"use server";

import { revalidatePath } from "next/cache";
import {
  AUTO_REFRESH_INTERVAL_MAX_SECONDS,
  getSettings,
  AUTO_REFRESH_INTERVAL_MIN_SECONDS,
  DEFAULT_REPORT_DEBOUNCE_PRESET,
  defaultBuildPipeline,
  isReportDebouncePreset,
  MIN_FREE_DISK_GB_MAX,
  RESUME_MARGIN_GB_DEFAULT,
  RESUME_MARGIN_GB_MAX,
  parseSocialLinks,
  PARALLEL_TRANSCRIPTIONS_DEFAULT,
  SLEEP_BETWEEN_DOWNLOADS_MAX_SECONDS,
  TRANSCRIPT_PAGE_HARD_CAP_BYTES,
  TRANSCRIPT_PAGE_MIN_BYTES,
  type SiteSettings,
  type SocialLink,
} from "yt-dlp-transcript-common/lib/settings";
import { saveSettings } from "./saveSettings";
import { socialLinksForSave } from "yt-dlp-transcript-common/lib/socialLinks";
import {
  DEFAULT_COOKIE_MODE,
  isCookieMode,
} from "yt-dlp-transcript-common/lib/cookiePolicy";
import {
  DEFAULT_SOURCE_VIDEO_QUALITY,
  isDownloadFormatPreset,
  isSourceVideoQuality,
} from "yt-dlp-transcript-common/ytdlp/downloadFormat";
import { formValues, type FormState } from "../lib/formState";

// THE SHARED SAVE RESULT of /settings and the four operation-settings forms. A
// failure carries what was submitted, so the form keeps what was typed
// (lib/formState.ts).
export type SaveResult = FormState;

export async function saveSettingsAction(
  _prev: SaveResult | undefined,
  formData: FormData,
): Promise<SaveResult> {
  const values = formValues(formData);
  const adminTitle = String(formData.get("adminTitle") ?? "").trim();
  const homepageUrl = String(formData.get("homepageUrl") ?? "").trim();
  const maxBytesRaw = String(
    formData.get("maxTranscriptPageBytes") ?? "",
  ).trim();
  const cookiesFromBrowser = String(
    formData.get("cookiesFromBrowser") ?? "",
  ).trim();
  const cookieModeRaw = String(formData.get("cookieMode") ?? "").trim();
  const cookieMode = isCookieMode(cookieModeRaw)
    ? cookieModeRaw
    : DEFAULT_COOKIE_MODE;
  const sleepRaw = String(
    formData.get("sleepBetweenDownloadsSeconds") ?? "",
  ).trim();
  const autoRefreshRaw = String(
    formData.get("autoRefreshIntervalSeconds") ?? "",
  ).trim();
  const minFreeDiskRaw = String(formData.get("minFreeDiskGB") ?? "").trim();
  const resumeMarginRaw = String(formData.get("resumeMarginGB") ?? "").trim();
  const inlineTranscribeOnFallback =
    formData.get("inlineTranscribeOnFallback") === "on";
  const skipLiveDownloads = formData.get("skipLiveDownloads") === "on";
  const verifyAvailabilityBeforeClean =
    formData.get("verifyAvailabilityBeforeClean") === "on";
  const buildArchives = formData.get("buildArchives") === "on";
  const archiveStorage = {
    bucket: String(formData.get("archiveStorageBucket") ?? "").trim(),
    publicBaseUrl: String(
      formData.get("archiveStoragePublicBaseUrl") ?? "",
    ).trim(),
  };
  const reportDebouncePresetRaw = String(
    formData.get("reportDebouncePreset") ?? "",
  ).trim();
  const reportDebouncePreset = isReportDebouncePreset(reportDebouncePresetRaw)
    ? reportDebouncePresetRaw
    : DEFAULT_REPORT_DEBOUNCE_PRESET;
  const downloadFormatRaw = String(formData.get("downloadFormat") ?? "").trim();
  const downloadFormat = isDownloadFormatPreset(downloadFormatRaw)
    ? downloadFormatRaw
    : "auto";
  const sourceVideoQualityRaw = String(
    formData.get("sourceVideoQuality") ?? "",
  ).trim();
  const sourceVideoQuality = isSourceVideoQuality(sourceVideoQualityRaw)
    ? sourceVideoQualityRaw
    : DEFAULT_SOURCE_VIDEO_QUALITY;

  if (!adminTitle) {
    return { ok: false, error: "Admin title is required", values };
  }

  const parsed = Number.parseInt(maxBytesRaw, 10);
  if (!Number.isFinite(parsed)) {
    return {
      ok: false,
      error: "maxTranscriptPageBytes must be a number",
      values,
    };
  }
  if (
    parsed < TRANSCRIPT_PAGE_MIN_BYTES ||
    parsed > TRANSCRIPT_PAGE_HARD_CAP_BYTES
  ) {
    return {
      ok: false,
      error: `maxTranscriptPageBytes must be between ${TRANSCRIPT_PAGE_MIN_BYTES} and ${TRANSCRIPT_PAGE_HARD_CAP_BYTES}`,
      values,
    };
  }

  const sleepParsed = Number.parseInt(sleepRaw, 10);
  if (!Number.isFinite(sleepParsed)) {
    return {
      ok: false,
      error: "sleepBetweenDownloadsSeconds must be a number",
      values,
    };
  }
  if (sleepParsed < 0 || sleepParsed > SLEEP_BETWEEN_DOWNLOADS_MAX_SECONDS) {
    return {
      ok: false,
      error: `sleepBetweenDownloadsSeconds must be between 0 and ${SLEEP_BETWEEN_DOWNLOADS_MAX_SECONDS}`,
      values,
    };
  }

  // 0 disables passive refresh; any other value must land in the allowed window.
  const autoRefreshParsed = Number.parseInt(autoRefreshRaw, 10);
  if (!Number.isFinite(autoRefreshParsed)) {
    return {
      ok: false,
      error: "autoRefreshIntervalSeconds must be a number",
      values,
    };
  }
  if (
    autoRefreshParsed !== 0 &&
    (autoRefreshParsed < AUTO_REFRESH_INTERVAL_MIN_SECONDS ||
      autoRefreshParsed > AUTO_REFRESH_INTERVAL_MAX_SECONDS)
  ) {
    return {
      ok: false,
      error: `autoRefreshIntervalSeconds must be 0 (off) or between ${AUTO_REFRESH_INTERVAL_MIN_SECONDS} and ${AUTO_REFRESH_INTERVAL_MAX_SECONDS}`,
      values,
    };
  }

  const minFreeDiskParsed = Number.parseInt(minFreeDiskRaw, 10);
  if (!Number.isFinite(minFreeDiskParsed)) {
    return { ok: false, error: "minFreeDiskGB must be a number", values };
  }
  if (minFreeDiskParsed < 0 || minFreeDiskParsed > MIN_FREE_DISK_GB_MAX) {
    return {
      ok: false,
      error: `minFreeDiskGB must be between 0 and ${MIN_FREE_DISK_GB_MAX}`,
      values,
    };
  }

  // A settings.json (or a form) predating the field sends nothing; fall back to
  // the default rather than rejecting the whole save over a field the operator
  // never saw.
  const resumeMarginParsed =
    resumeMarginRaw === ""
      ? RESUME_MARGIN_GB_DEFAULT
      : Number.parseInt(resumeMarginRaw, 10);
  if (!Number.isFinite(resumeMarginParsed)) {
    return { ok: false, error: "resumeMarginGB must be a number", values };
  }
  if (resumeMarginParsed < 0 || resumeMarginParsed > RESUME_MARGIN_GB_MAX) {
    return {
      ok: false,
      error: `resumeMarginGB must be between 0 and ${RESUME_MARGIN_GB_MAX}`,
      values,
    };
  }

  let socialInput: unknown;
  try {
    socialInput = JSON.parse(String(formData.get("socialLinksJson") ?? "[]"));
  } catch {
    return { ok: false, error: "Social links payload is malformed", values };
  }
  const socialParsed = parseSocialLinks(socialInput);
  if (
    Array.isArray(socialInput) &&
    socialParsed.length !== socialInput.length
  ) {
    return {
      ok: false,
      error:
        "Each social link needs a label, URL (http(s)://, mailto:, or /), and SVG.",
      values,
    };
  }
  // A link whose SVG is unchanged from settings.json is kept as it is; a new
  // or edited one is checked (lib/socialLinks.ts socialLinksForSave).
  const checked = socialLinksForSave(socialParsed, getSettings().socialLinks);
  if ("refused" in checked) {
    return {
      ok: false,
      error: `Social link "${checked.refused.label}" has an invalid SVG: ${checked.refused.problem}.`,
      values,
    };
  }
  const socialLinks: SocialLink[] = checked.links;

  // Build pipeline. Values are clamped/coerced by sanitizeBuildPipeline inside
  // the settings schema on save, so we only read the form here (NaN/blank → default).
  const dB = defaultBuildPipeline();
  const buildPipeline = {
    maxParallelBuilds: Number.parseInt(
      String(formData.get("maxParallelBuilds") ?? "").trim(),
      10,
    ),
    dockerImage:
      String(formData.get("dockerImage") ?? "").trim() || dB.dockerImage,
    dockerfile:
      String(formData.get("dockerfile") ?? "").trim() || dB.dockerfile,
  };

  // ONLY WHAT THIS FORM EDITS. saveSettings merges the patch over the stored
  // file, so every block edited elsewhere — workers (/workers), syncScheduler
  // (/operations/sync), autoQueue and channelPriority (the operation pages and
  // /channels), savedVideoBackup (/saved-videos), storage (/storage) and the
  // four operation blocks (/operations/<id>) — survives a save here without
  // being read and re-listed. Before slice 4a this literal named all 31 fields
  // and carried each foreign block through `getSettings()`, which is how an
  // unrelated save once disarmed a sweep.
  const next: Partial<SiteSettings> = {
    adminTitle,
    maxTranscriptPageBytes: parsed,
    cookiesFromBrowser,
    cookieMode,
    sleepBetweenDownloadsSeconds: sleepParsed,
    downloadFormat,
    sourceVideoQuality,
    minFreeDiskGB: minFreeDiskParsed,
    resumeMarginGB: resumeMarginParsed,
    // Vestigial (the worker list is the parallelism; kept only for rollback),
    // and this form has always reset it to the default.
    parallelTranscriptions: PARALLEL_TRANSCRIPTIONS_DEFAULT,
    inlineTranscribeOnFallback,
    skipLiveDownloads,
    verifyAvailabilityBeforeClean,
    buildArchives,
    archiveStorage,
    reportDebouncePreset,
    autoRefreshIntervalSeconds: autoRefreshParsed,
    socialLinks,
    homepageUrl,
    buildPipeline,
  };
  try {
    await saveSettings(next);
  } catch (e) {
    return { ok: false, error: (e as Error).message, values };
  }
  revalidatePath("/settings");
  return { ok: true };
}