/**
 * Documents Generator API client (Phase L1-L3).
 *
 * Letterheads (Briefpapier), print templates (block compositions),
 * block registry and placeholders — all under /reports/... (documents
 * router of the report_generator plugin).
 */

import { apiClient, apiDelete, apiGet, apiPost, apiPut } from './client';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';

// ─── Types ─────────────────────────────────────────────────────────────────

export interface DocBlock {
  id: string;
  type: string;
  config: Record<string, unknown>;
}

export interface LetterheadPageConfig {
  size?: string;
  orientation?: string;
  margins?: { top?: number; right?: number; bottom?: number; left?: number };
}

export interface LetterheadConfig {
  page?: LetterheadPageConfig;
  header?: { enabled: boolean; blocks: DocBlock[] };
  footer?: { enabled: boolean; blocks: DocBlock[] };
  watermark?: { enabled: boolean; text?: string };
}

export interface Letterhead {
  id: string;
  name: string;
  description: string;
  config: LetterheadConfig;
  is_default: boolean;
  created_by: string;
  created_at?: string | null;
  updated_at?: string | null;
}

export interface PrintTemplate {
  id: string;
  name: string;
  description: string;
  letterhead_id: string | null;
  entity_type: string;
  blocks: DocBlock[];
  output_format: string;
  created_by: string;
  created_at?: string | null;
  updated_at?: string | null;
}

export interface DocumentBlockType {
  type: string;
  label: string;
  category: string;
  description: string;
  fields: Record<string, string>;
  builtin: boolean;
  contributed_by?: string | null;
}

export interface DocumentPlaceholder {
  key: string;
  label: string;
  example: string;
}

export interface DocumentAsset {
  id: string;
  letterhead_id: string | null;
  filename: string;
  mime_type: string;
  size_bytes: number;
  data_url: string | null;
  created_at?: string | null;
}

export interface LetterheadInput {
  name: string;
  description?: string;
  config?: LetterheadConfig;
  is_default?: boolean;
}

export interface PrintTemplateInput {
  name: string;
  description?: string;
  letterhead_id?: string | null;
  entity_type?: string;
  blocks?: DocBlock[];
  output_format?: string;
}

// ─── Query Keys ─────────────────────────────────────────────────────────────

export const DOC_QUERY_KEYS = {
  letterheads: ['documents', 'letterheads'] as const,
  letterhead: (id: string) => ['documents', 'letterheads', id] as const,
  templates: ['documents', 'print-templates'] as const,
  template: (id: string) => ['documents', 'print-templates', id] as const,
  blocks: ['documents', 'block-types'] as const,
  placeholders: (entityType?: string) => ['documents', 'placeholders', entityType ?? 'all'] as const,
  assets: (letterheadId: string) => ['documents', 'assets', letterheadId] as const,
};

// ─── Fetch helpers ─────────────────────────────────────────────────────────

async function fetchLetterheads(): Promise<Letterhead[]> {
  const res = await apiGet<{ items: Letterhead[]; total: number }>('/reports/letterheads');
  return res.items ?? [];
}

async function fetchTemplates(): Promise<PrintTemplate[]> {
  const res = await apiGet<{ items: PrintTemplate[]; total: number }>('/reports/print-templates');
  return res.items ?? [];
}

async function fetchBlockTypes(): Promise<DocumentBlockType[]> {
  return apiGet<DocumentBlockType[]>('/reports/document-blocks');
}

async function fetchPlaceholders(entityType?: string): Promise<Record<string, DocumentPlaceholder[]>> {
  const url = entityType
    ? `/reports/document-placeholders?entity_type=${encodeURIComponent(entityType)}`
    : '/reports/document-placeholders';
  return apiGet<Record<string, DocumentPlaceholder[]>>(url);
}

async function fetchAssets(letterheadId: string): Promise<DocumentAsset[]> {
  return apiGet<DocumentAsset[]>(`/reports/letterheads/${letterheadId}/assets`);
}

// ─── Hooks: Letterheads ─────────────────────────────────────────────────────

export function useLetterheads() {
  return useQuery<Letterhead[]>({
    queryKey: DOC_QUERY_KEYS.letterheads,
    queryFn: fetchLetterheads,
  });
}

export function useCreateLetterhead() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: (input: LetterheadInput) =>
      apiPost<Letterhead>('/reports/letterheads', input),
    onSuccess: () => qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.letterheads }),
  });
}

export function useUpdateLetterhead() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: ({ id, input }: { id: string; input: Partial<LetterheadInput> }) =>
      apiPut<Letterhead>(`/reports/letterheads/${id}`, input),
    onSuccess: (_data, vars) => {
      qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.letterheads });
      qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.letterhead(vars.id) });
    },
  });
}

export function useDeleteLetterhead() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: (id: string) => apiDelete(`/reports/letterheads/${id}`),
    onSuccess: () => qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.letterheads }),
  });
}

// ─── Hooks: Print Templates ─────────────────────────────────────────────────

export function usePrintTemplates() {
  return useQuery<PrintTemplate[]>({
    queryKey: DOC_QUERY_KEYS.templates,
    queryFn: fetchTemplates,
  });
}

export function useCreatePrintTemplate() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: (input: PrintTemplateInput) =>
      apiPost<PrintTemplate>('/reports/print-templates', input),
    onSuccess: () => qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.templates }),
  });
}

export function useUpdatePrintTemplate() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: ({ id, input }: { id: string; input: Partial<PrintTemplateInput> }) =>
      apiPut<PrintTemplate>(`/reports/print-templates/${id}`, input),
    onSuccess: (_data, vars) => {
      qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.templates });
      qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.template(vars.id) });
    },
  });
}

export function useDeletePrintTemplate() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: (id: string) => apiDelete(`/reports/print-templates/${id}`),
    onSuccess: () => qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.templates }),
  });
}

// ─── Hooks: Registry ────────────────────────────────────────────────────────

export function useDocumentBlockTypes() {
  return useQuery<DocumentBlockType[]>({
    queryKey: DOC_QUERY_KEYS.blocks,
    queryFn: fetchBlockTypes,
    staleTime: 5 * 60 * 1000,
  });
}

export function useDocumentPlaceholders(entityType?: string, enabled = true) {
  return useQuery<Record<string, DocumentPlaceholder[]>>({
    queryKey: DOC_QUERY_KEYS.placeholders(entityType),
    queryFn: () => fetchPlaceholders(entityType),
    enabled,
    staleTime: 5 * 60 * 1000,
  });
}

export function useLetterheadAssets(letterheadId: string | null | undefined) {
  return useQuery<DocumentAsset[]>({
    queryKey: DOC_QUERY_KEYS.assets(letterheadId ?? 'none'),
    queryFn: () => fetchAssets(letterheadId as string),
    enabled: !!letterheadId,
  });
}

export function useUploadLetterheadAsset() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: ({ letterheadId, file }: { letterheadId: string; file: File }) => {
      const form = new FormData();
      form.append('file', file);
      return apiClient
        .post(`/reports/letterheads/${letterheadId}/assets`, form, {
          headers: { 'Content-Type': 'multipart/form-data' },
        })
        .then((r) => r.data as DocumentAsset);
    },
    onSuccess: (_data, vars) =>
      qc.invalidateQueries({ queryKey: DOC_QUERY_KEYS.assets(vars.letterheadId) }),
  });
}

// ─── Preview & Render ──────────────────────────────────────────────────────

export interface PreviewInput {
  blocks: DocBlock[];
  letterhead_config: LetterheadConfig | null;
  entity_type?: string | null;
  data?: Record<string, unknown> | null;
}

export function usePreviewDocument() {
  return useMutation({
    mutationFn: (input: PreviewInput) =>
      apiPost<{ html: string }>('/reports/documents/preview', input),
  });
}

export interface RenderInput {
  templateId: string;
  entityType: string;
  entityId: string;
  outputFormat?: string;
}

export async function renderPrintTemplate(input: RenderInput): Promise<Blob> {
  const response = await apiClient.post(
    `/reports/print-templates/${input.templateId}/render`,
    {
      entity_type: input.entityType,
      entity_id: input.entityId,
      output_format: input.outputFormat ?? 'pdf',
    },
    { responseType: 'blob' },
  );
  return response.data as Blob;
}

export function useRenderPrintTemplate() {
  return useMutation({ mutationFn: renderPrintTemplate });
}