import fs from "node:fs";
import { buildHomepageSummary } from "../../common/lib/homepageSummary";
import type { Site } from "../../common/lib/site";
import type { VideoStat } from "../../common/lib/stats";

// THE HOMEPAGE E2E READS A SYNTHETIC SUMMARY, never the operator's.
//
// The pages' numbers come from homepage-summary.json, which compose writes into
// public/ from a real corpus — gitignored, so a fresh clone or worktree has
// none, and the data specs used to skip there (release 10: 8 of 29). So the
// e2e dev server reads THIS instead (E2E_HOMEPAGE_SUMMARY_FILE, app/lib/summary.ts,
// honoured only outside a production build): the real builder
// (buildHomepageSummary) over made-up recordings, deterministic, written by
// playwright.config.ts to e2e/.e2e-summary.json (gitignored, not linked) before
// the server starts. Nothing is read from public/ or from another checkout, and
// every spec that reads numbers reads this file.
//
// What the data is shaped to exercise:
//   • six public sites (the chart's six validated slots), in the order the
//     builder sorts them (transcripts, most first);
//   • their accents: a named accent (Brass), a PALE custom hex (fitted per
//     base on the cards, 1.43:1 on the light ground as published), three with
//     none, and Vermilion (the sixth slot's family);
//   • the first site dwarfs the rest, with one week of 12,000 transcripts in
//     May (the "megaspike", outside the six-week window), so /stats' All-time
//     symlog axis reaches 10K while the Recent weeks stay linear and small;
//   • every site transcribes every day of the last 200, so every line is full
//     and every series has a non-zero start for Indexed;
//   • uploads spread over 2019–2026, for the growth chart's months;
//   • the last two sites each under 5 % of the growth chart's total (4.35 and
//     3.26 %), so the chart folds them into its Other band (release 14 slice
//     CF; fixture-five transcribes 4 a day, not 5, for it);
//   • a seventh site, UNLISTED (site.json `listed: false`, release 14 slice
//     HS): its own two channels transcribe every day like the rest, and it
//     also exposes the first site's first channel. The summary names it nowhere
//     and counts its own channels in no total, so `buildFixtureSummary()` is
//     exactly `buildFixtureSummary(FIXTURE_SITES, [])` — every number the specs
//     read is the six listed sites'. Every site in the second list is unlisted:
//     `buildFixtureInputs` sets `listed: false` on it, whatever it carries.

export const FIXTURE_SUMMARY_NAME = ".e2e-summary.json";

// "Now", for the builder: the build month (September 2026) is partial and is
// not charted; the week and day buckets end here.
export const FIXTURE_NOW = new Date("2026-09-15T12:00:00Z");

// A pale custom hex: published as is it would be a ghost on light.
export const FIXTURE_PALE_HEX = "#f4c2d7";

// The six sites, in summary order. `accent` is the site.json setting (an
// accent id or a custom hex), as compose reads it; `wordmarkLead` the
// site.json one (a named accent's site, the custom hex's and a site with no
// accent have one — the last ends MID-WORD, "Fix" + "ture Three", as
// "Jer" + "alyzer" does; the rest show their title plain); `daily` how many
// recordings each channel transcribes a day. Whether a site is listed is the
// list it is passed in (buildFixtureInputs), not a field.
export type FixtureSite = {
  siteId: string;
  siteTitle: string;
  accent?: string;
  wordmarkLead?: string;
  channels: number;
  daily: number;
};

export const FIXTURE_SITES: readonly FixtureSite[] = [
  { siteId: "fixture-one", siteTitle: "Fixture One", accent: "brass", wordmarkLead: "Fixture", channels: 4, daily: 15 },
  { siteId: "fixture-two", siteTitle: "Fixture Two", accent: FIXTURE_PALE_HEX, wordmarkLead: "Fixture", channels: 3, daily: 9 },
  { siteId: "fixture-three", siteTitle: "Fixture Three", wordmarkLead: "Fix", channels: 3, daily: 7 },
  { siteId: "fixture-four", siteTitle: "Fixture Four", channels: 2, daily: 8 },
  { siteId: "fixture-five", siteTitle: "Fixture Five", channels: 2, daily: 4 },
  { siteId: "fixture-six", siteTitle: "Fixture Six", accent: "vermilion", channels: 2, daily: 3 },
];

// The unlisted site (an invented id, as every fixture's). Not in FIXTURE_SITES,
// which is the six the pages show; buildFixtureInputs' second list, which
// unlists it.
export const FIXTURE_UNLISTED_SITE: FixtureSite = {
  siteId: "fixture-unlisted",
  siteTitle: "Fixture Unlisted",
  channels: 2,
  daily: 6,
};

const DAY = 86_400_000;
const SPIKE = { site: 0, start: Date.UTC(2026, 4, 11), days: 7, count: 12_000 };
const HISTORY_DAYS = 200;

const ymd = (t: number) => new Date(t).toISOString().slice(0, 10).replace(/-/g, "");

// A recording's upload date: spread over the 92 months before the build month,
// deterministically (a multiplicative walk over the index, so every site has
// uploads in most months).
function uploadDate(n: number): string {
  const back = 1 + ((n * 37) % 92); // months before September 2026
  const d = new Date(Date.UTC(2026, 8 - back, 1 + ((n * 11) % 28)));
  return ymd(d.getTime());
}

// The builder's inputs: the recordings, the channel → sites map and the sites.
// `fixtureSites` are listed; every site in `unlistedSites` is written with
// `listed: false`, and each also exposes the first listed site's first channel.
export function buildFixtureInputs(
  fixtureSites: readonly FixtureSite[] = FIXTURE_SITES,
  unlistedSites: readonly FixtureSite[] = [FIXTURE_UNLISTED_SITE],
): { stats: VideoStat[]; channelSites: Record<string, string[]>; sites: Site[] } {
  const stats: VideoStat[] = [];
  const channelSites: Record<string, string[]> = {};
  const sites: Site[] = [];
  let n = 0;
  const record = (siteIdx: number, slug: string, name: string, day: number) => {
    n += 1;
    stats.push({
      slug: `${slug}/v${n}`,
      id: `v${n}`,
      channelSlug: slug,
      channel: name,
      title: `Fixture recording ${n}`,
      platform: "youtube",
      uploadDate: uploadDate(n),
      downloadedDate: ymd(day),
      transcribedDate: ymd(day),
      timestamp: null,
      duration: 1200 + ((n * 97) % 5400),
      viewCount: null,
      likeCount: null,
      commentCount: null,
      channelFollowerCount: null,
      categories: [],
      tags: [],
      language: "en",
      isLivestream: false,
      mediaType: "video",
      // One in forty re-checked and found gone at the source.
      status: n % 40 === siteIdx ? "deleted" : "available",
      hasTranscript: true,
      cueCount: null,
      coverage: null,
    });
  };
  const today = Date.UTC(2026, 8, 15);
  // A site's own channels, `<siteId>-ch<N>`, each transcribing every day of the
  // last HISTORY_DAYS; `shared` are other sites' channels it also exposes.
  const addSite = (
    s: FixtureSite,
    i: number,
    { listed = true, shared = [] }: { listed?: boolean; shared?: string[] } = {},
  ) => {
    const slugs = Array.from({ length: s.channels }, (_, c) => `${s.siteId}-ch${c + 1}`);
    for (const slug of [...slugs, ...shared]) (channelSites[slug] ??= []).push(s.siteId);
    sites.push({
      siteId: s.siteId,
      siteTitle: s.siteTitle,
      siteDescription: `${s.siteTitle}, an e2e fixture archive.`,
      siteUrl: `https://${s.siteId}.example`,
      channels: [...slugs, ...shared].map((slug) => ({ slug })),
      ...(s.accent ? { accent: s.accent } : {}),
      ...(s.wordmarkLead ? { wordmarkLead: s.wordmarkLead } : {}),
      ...(listed ? {} : { listed: false }),
    } as unknown as Site);
    slugs.forEach((slug, c) => {
      const name = `${s.siteTitle} Channel ${c + 1}`;
      for (let d = 0; d < HISTORY_DAYS; d++) {
        const day = today - d * DAY;
        // A little day-to-day rhythm, never zero.
        const count = Math.max(1, s.daily - c * 2 + ((d + c) % 3));
        for (let k = 0; k < count; k++) record(i, slug, name, day);
      }
    });
  };
  fixtureSites.forEach((s, i) => addSite(s, i));
  // The megaspike: one week of bulk transcription on the first site's first
  // channel.
  const spikeSite = fixtureSites[SPIKE.site];
  for (let k = 0; k < SPIKE.count; k++) {
    record(SPIKE.site, `${spikeSite.siteId}-ch1`, `${spikeSite.siteTitle} Channel 1`, SPIKE.start + (k % SPIKE.days) * DAY);
  }
  // The unlisted sites LAST, so every listed site's recordings (their numbers,
  // dates and states) are the same with them or without.
  unlistedSites.forEach((s, j) =>
    addSite(s, fixtureSites.length + j, {
      listed: false,
      shared: [`${spikeSite.siteId}-ch1`],
    }),
  );
  return { stats, channelSites, sites };
}

// The summary the e2e dev server reads: the real builder over those inputs.
export function buildFixtureSummary(
  fixtureSites: readonly FixtureSite[] = FIXTURE_SITES,
  unlistedSites: readonly FixtureSite[] = [FIXTURE_UNLISTED_SITE],
) {
  const { stats, channelSites, sites } = buildFixtureInputs(fixtureSites, unlistedSites);
  return buildHomepageSummary(stats, channelSites, sites, FIXTURE_NOW);
}

// Write the fixture summary to `dest`. The write is a rename, because
// Playwright evaluates its config again in every worker it starts, while the
// dev server may be reading the file.
export function writeFixtureSummary(dest: string): void {
  const tmp = `${dest}.${process.pid}.tmp`;
  fs.writeFileSync(tmp, JSON.stringify(buildFixtureSummary()));
  fs.renameSync(tmp, dest);
}