import path from 'node:path';
import * as vscode from 'vscode';
import { isArchifyFile } from '../sources/detect';
import { log } from '../util/log';
import { Brand, brandValueAt, loadBrandCatalog } from './brands';

const JSON_SOURCES = '**/*.{architecture,workflow,sequence,dataflow,lifecycle}.json';

export const BRAND_COMPLETION_SELECTOR: vscode.DocumentSelector = [
  { pattern: '**/*.archify' },
  { language: 'json', pattern: JSON_SOURCES },
  { language: 'jsonc', pattern: JSON_SOURCES },
];

/** Suggests Archify's built-in brand IDs for `brand` values. */
export class BrandCompletionProvider implements vscode.CompletionItemProvider {
  private brands: Brand[] | undefined;

  constructor(private readonly extensionPath: string) {}

  private catalog(): Brand[] {
    if (!this.brands) {
      try {
        this.brands = loadBrandCatalog(path.join(this.extensionPath, 'vendor', 'archify', 'brand-marks', 'catalog.json'));
      } catch (error) {
        log().error(`Could not read the Archify brand catalog: ${error instanceof Error ? error.message : String(error)}`);
        this.brands = [];
      }
    }
    return this.brands;
  }

  provideCompletionItems(document: vscode.TextDocument, position: vscode.Position): vscode.CompletionItem[] | undefined {
    const linePrefix = document.lineAt(position.line).text.slice(0, position.character);
    const value = brandValueAt(linePrefix, isArchifyFile(document.fileName) ? 'yaml' : 'json');
    if (!value) return undefined;
    const range = new vscode.Range(position.translate(0, -value.typed.length), position);
    return this.catalog().map((brand) => {
      const item = new vscode.CompletionItem({ label: brand.id, description: brand.title }, vscode.CompletionItemKind.Value);
      item.detail = `${brand.title} · ${brand.category}`;
      if (brand.aliases.length) item.documentation = `Also matches: ${brand.aliases.join(', ')}`;
      // Typing an alias or the product name finds the brand too.
      item.filterText = [brand.id, ...brand.aliases, brand.title].join(' ');
      item.range = range;
      return item;
    });
  }
}