import { gzipSync } from "node:zlib";
import { performance } from "node:perf_hooks";
import { build as bundle } from "esbuild";
import {
  createAssetFieldCatalog,
  createAssetIndex,
  createCanonicalAssetFileEntry,
  extractMarkdownFrontmatter,
  normalizeAssetFileDocument,
  serializeContentArtifact,
  verifyContentArtifact,
} from "../src/compiler.ts";
import { executeAssetQuery } from "../src/index.ts";
import { createScaleMarkdownFixture } from "../src/scale-fixture.ts";

const projectId = "scale-project";
const files = createScaleMarkdownFixture(1000);
const encoder = new TextEncoder();

const percentile = (samples, quantile) =>
  [...samples].sort((left, right) => left - right)[
    Math.min(samples.length - 1, Math.floor(samples.length * quantile))
  ];
const measure = async (iterations, operation) => {
  const samples = [];
  for (let index = 0; index < iterations; index += 1) {
    const startedAt = performance.now();
    await operation();
    samples.push(performance.now() - startedAt);
  }
  return {
    medianMs: Number(percentile(samples, 0.5).toFixed(3)),
    p95Ms: Number(percentile(samples, 0.95).toFixed(3)),
  };
};

let markdownReads = 0;
const deriveEntry = async (file, revision = `revision-${file.id}`) => {
  markdownReads += 1;
  const metadata = await extractMarkdownFrontmatter(file.source);
  return createCanonicalAssetFileEntry({
    projectId,
    document: normalizeAssetFileDocument({
      asset: {
        id: file.id,
        name: file.name,
        folderId: "blog",
        folderNames: ["blog"],
        mimeType: "text/markdown",
        size: encoder.encode(file.source).byteLength,
        revision,
        contentRef: file.name,
      },
      properties: metadata.properties,
      excerpt: `Deterministic excerpt for ${file.id}`,
    }),
  });
};

const initialStartedAt = performance.now();
const entries = [];
for (const file of files) {
  entries.push(await deriveEntry(file));
}
const catalog = await createAssetFieldCatalog(entries);
const initialBackfillMs = performance.now() - initialStartedAt;
const initialMarkdownReads = markdownReads;

const buildIndex = () => createAssetIndex({ projectId, entries });
const coldBuildStartedAt = performance.now();
const index = await buildIndex();
const coldBuildMs = performance.now() - coldBuildStartedAt;
const warmBuild = await measure(10, buildIndex);

markdownReads = 0;
const changedFile = {
  ...files[999],
  source: files[999].source.replace("Post 999", "Changed post 999"),
};
const incrementalStartedAt = performance.now();
await deriveEntry(changedFile, "revision-post-0999-v2");
const incrementalMs = performance.now() - incrementalStartedAt;

const serialized = serializeContentArtifact(index);
const indexBytes = encoder.encode(serialized);
const coldParseAndVerify = await measure(10, () =>
  verifyContentArtifact(JSON.parse(serialized))
);

const read = async (contentRef, range) => {
  const file = files.find(({ name }) => name === contentRef);
  if (file === undefined) {
    throw new Error("Scale fixture content is missing");
  }
  const bytes = encoder
    .encode(file.source)
    .subarray(
      range?.offset ?? 0,
      range === undefined ? undefined : range.offset + range.length
    );
  return {
    data: {
      async *[Symbol.asyncIterator]() {
        yield bytes;
      },
    },
  };
};
const listingQuery = {
  where: {
    all: [
      { field: ["extension"], operator: "eq", value: "md" },
      { field: ["properties", "locale"], operator: "eq", value: "en" },
    ],
  },
  sort: [
    { field: ["properties", "publishedAt"], direction: "desc" },
    { field: ["id"], direction: "asc" },
  ],
  limit: 20,
};
const detailQuery = {
  where: {
    all: [
      {
        field: ["properties", "slug"],
        operator: "eq",
        value: "post-999",
      },
    ],
  },
  limit: 1,
  content: { mode: "full" },
};
const warmListing = await measure(50, () =>
  executeAssetQuery({
    query: listingQuery,
    catalog: index.fieldCatalog,
    documents: index.documents,
  })
);
const detailAndHydration = await measure(50, () =>
  executeAssetQuery({
    query: detailQuery,
    catalog: index.fieldCatalog,
    documents: index.documents,
    read,
  })
);

const workerBundle = await bundle({
  entryPoints: [
    new URL("../src/published-runtime.ts", import.meta.url).pathname,
  ],
  bundle: true,
  format: "esm",
  minify: true,
  platform: "browser",
  target: "es2022",
  conditions: ["webstudio", "browser"],
  write: false,
});
const workerBytes = workerBundle.outputFiles[0].contents;
const memoryBefore = process.memoryUsage().heapUsed;
const retainedCopies = Array.from({ length: 10 }, () => JSON.parse(serialized));
const memoryAfter = process.memoryUsage().heapUsed;

const nearLimitEntries = entries.map((entry) =>
  createCanonicalAssetFileEntry({
    projectId,
    document: {
      ...entry.document,
      properties: {
        ...entry.document.properties,
        benchmarkPayload: "x".repeat(3000),
      },
    },
  })
);
const nearLimitIndex = await createAssetIndex({
  projectId,
  entries: nearLimitEntries,
});
const nearLimitSerialized = serializeContentArtifact(nearLimitIndex);
const nearLimitMemoryBefore = process.memoryUsage().heapUsed;
const nearLimitParsed = await verifyContentArtifact(
  JSON.parse(nearLimitSerialized)
);
const nearLimitMemoryAfter = process.memoryUsage().heapUsed;

const projectEntryTier = (entry, tier) => {
  const { excerpt, ...withoutExcerpt } = entry.document;
  return createCanonicalAssetFileEntry({
    projectId,
    metadataRequirements: {
      structuredProperties: tier === "metadata" || tier === "content",
      excerpt: tier === "excerpt" || tier === "content",
    },
    document: {
      ...withoutExcerpt,
      properties:
        tier === "metadata" || tier === "content"
          ? entry.document.properties
          : {},
      ...(tier === "excerpt" || tier === "content" ? { excerpt } : {}),
    },
  });
};

const benchmarkTierArtifacts = async (count) => {
  const selectedEntries = entries.slice(0, count);
  const tiers = {};
  for (const tier of ["base", "metadata", "excerpt", "content"]) {
    const tierIndex = await createAssetIndex({
      projectId,
      entries: selectedEntries.map((entry) => projectEntryTier(entry, tier)),
    });
    const bytes = encoder.encode(serializeContentArtifact(tierIndex));
    tiers[tier] = {
      objectReads: tier === "base" ? 0 : count,
      parserRuns: tier === "base" ? 0 : count,
      jsonBytes: bytes.byteLength,
      gzipBytes: gzipSync(bytes).byteLength,
    };
  }
  return {
    inactive: { objectReads: 0, parserRuns: 0, jsonBytes: 0, gzipBytes: 0 },
    ...tiers,
  };
};

const tierArtifacts = {
  assets350: await benchmarkTierArtifacts(350),
  assets1000: await benchmarkTierArtifacts(1000),
};

console.info(
  JSON.stringify(
    {
      fixture: {
        markdownFiles: files.length,
        indexedFiles: index.documents.length,
        dynamicFieldPaths: catalog.fields.length,
      },
      initialBackfill: {
        durationMs: Number(initialBackfillMs.toFixed(3)),
        markdownReads: initialMarkdownReads,
      },
      incrementalOneFile: {
        durationMs: Number(incrementalMs.toFixed(3)),
        markdownReads,
      },
      indexBuild: { coldMs: Number(coldBuildMs.toFixed(3)), warm: warmBuild },
      indexArtifact: {
        jsonBytes: indexBytes.byteLength,
        gzipBytes: gzipSync(indexBytes).byteLength,
        coldParseAndVerify,
        nearLimit: {
          jsonBytes: encoder.encode(nearLimitSerialized).byteLength,
          parseVerifyHeapDeltaBytes: Math.max(
            0,
            nearLimitMemoryAfter - nearLimitMemoryBefore
          ),
          documents: nearLimitParsed.documents.length,
        },
      },
      workerRuntime: {
        minifiedBundleBytes: workerBytes.byteLength,
        minifiedBundleGzipBytes: gzipSync(workerBytes).byteLength,
        warmListing,
        dynamicSlugAndFullHydration: detailAndHydration,
        parsedIndexHeapBytesPerCopyEstimate: Math.max(
          0,
          Math.round((memoryAfter - memoryBefore) / retainedCopies.length)
        ),
      },
      queryTiers: tierArtifacts,
    },
    null,
    2
  )
);