import type {
  AppUser,
  BudgetPot,
  Customer,
  DirectoryUser,
  ManagedUser,
  Project,
  PublicSettings,
  Role,
  TimeEntry,
} from '../types';

const TOKEN_KEY = 'pulse_token';

export function getToken(): string | null {
  try {
    return localStorage.getItem(TOKEN_KEY);
  } catch {
    return null;
  }
}
export function setToken(token: string) {
  try {
    localStorage.setItem(TOKEN_KEY, token);
  } catch {
    /* ohne localStorage bleibt die Sitzung nur bis zum Neuladen */
  }
}
export function clearToken() {
  try {
    localStorage.removeItem(TOKEN_KEY);
  } catch {
    /* egal */
  }
}

export class ApiError extends Error {
  status: number;
  constructor(message: string, status: number) {
    super(message);
    this.status = status;
  }
}

let onUnauthorized: (() => void) | null = null;
export function setUnauthorizedHandler(handler: (() => void) | null) {
  onUnauthorized = handler;
}

async function request<T>(path: string, options: RequestInit = {}): Promise<T> {
  const headers = new Headers(options.headers);
  if (options.body && !headers.has('Content-Type')) headers.set('Content-Type', 'application/json');
  const token = getToken();
  if (token) headers.set('Authorization', `Bearer ${token}`);

  let response: Response;
  try {
    response = await fetch(`/api${path}`, { ...options, headers });
  } catch {
    throw new ApiError('Server nicht erreichbar. Bitte Verbindung prüfen.', 0);
  }
  if (response.status === 401 && !path.startsWith('/auth/login')) {
    clearToken();
    onUnauthorized?.();
  }
  const isJson = response.headers.get('content-type')?.includes('application/json');
  const payload = isJson ? await response.json().catch(() => null) : null;
  if (!response.ok) {
    throw new ApiError(payload?.error || `Anfrage fehlgeschlagen (HTTP ${response.status}).`, response.status);
  }
  return payload as T;
}

const get = <T>(path: string) => request<T>(path);
const send = <T>(method: string, path: string, body?: unknown) =>
  request<T>(path, { method, body: body === undefined ? undefined : JSON.stringify(body) });

function qs(params: Record<string, string | number | boolean | null | undefined>) {
  const search = new URLSearchParams();
  for (const [k, v] of Object.entries(params)) {
    if (v === undefined || v === null || v === '') continue;
    search.set(k, String(v));
  }
  const s = search.toString();
  return s ? `?${s}` : '';
}

/** Laedt eine Datei (Export) mit Token und stoesst den Download an. */
export async function download(path: string, fallbackName: string, open = false) {
  const token = getToken();
  let response: Response;
  try {
    response = await fetch(`/api${path}`, { headers: token ? { Authorization: `Bearer ${token}` } : {} });
  } catch {
    throw new ApiError('Server nicht erreichbar.', 0);
  }
  if (!response.ok) {
    const payload = await response.json().catch(() => null);
    throw new ApiError(payload?.error || `Export fehlgeschlagen (HTTP ${response.status}).`, response.status);
  }
  const blob = await response.blob();
  const disposition = response.headers.get('content-disposition') || '';
  const match = disposition.match(/filename\*=UTF-8''([^;]+)/);
  const name = match ? decodeURIComponent(match[1]) : fallbackName;
  const url = URL.createObjectURL(blob);
  if (open && blob.type === 'application/pdf') {
    window.open(url, '_blank', 'noopener');
  } else {
    const a = document.createElement('a');
    a.href = url;
    a.download = name;
    document.body.appendChild(a);
    a.click();
    a.remove();
  }
  setTimeout(() => URL.revokeObjectURL(url), 60000);
}

export { qs };

/* ------------------------------------------------------------ Endpunkte -- */

export const authApi = {
  config: () => get<{ sso_enabled: boolean; sso_label: string; local_login: boolean }>('/auth/config'),
  login: (identifier: string, password: string) =>
    send<{ token: string; user: AppUser }>('POST', '/auth/login', { identifier, password }),
  me: () => get<{ user: AppUser }>('/auth/me'),
  updateMe: (changes: Partial<Pick<AppUser, 'theme' | 'theme_mode' | 'color' | 'avatar'>>) =>
    send<{ user: AppUser }>('PATCH', '/auth/me', changes),
  changePassword: (current_password: string, new_password: string) =>
    send<{ ok: true }>('POST', '/auth/change-password', { current_password, new_password }),
};

export const settingsApi = {
  public: () => get<PublicSettings>('/settings/public'),
  all: () => get<AdminSettings>('/settings'),
  save: (changes: Partial<AdminSettingsInput>) => send<{ ok: true }>('PUT', '/settings', changes),
  ssoTest: () => send<{ ok: true; sample: string[]; checked: number; eligible: number }>('POST', '/settings/sso/test'),
  aiTest: () => send<{ ok: true; model: string; answer: string }>('POST', '/settings/ai/test'),
  aiModels: (apiKey?: string) => send<{ models: AiModel[] }>('POST', '/settings/ai/models', { api_key: apiKey || undefined }),
};

export interface ExportSettings {
  title: string;
  subtitle: string;
  accent: string;
  logo: string | null;
  header_right: string;
  footer_left: string;
  footer_center: string;
  footer_right: string;
  show_signature: boolean;
  signature_left: string;
  signature_right: string;
}
export interface SsoSettings {
  enabled: boolean;
  button_label: string;
  tenant_id: string;
  client_id: string;
  client_secret: string;
  client_secret_set?: boolean;
  configured?: boolean;
  redirect_uri: string;
  local_login: boolean;
}
export interface HrworksSettings {
  enabled: boolean;
  access_key: string;
  secret_access_key: string;
  secret_set?: boolean;
  configured?: boolean;
  project_code: string;
  window_days: number;
  type_map: Record<string, string>;
  holiday_task: string;
  half_day_hours: number;
  last_run: string | null;
  last_result: { created: number; updated: number; removed: number; unchanged: number; hours: number; failed: number } | null;
}

export interface HrworksStatus {
  enabled: boolean;
  configured: boolean;
  project: { id: number; code: string; name: string; type: string; start_date: string } | null;
  project_code: string;
  window_days: number;
  holiday_task: string;
  half_day_hours: number;
  type_map: Record<string, string>;
  last_run: string | null;
  last_result: HrworksSettings['last_result'];
  entries: number;
  hours: number;
  first_date: string | null;
  last_date: string | null;
}

export interface HrworksReport {
  dry_run: boolean;
  from: string;
  to: string;
  created: number;
  updated?: number;
  removed?: number;
  unchanged: number;
  planned_create: number;
  planned_update: number;
  planned_delete: number;
  hours: number;
  failed: { ref: string; error: string }[];
  unmatched_persons: { person_id: string; name: string; email: string | null }[];
  missing_tasks: string[];
  per_person: Record<string, Record<string, { hours: number; days: number }>>;
}

export const hrworksApi = {
  status: () => get<HrworksStatus>('/hrworks/status'),
  test: () =>
    send<{ ok: true; persons: number; persons_with_pulse_account: number; absence_types: { key: string; name: string }[] }>(
      'POST',
      '/hrworks/test',
      {}
    ),
  sync: (apply = false) => send<HrworksReport>('POST', '/hrworks/sync', { apply }),
  entries: () => get<{ count: number; entries: unknown[] }>('/hrworks/entries'),
  removeAll: () => send<{ deleted: number }>('DELETE', '/hrworks/entries'),
};

export interface AiModel {
  id: string;
  created: string | null;
}

export interface AiSettings {
  enabled: boolean;
  api_key: string;
  key_set?: boolean;
  configured?: boolean;
  model: string;
}
export interface AdminSettings extends PublicSettings {
  export: ExportSettings;
  sso: SsoSettings;
  hrworks: HrworksSettings;
  ai: AiSettings;
}
export type AdminSettingsInput = Omit<AdminSettings, 'export' | 'sso' | 'hrworks' | 'ai'> & {
  export: Partial<ExportSettings>;
  sso: Partial<SsoSettings> & { clear_secret?: boolean };
  hrworks: Partial<HrworksSettings> & { clear_secret?: boolean };
  ai: Partial<AiSettings> & { clear_key?: boolean };
};

export interface AssistantAnswer {
  answer: string;
  model: string;
  tools: { name: string; args: Record<string, unknown> }[];
}
export const assistantApi = {
  status: () => get<{ available: boolean; enabled: boolean; model: string }>('/assistant/status'),
  ask: (question: string, verlauf: { frage: string; antwort: string }[]) =>
    send<AssistantAnswer>('POST', '/assistant/ask', { question, verlauf }),
};

export interface AdUser {
  id: string;
  name: string;
  given_name: string | null;
  surname: string | null;
  email: string;
  job_title: string | null;
  department: string | null;
  pulse_user_id: number | null;
  pulse_role: Role | null;
  pulse_active: boolean | null;
  local_match_id: number | null;
}

export const directoryApi = {
  list: (refresh = false) =>
    get<{ configured: boolean; domains: string[]; fetched_at: string | null; users: AdUser[] }>(`/directory/ad-users${refresh ? '?refresh=1' : ''}`),
  import: (ad_ids: string[], role: Role, manager_id: number | null) =>
    send<{ created: number[]; linked: number[]; skipped: string[] }>('POST', '/directory/import', { ad_ids, role, manager_id }),
  sync: () => send<{ total: number; eligible: number; linked: number; updated: number; deactivated: number }>('POST', '/directory/sync'),
};

export const usersApi = {
  directory: () => get<DirectoryUser[]>('/users/directory'),
  list: () => get<{ users: ManagedUser[]; assignable_roles: Role[] }>('/users'),
  create: (data: Record<string, unknown>) => send<AppUser>('POST', '/users', data),
  update: (id: number, data: Record<string, unknown>) => send<AppUser>('PUT', `/users/${id}`, data),
  remove: (id: number) => send<{ ok: true }>('DELETE', `/users/${id}`),
};

export interface CustomerOverview extends Customer {
  projects: Array<
    Pick<Project, 'id' | 'code' | 'name' | 'display_name' | 'type' | 'is_active' | 'used_minutes' | 'budget_hours' | 'earned' | 'open' | 'budget_value' | 'members' | 'end_date'>
  >;
  members: Project['members'];
  used_minutes: number;
  earned: number;
  open: number;
  monthly: number[];
}

export const customersApi = {
  list: () => get<Customer[]>('/customers'),
  overview: () => get<{ months: string[]; customers: CustomerOverview[] }>('/customers/overview'),
  create: (data: Partial<Customer>) => send<Customer>('POST', '/customers', data),
  update: (id: number, data: Partial<Customer>) => send<Customer>('PUT', `/customers/${id}`, data),
  remove: (id: number) => send<{ ok: true }>('DELETE', `/customers/${id}`),
};

export type PotInput = Partial<
  Pick<BudgetPot, 'label' | 'valid_from' | 'valid_to' | 'budget_amount' | 'rate' | 'budget_hours' | 'order_number' | 'notes'>
>;

export const projectsApi = {
  list: (scope?: 'mine', userId?: number) => get<Project[]>(`/projects${qs({ scope, user_id: userId })}`),
  get: (id: number) => get<Project>(`/projects/${id}`),
  create: (data: Record<string, unknown>) => send<Project>('POST', '/projects', data),
  update: (id: number, data: Record<string, unknown>) => send<Project>('PUT', `/projects/${id}`, data),
  remove: (id: number) => send<{ ok: true }>('DELETE', `/projects/${id}`),
  setMembers: (id: number, user_ids: number[]) => send<Project>('PUT', `/projects/${id}/members`, { user_ids }),
  addPot: (id: number, pot: PotInput) => send<Project>('POST', `/projects/${id}/pots`, pot),
  updatePot: (id: number, potId: number, pot: PotInput) => send<Project>('PUT', `/projects/${id}/pots/${potId}`, pot),
  removePot: (id: number, potId: number) => send<Project>('DELETE', `/projects/${id}/pots/${potId}`),
  addTask: (id: number, task: { name: string; billable?: boolean; rate?: number | null }) => send<Project>('POST', `/projects/${id}/tasks`, task),
  updateTask: (id: number, taskId: number, task: Partial<{ name: string; billable: boolean; is_active: boolean; rate: number | null }>) =>
    send<Project>('PUT', `/projects/${id}/tasks/${taskId}`, task),
  removeTask: (id: number, taskId: number) => send<Project>('DELETE', `/projects/${id}/tasks/${taskId}`),
};

export const entriesApi = {
  list: (from: string, to: string, userId?: number, customerId?: number | null) =>
    get<TimeEntry[]>(`/entries${qs({ from, to, user_id: userId, customer_id: customerId || undefined })}`),
  create: (data: { project_id: number; task_id: number | null; entry_date: string; minutes: number; note: string }) =>
    send<{ entry: TimeEntry; warning: string | null }>('POST', '/entries', data),
  update: (id: number, data: Partial<{ project_id: number; task_id: number | null; entry_date: string; minutes: number; note: string }>) =>
    send<{ entry: TimeEntry; warning: string | null }>('PUT', `/entries/${id}`, data),
  remove: (id: number) => send<{ ok: true }>('DELETE', `/entries/${id}`),
};

export type Granularity = 'day' | 'week' | 'month' | 'quarter' | 'year';
export type RankPeriod = 'days' | 'week' | 'month' | 'quarter' | 'year';

export interface SeriesBucket {
  from: string;
  to: string;
  label: string;
  minutes: number;
  billable_minutes: number;
  non_billable_minutes: number;
  amount: number;
}

export interface DashboardData {
  granularity: Granularity;
  rank: RankPeriod;
  rank_range: { from: string; to: string };
  scope: 'all' | 'team';
  team_size: number;
  series: SeriesBucket[];
  kpis: {
    current: SeriesBucket & { capacity_minutes: number; minutes_until_today: number };
    previous: SeriesBucket | null;
    period_label: string;
    previous_label: string | null;
  };
  ranking: Array<{
    user_id: number;
    name: string;
    color: string | null;
    avatar: string | null;
    job_title: string | null;
    is_external: boolean;
    /** Nur bis heute - Grundlage der Auslastung. */
    minutes_until_today: number;
    minutes: number;
    billable_minutes: number;
    non_billable_minutes: number;
    amount: number;
    entries: number;
    capacity_minutes: number;
  }>;
  projects: Array<{ project_id: number; name: string; customer_color: string | null; minutes: number; billable_minutes: number }>;
  recent: Array<{
    id: number;
    user_id: number;
    user_name: string;
    user_color: string | null;
    user_avatar: string | null;
    project_display: string;
    customer_color: string | null;
    task_name: string | null;
    note: string | null;
    entry_date: string;
    minutes: number;
    billable: boolean;
    created_at: string;
  }>;
}

export const dashboardApi = {
  get: (granularity: Granularity, rank: RankPeriod) => get<DashboardData>(`/dashboard${qs({ granularity, rank })}`),
};

export interface GroupRow {
  key: string | number;
  name: string;
  color?: string | null;
  avatar?: string | null;
  minutes: number;
  billable_minutes: number;
  non_billable_minutes: number;
  amount: number;
  user_id?: number;
  customer_id?: number;
  project_id?: number;
  customer_name?: string;
  code?: string;
  type?: string;
  is_external?: boolean;
  capacity_minutes?: number;
  minutes_until_today?: number;
  utilization?: number | null;
}

export interface TimeReport {
  range: { from: string; to: string };
  include_fixed: boolean;
  hide_non_billable: boolean;
  summary: {
    minutes: number;
    billable_minutes: number;
    non_billable_minutes: number;
    amount: number;
    amount_without_fixed: number;
    fixed_amount: number;
    entries: number;
    /** Nur bis heute gebucht - Grundlage der Auslastung. */
    minutes_until_today: number;
  };
  clients: GroupRow[];
  projects: GroupRow[];
  tasks: GroupRow[];
  users: GroupRow[];
}

export interface ProjectDetail {
  project: Project;
  totals: { minutes: number; billable_minutes: number; non_billable_minutes: number; amount: number };
  weekly: Array<{ week_start: string; label: string; minutes: number; billable_minutes: number; cumulative_minutes: number | null }>;
  tasks: GroupRow[];
  team: GroupRow[];
  pots: Array<BudgetPot & { tasks: GroupRow[]; team: GroupRow[] }>;
}

export interface CustomerReport {
  customer: Customer;
  totals: {
    minutes: number;
    billable_minutes: number;
    non_billable_minutes: number;
    amount: number;
    earned: number;
    open: number;
    budget_value: number;
  };
  series: Array<{ month: string; minutes: number; billable_minutes: number; amount: number }>;
  projects: Array<Omit<ProjectDetail, 'weekly'>>;
  team: GroupRow[];
  tasks: GroupRow[];
}

export const reportsApi = {
  time: (params: { from: string; to: string; customer_id?: number | null; team?: number | null; include_fixed?: boolean; hide_non_billable?: boolean }) =>
    get<TimeReport>(
      `/reports/time${qs({
        ...params,
        include_fixed: params.include_fixed ? 1 : undefined,
        hide_non_billable: params.hide_non_billable ? 1 : undefined,
      })}`
    ),
  project: (id: number) => get<ProjectDetail>(`/reports/project/${id}`),
  customer: (id: number) => get<CustomerReport>(`/reports/customer/${id}`),
};