
          .backgroundColor(this.accent + '14')
          .borderRadius(FbMetric.radiusPill)
      }
      .width('100%')
      .padding({ top: 11, bottom: 11 })
      .alignItems(VerticalAlign.Center)

      if (!isLast) {
        Divider().color(FbColors.line2)
      }
    }
    .width('100%')
  }

  private isCurrent(id: number): boolean {
    return this.currentId() === id;
  }

  private currentId(): number {
    if (this.bookId > 0) {
      return this.bookId;
    }
    return this.books.length > 0 ? this.books[0].id : 0;
  }

  private currentBook(): FbLedgerBook {
    const hit: FbLedgerBook | undefined = this.books.find((b: FbLedgerBook): boolean => b.id === this.currentId());
    if (hit !== undefined) {
      return hit;
    }
    return { id: 0, name: '账本', netCent: 0, myPerm: 'owner', entryCount: 0 };
  }

  private netCent(): number {
    return this.currentBook().netCent;
  }

  private assetCent(): number {
    let sum: number = 0;
    for (const e of this.entries) {
      if (e.amountCent > 0) {
        sum = sum + e.amountCent;
      }
    }
    return sum;
  }

  private debtCent(): number {
    let sum: number = 0;
    for (const e of this.entries) {
      if (e.amountCent < 0) {
        sum = sum + e.amountCent;
      }
    }
    return sum;
  }

  private sumOf(items: FbLedgerEntry[]): number {
    let sum: number = 0;
    for (const e of items) {
      sum = sum + e.amountCent;
    }
    return sum;
  }

  private groups(): FbGroup<FbLedgerEntry>[] {
    const keys: string[] = [];
    const buckets: FbLedgerEntry[][] = [];
    for (const e of this.entries) {
      const k: string = fbLedgerKindName(e.kind);
      let idx: number = keys.indexOf(k);
      if (idx < 0) {
        keys.push(k);
        buckets.push([]);
        idx = keys.length - 1;
      }
      buckets[idx].push(e);
    }
    const out: FbGroup<FbLedgerEntry>[] = [];
    for (let i = 0; i < keys.length; i++) {
      out.push({
        key: keys[i],
        title: keys[i],
        items: buckets[i],
        count: buckets[i].length.toString() + ' 条'
      });
    }
    return out;
  }
}