// Server-side persistence for search aliases. Two source files:
//   - global:   paths.globalAliasesFile  (<transcriptsDir>/search-aliases.json)
//   - per-site: sites/<siteId>/search-aliases.json
// The editor authors both; the export build merges them (per-site shadows
// global by id) into each site's shipped /search-aliases.json. When the global
// file is absent it falls back to the seeded DEFAULT_ALIASES so a fresh install
// ships useful suggestions out of the box; a missing per-site file = no
// overrides. See common/lib/searchAliases.ts for the pure model + merge.

import { readFileSync } from "node:fs";
import { writeJsonAtomicSync } from "./jsonFile-server";
import type { Paths } from "./paths";
import { siteAliasesFile } from "./site";
import {
  coerceAliasConfig,
  mergeAliases,
  DEFAULT_ALIASES,
  type AliasConfig,
  type SearchAlias,
} from "./searchAliases";

// Indented, no trailing newline — these files' historical bytes.
function writeJsonAtomic(filePath: string, value: unknown): void {
  writeJsonAtomicSync(filePath, value, { newline: false, mkdir: true });
}

// Global dictionary. Absent/unreadable → the seeded defaults (a fresh install
// still offers suggestions). An empty-but-present file → no aliases (the
// operator deleted the defaults deliberately).
export function readGlobalAliases(paths: Paths): AliasConfig {
  try {
    return coerceAliasConfig(
      JSON.parse(readFileSync(paths.globalAliasesFile, "utf8")),
    );
  } catch {
    return { aliases: [...DEFAULT_ALIASES] };
  }
}

export function writeGlobalAliases(paths: Paths, config: AliasConfig): void {
  writeJsonAtomic(paths.globalAliasesFile, config);
}

// Per-site overrides. Absent/unreadable → empty (no overrides).
export function readSiteAliases(paths: Paths, siteId: string): AliasConfig {
  try {
    return coerceAliasConfig(
      JSON.parse(readFileSync(siteAliasesFile(paths, siteId), "utf8")),
    );
  } catch {
    return { aliases: [] };
  }
}

export function writeSiteAliases(
  paths: Paths,
  siteId: string,
  config: AliasConfig,
): void {
  writeJsonAtomic(siteAliasesFile(paths, siteId), config);
}

// The list a site actually ships: global merged with its per-site overrides.
// Read directly by compose-site.ts at build time (source files are available
// there, like duplicates.json), so there's no separate staging step.
export function effectiveSiteAliases(paths: Paths, siteId: string): SearchAlias[] {
  return mergeAliases(
    readGlobalAliases(paths).aliases,
    readSiteAliases(paths, siteId).aliases,
  );
}