/**
 * 站点设置：页头滚动信息 + 侧栏顺序/显隐。
 *
 * 接口是公开读、登录后写；写的时候带 `version` 做乐观锁，
 * 冲突（多标签页同时改）时返回 409，页面提示刷新。
 */
import type { Category } from './data/types'

export type SettingsTone = 'plain' | 'primary' | 'success' | 'neutral'

export type HeaderItem = {
  text: string
  tag?: string | null
  tone: SettingsTone
}

export type SectionSettings = {
  hidden: string[]
  order: string[]
  titles: Record<string, string>
  limits: Record<string, number>
}

export type ProfileSettings = {
  name: string
  role: string
  description: string
  /** 完整文案，如「IP属地：局域网」 */
  location: string
  /** 头像地址；空表示用图标占位 */
  avatar: string
}

export type SiteSettings = {
  header: {
    enabled: boolean
    /** 滚动一轮的秒数（8–120） */
    speed: number
    items: HeaderItem[]
  }
  sidebar: {
    hidden: string[]
    order: string[]
    /** 隐藏的分组：`分区id/分组id` */
    hidden_groups: string[]
    /** 强制显示的分组（覆盖数据库 show_in_sidebar=0） */
    shown_groups: string[]
    /** 每个分区下的分组顺序：分区 id → 分组 id 列表 */
    group_order: Record<string, string[]>
  }
  sections: SectionSettings
  profile: ProfileSettings
}

export type SettingsDocument = {
  version: number
  settings: SiteSettings
}

export type SettingsResult =
  | { ok: true; document: SettingsDocument }
  | { ok: false; status: number; error: string }

export const TONE_OPTIONS: { value: SettingsTone; label: string }[] = [
  { value: 'plain', label: '无底色' },
  { value: 'neutral', label: '灰色' },
  { value: 'primary', label: '品牌色' },
  { value: 'success', label: '成功绿' },
]

export function defaultSettings(): SiteSettings {
  return {
    header: {
      enabled: true,
      speed: 24,
      items: [
        { text: '共 {count} 个本地应用', tone: 'plain' },
        { text: '{project}', tag: '本地', tone: 'primary' },
        { text: '{status}', tag: '状态', tone: 'success' },
      ],
    },
    sidebar: {
      hidden: [],
      order: [],
      hidden_groups: [],
      shown_groups: [],
      group_order: {},
    },
    sections: { hidden: [], order: [], titles: {}, limits: {} },
    profile: {
      name: '本地管理员',
      role: '管理员',
      description: '本地静态站点托管与预览，所有项目都运行在这台机器上。',
      location: 'IP属地：局域网',
      avatar: '',
    },
  }
}

/** 占位符替换：`{count}` / `{project}` / `{status}` */
export function fillHeaderText(
  text: string,
  context: { count: number; project?: string; live: boolean },
): string {
  return text
    .replaceAll('{count}', String(context.count))
    .replaceAll('{project}', context.project ?? '—')
    .replaceAll('{status}', context.live ? '实时同步已连接' : '等待服务连接')
}

export async function fetchSettings(): Promise<SettingsDocument> {
  try {
    const response = await fetch('/api/settings', { credentials: 'same-origin' })
    if (!response.ok) throw new Error(String(response.status))
    return (await response.json()) as SettingsDocument
  } catch {
    return { version: 0, settings: defaultSettings() }
  }
}

export async function saveSettings(
  version: number,
  settings: SiteSettings,
): Promise<SettingsResult> {  try {
    const response = await fetch('/api/settings', {
      method: 'PATCH',
      credentials: 'same-origin',
      headers: { 'content-type': 'application/json' },
      body: JSON.stringify({ version, settings }),
    })

    if (response.ok) {
      return { ok: true, document: (await response.json()) as SettingsDocument }
    }

    const payload = (await response.json().catch(() => null)) as { error?: string } | null
    return {
      ok: false,
      status: response.status,
      error: payload?.error ?? `保存失败（${response.status}）`,
    }
  } catch (error) {
    return {
      ok: false,
      status: 0,
      error: error instanceof Error ? error.message : '网络错误',
    }
  }
}

/**
 * 按设置重排侧栏：先按 `order`，未列出的保持原顺序，`hidden` 过滤掉。
 */export function applySidebarSettings<T extends { id: string }>(
  categories: T[],
  sidebar: SiteSettings['sidebar'],
): T[] {
  return orderAndFilter(categories, sidebar)
}

/** 首页卡片：过滤隐藏、按 order 排序（未列出的保持原顺序） */
export function applySectionSettings<T extends { id: string }>(
  categories: T[],
  sections: SectionSettings,
): T[] {
  return orderAndFilter(categories, sections)
}

/**
 * 侧栏子分类（分组）：按设置过滤、排序。
 *
 * 数据库里的 `show_in_sidebar` 是默认值；`shown_groups` 可以把它强行打开，
 * `hidden_groups` 则再隐藏一层。
 */
export function applySidebarGroups(
  categories: Category[],
  sidebar: SiteSettings['sidebar'],
): Category[] {
  return categories.map((category) => {
    if (category.kind === 'apps') {
      return { ...category, groups: filterGroups(category.groups, category.id, sidebar) }
    }
    if (category.kind === 'posters') {
      return { ...category, groups: filterGroups(category.groups, category.id, sidebar) }
    }
    return { ...category, groups: filterGroups(category.groups, category.id, sidebar) }
  })
}

/** 按设置过滤、排序某个分区下的分组 */
function filterGroups<T extends { id: string }>(
  groups: T[],
  categoryId: string,
  sidebar: SiteSettings['sidebar'],
): T[] {
  const hidden = new Set(sidebar.hidden_groups)
  const shown = new Set(sidebar.shown_groups)
  const ranks = new Map(
    (sidebar.group_order[categoryId] ?? []).map((id, index) => [id, index] as const),
  )

  return groups
    .filter((group) => {
      const key = `${categoryId}/${group.id}`
      const showInSidebar = (group as { showInSidebar?: boolean }).showInSidebar
      return !hidden.has(key) && (showInSidebar !== false || shown.has(key))
    })
    .map((group, index) => ({
      group,
      index,
      rank: ranks.get(group.id) ?? Number.MAX_SAFE_INTEGER,
    }))
    .sort((a, b) => (a.rank === b.rank ? a.index - b.index : a.rank - b.rank))
    .map((entry) => entry.group)
}

/** 卡片标题：设置里的覆盖值优先 */
export function sectionTitle(
  id: string,
  fallback: string,
  sections: SectionSettings,
): string {
  const override = sections.titles[id]
  return override !== undefined && override.trim() !== '' ? override : fallback
}

/** 卡片预览条数：设置里的覆盖值优先 */
export function sectionLimit(
  id: string,
  fallback: number,
  sections: SectionSettings,
): number {
  const override = sections.limits[id]
  return typeof override === 'number' && override > 0 ? override : fallback
}

function orderAndFilter<T extends { id: string }>(  categories: T[],
  config: { hidden: string[]; order: string[] },
): T[] {
  const hidden = new Set(config.hidden)
  const ranks = new Map(config.order.map((id, index) => [id, index]))

  return categories
    .filter((category) => !hidden.has(category.id))
    .map((category, index) => ({
      category,
      index,
      rank: ranks.get(category.id) ?? Number.MAX_SAFE_INTEGER,
    }))
    .sort((a, b) => (a.rank === b.rank ? a.index - b.index : a.rank - b.rank))
    .map((entry) => entry.category)
}

// ---------- 分区（首页卡片 / 侧栏项）的新增与删除 ----------

export type NewCategory = { id: string; title: string; kind: 'apps' | 'posters' | 'articles' }

export type SimpleResult = { ok: true } | { ok: false; error: string }

export async function createCategory(input: NewCategory): Promise<SimpleResult> {
  try {
    const response = await fetch('/api/categories', {
      method: 'POST',
      credentials: 'same-origin',
      headers: { 'content-type': 'application/json' },
      body: JSON.stringify(input),
    })
    if (response.ok) return { ok: true }
    const payload = (await response.json().catch(() => null)) as { error?: string } | null
    return { ok: false, error: payload?.error ?? `创建失败（${response.status}）` }
  } catch (error) {
    return { ok: false, error: error instanceof Error ? error.message : '网络错误' }
  }
}

export async function deleteCategory(id: string): Promise<SimpleResult> {
  try {
    const response = await fetch(`/api/categories/${encodeURIComponent(id)}`, {
      method: 'DELETE',
      credentials: 'same-origin',
    })
    if (response.ok) return { ok: true }
    const payload = (await response.json().catch(() => null)) as { error?: string } | null
    return { ok: false, error: payload?.error ?? `删除失败（${response.status}）` }
  } catch (error) {
    return { ok: false, error: error instanceof Error ? error.message : '网络错误' }
  }
}

/** 修改分区（归类、标题、图标、色条、预览条数） */
export type UpdateCategoryInput = {
  title?: string
  icon?: string
  barColor?: string
  kind?: 'apps' | 'posters' | 'articles'
  previewLimit?: number
  emptyText?: string
  /** 首页卡片预览哪个节点（分区自己或其分组） */
  blockNodeKey?: string
}

export async function updateCategory(
  id: string,
  patch: UpdateCategoryInput,
): Promise<SimpleResult> {
  try {
    const response = await fetch(`/api/categories/${encodeURIComponent(id)}`, {
      method: 'PATCH',
      credentials: 'same-origin',
      headers: { 'content-type': 'application/json' },
      body: JSON.stringify(patch),
    })
    if (response.ok) return { ok: true }
    const payload = (await response.json().catch(() => null)) as { error?: string } | null
    return { ok: false, error: payload?.error ?? `保存失败（${response.status}）` }
  } catch (error) {
    return { ok: false, error: error instanceof Error ? error.message : '网络错误' }
  }
}

// ---------- 分组（子分类） ----------

export async function createGroup(
  sectionId: string,
  input: { id: string; title: string },
): Promise<SimpleResult> {
  try {
    const response = await fetch(
      `/api/categories/${encodeURIComponent(sectionId)}/groups`,
      {
        method: 'POST',
        credentials: 'same-origin',
        headers: { 'content-type': 'application/json' },
        body: JSON.stringify(input),
      },
    )
    if (response.ok) return { ok: true }
    const payload = (await response.json().catch(() => null)) as { error?: string } | null
    return { ok: false, error: payload?.error ?? `创建失败（${response.status}）` }
  } catch (error) {
    return { ok: false, error: error instanceof Error ? error.message : '网络错误' }
  }
}

export async function updateGroup(
  id: string,
  patch: { title?: string; showInSidebar?: boolean },
): Promise<SimpleResult> {
  try {
    const response = await fetch(`/api/groups/${encodeURIComponent(id)}`, {
      method: 'PATCH',
      credentials: 'same-origin',
      headers: { 'content-type': 'application/json' },
      body: JSON.stringify(patch),
    })
    if (response.ok) return { ok: true }
    const payload = (await response.json().catch(() => null)) as { error?: string } | null
    return { ok: false, error: payload?.error ?? `保存失败（${response.status}）` }
  } catch (error) {
    return { ok: false, error: error instanceof Error ? error.message : '网络错误' }
  }
}

export async function deleteGroup(id: string): Promise<SimpleResult> {
  try {
    const response = await fetch(`/api/groups/${encodeURIComponent(id)}`, {
      method: 'DELETE',
      credentials: 'same-origin',
    })
    if (response.ok) return { ok: true }
    const payload = (await response.json().catch(() => null)) as { error?: string } | null
    return { ok: false, error: payload?.error ?? `删除失败（${response.status}）` }
  } catch (error) {
    return { ok: false, error: error instanceof Error ? error.message : '网络错误' }
  }
}