// Server-side persistence for editor-authored chart templates. Each site owns
// its dashboard at sites/<siteId>/chart-templates.json; the export build copies
// that site's file into its staging dir so build:site composes it into the
// bundle as /chart-templates.json for the static viewer to fetch.

import path from "node:path";
import { readFileSync } from "node:fs";
import { writeJsonAtomicSync } from "./jsonFile-server";
import type { Paths } from "./paths";
import { siteChartTemplatesFile, siteIndexDir } from "./site";
import {
  defaultTemplates,
  defaultHomepageTemplates,
  type ChartTemplates,
  type Dashboard,
} from "./chartConfig";

const EXPORT_TEMPLATES_FILE = "chart-templates.json";

// Staging path (NOT served). Composed into a site's bundle as
// /chart-templates.json by build:site.
export function siteTemplatesStagingPath(paths: Paths, siteId: string): string {
  return path.join(siteIndexDir(paths, siteId), EXPORT_TEMPLATES_FILE);
}

function coerce(raw: unknown): ChartTemplates {
  if (!raw || typeof raw !== "object") return defaultTemplates();
  const r = raw as Partial<ChartTemplates>;
  const base = defaultTemplates();
  return {
    version: 1,
    defaultDashboard:
      r.defaultDashboard && Array.isArray(r.defaultDashboard.charts)
        ? (r.defaultDashboard as Dashboard)
        : base.defaultDashboard,
  };
}

export function readTemplates(paths: Paths, siteId: string): ChartTemplates {
  try {
    return coerce(
      JSON.parse(readFileSync(siteChartTemplatesFile(paths, siteId), "utf8")),
    );
  } catch {
    return defaultTemplates();
  }
}

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

export function writeTemplates(
  paths: Paths,
  siteId: string,
  templates: ChartTemplates,
): void {
  writeJsonAtomic(siteChartTemplatesFile(paths, siteId), templates);
}

// Copy a site's canonical templates into its staging dir. Called by the export
// build (build:templates) for each site.
export function syncTemplatesToExport(paths: Paths, siteId: string): void {
  const templates = readTemplates(paths, siteId);
  writeJsonAtomic(siteTemplatesStagingPath(paths, siteId), templates);
}

// ─── Archilyzer hub (homepage) chart templates ───
// The hub owns one cross-site dashboard at homepageChartTemplatesFile
// (sites/_homepage/chart-templates.json). Falls back to the code-level hub
// default (per-site acquisition charts) when unauthored. Read server-side by the
// homepage app and the editor's hub charts authoring; no staging/composition
// step — the homepage app reads it directly at build.

function coerceHomepage(raw: unknown): ChartTemplates {
  if (!raw || typeof raw !== "object") return defaultHomepageTemplates();
  const r = raw as Partial<ChartTemplates>;
  const base = defaultHomepageTemplates();
  return {
    version: 1,
    defaultDashboard:
      r.defaultDashboard && Array.isArray(r.defaultDashboard.charts)
        ? (r.defaultDashboard as Dashboard)
        : base.defaultDashboard,
  };
}

export function readHomepageTemplates(paths: Paths): ChartTemplates {
  try {
    return coerceHomepage(
      JSON.parse(readFileSync(paths.homepageChartTemplatesFile, "utf8")),
    );
  } catch {
    return defaultHomepageTemplates();
  }
}

export function writeHomepageTemplates(
  paths: Paths,
  templates: ChartTemplates,
): void {
  writeJsonAtomic(paths.homepageChartTemplatesFile, templates);
}