/**
 * 将设计文档中的 branding_json 拆为表单字段，供运营可视化编辑。
 */
export interface BrandingForm {
  documentTitle: string
  login: {
    markLine: string
    headline: string
    slogan: string
    cardWelcome: string
    footerCopyright: string
    logoUrl: string
    faviconUrl: string
    themePrimary: string
  }
  apply: {
    pageTitle: string
    headerSubtitle: string
  }
  review: {
    pageTitle: string
    footerCopyright: string
  }
  admin: {
    loginTitle: string
    footerCopyright: string
    sidebarProductName: string
  }
}

export function emptyBrandingForm(): BrandingForm {
  return {
    documentTitle: '',
    login: {
      markLine: '',
      headline: '',
      slogan: '',
      cardWelcome: '',
      footerCopyright: '',
      logoUrl: '',
      faviconUrl: '',
      themePrimary: '',
    },
    apply: { pageTitle: '', headerSubtitle: '' },
    review: { pageTitle: '', footerCopyright: '' },
    admin: { loginTitle: '', footerCopyright: '', sidebarProductName: '' },
  }
}

function asRecord(v: unknown): Record<string, unknown> {
  return v !== null && typeof v === 'object' && !Array.isArray(v) ? (v as Record<string, unknown>) : {}
}

/** 去掉零宽字符与首尾空白 */
export function normalizeDisplayWhitespace(s: string): string {
  return s.replace(/[\u200B-\u200D\uFEFF]/gu, '').trim()
}

/** 是否有可见字符（用于未配置、仅空格或零宽符时不覆盖端上默认文案） */
export function hasVisibleText(s: string): boolean {
  return /\S/u.test(normalizeDisplayWhitespace(s))
}

function str(r: Record<string, unknown>, key: string): string {
  const x = r[key]
  if (x == null) return ''
  if (typeof x === 'string') return x
  if (typeof x === 'number' && Number.isFinite(x)) return String(x)
  return ''
}

export function brandingFormFromApi(json: unknown | null | undefined): BrandingForm {
  const b = emptyBrandingForm()
  if (json == null) return b
  let parsed: unknown = json
  if (typeof parsed === 'string') {
    const t = parsed.trim()
    if (!t) return b
    try {
      parsed = JSON.parse(t) as unknown
    } catch {
      return b
    }
  }
  const root = asRecord(parsed)
  b.documentTitle = normalizeDisplayWhitespace(str(root, 'documentTitle'))
  const login = asRecord(root.login)
  b.login.markLine = normalizeDisplayWhitespace(str(login, 'markLine'))
  b.login.headline = normalizeDisplayWhitespace(str(login, 'headline'))
  b.login.slogan = normalizeDisplayWhitespace(str(login, 'slogan'))
  b.login.cardWelcome = normalizeDisplayWhitespace(str(login, 'cardWelcome'))
  b.login.footerCopyright = normalizeDisplayWhitespace(str(login, 'footerCopyright'))
  b.login.logoUrl = normalizeDisplayWhitespace(str(login, 'logoUrl'))
  b.login.faviconUrl = normalizeDisplayWhitespace(str(login, 'faviconUrl'))
  b.login.themePrimary = normalizeDisplayWhitespace(str(login, 'themePrimary'))
  const apply = asRecord(root.apply)
  b.apply.pageTitle = normalizeDisplayWhitespace(str(apply, 'pageTitle'))
  b.apply.headerSubtitle = normalizeDisplayWhitespace(str(apply, 'headerSubtitle'))
  const review = asRecord(root.review)
  b.review.pageTitle = normalizeDisplayWhitespace(str(review, 'pageTitle'))
  b.review.footerCopyright = normalizeDisplayWhitespace(str(review, 'footerCopyright'))
  const admin = asRecord(root.admin)
  b.admin.loginTitle = normalizeDisplayWhitespace(str(admin, 'loginTitle'))
  b.admin.footerCopyright = normalizeDisplayWhitespace(str(admin, 'footerCopyright'))
  b.admin.sidebarProductName = normalizeDisplayWhitespace(str(admin, 'sidebarProductName'))
  return b
}

/** 选手端报名页主标题（导航栏 / 表单大标题共用） */
export function participantApplyPageTitle(brand: BrandingForm, competitionName: string): string {
  const a = brand.apply?.pageTitle
  if (hasVisibleText(a)) return normalizeDisplayWhitespace(a)
  const n = normalizeDisplayWhitespace(competitionName)
  return n ? `${n} · 赛事报名` : '赛事报名'
}

/** 评审工作台顶栏标题（对齐 branding.review.pageTitle） */
export function reviewWorkspacePageTitle(brand: BrandingForm, competitionName: string): string {
  const r = brand.review?.pageTitle
  if (hasVisibleText(r)) return normalizeDisplayWhitespace(r)
  const n = normalizeDisplayWhitespace(competitionName)
  return n ? `${n} · 项目评审` : '项目评审'
}

/** 去掉空字符串键，减少存储体积 */
export function brandingJsonFromForm(form: BrandingForm): Record<string, unknown> | null {
  const out: Record<string, unknown> = {}
  if (form.documentTitle.trim()) out.documentTitle = form.documentTitle.trim()

  const login: Record<string, string> = {}
  if (form.login.markLine.trim()) login.markLine = form.login.markLine.trim()
  if (form.login.headline.trim()) login.headline = form.login.headline.trim()
  if (form.login.slogan.trim()) login.slogan = form.login.slogan.trim()
  if (form.login.cardWelcome.trim()) login.cardWelcome = form.login.cardWelcome.trim()
  if (form.login.footerCopyright.trim()) login.footerCopyright = form.login.footerCopyright.trim()
  if (form.login.logoUrl.trim()) login.logoUrl = form.login.logoUrl.trim()
  if (form.login.faviconUrl.trim()) login.faviconUrl = form.login.faviconUrl.trim()
  if (form.login.themePrimary.trim()) login.themePrimary = form.login.themePrimary.trim()
  if (Object.keys(login).length) out.login = login

  const apply: Record<string, string> = {}
  if (form.apply.pageTitle.trim()) apply.pageTitle = form.apply.pageTitle.trim()
  if (form.apply.headerSubtitle.trim()) apply.headerSubtitle = form.apply.headerSubtitle.trim()
  if (Object.keys(apply).length) out.apply = apply

  const review: Record<string, string> = {}
  if (form.review.pageTitle.trim()) review.pageTitle = form.review.pageTitle.trim()
  if (form.review.footerCopyright.trim()) review.footerCopyright = form.review.footerCopyright.trim()
  if (Object.keys(review).length) out.review = review

  const admin: Record<string, string> = {}
  if (form.admin.loginTitle.trim()) admin.loginTitle = form.admin.loginTitle.trim()
  if (form.admin.footerCopyright.trim()) admin.footerCopyright = form.admin.footerCopyright.trim()
  if (form.admin.sidebarProductName.trim()) admin.sidebarProductName = form.admin.sidebarProductName.trim()
  if (Object.keys(admin).length) out.admin = admin

  return Object.keys(out).length ? out : null
}