// ========= Copyright 2026 @ Strukto.AI All Rights Reserved. =========
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ========= Copyright 2026 @ Strukto.AI All Rights Reserved. =========

import { randomBytes } from "node:crypto";
import { gzipSync } from "node:zlib";
import { ChromaClient } from "chromadb";
import { ChromaResource, MountMode, Workspace } from "@struktoai/mirage-node";
import { runNotFound, runProvisionProbe, runSedReadonlyProbe } from "./cases.ts";

const CHROMA_HOST = process.env.CHROMA_HOST ?? "localhost";
const CHROMA_PORT = Number.parseInt(process.env.CHROMA_PORT ?? "8000", 10);
const EMBED_DIM = 8;
const MOUNT = "/knowledge/";

const DEC = new TextDecoder();

const PATH_TREE: Record<string, Record<string, unknown>> = {
  "guides/quickstart.md": {
    size: 180,
    created_at: "2026-01-01T00:00:00Z",
    updated_at: "2026-02-01T00:00:00Z",
  },
  "guides/auth.md": {
    size: 190,
    created_at: "2026-01-15T00:00:00Z",
    updated_at: "2026-02-15T00:00:00Z",
  },
  "policies/refunds.md": {
    size: 150,
    created_at: "2026-02-01T00:00:00Z",
    updated_at: "2026-03-01T00:00:00Z",
  },
  "policies/privacy.md": {
    size: 120,
    created_at: "2026-02-10T00:00:00Z",
    updated_at: "2026-03-10T00:00:00Z",
  },
  "CHANGELOG.md": {
    size: 90,
  },
};

interface SeedChunk {
  document: string;
  metadata: { page_slug: string; chunk_index: number };
}

const CHUNKS: Record<string, SeedChunk[]> = {
  "guides/quickstart.md": [
    {
      document: "Welcome to Acme. This quickstart gets you running fast.",
      metadata: { page_slug: "guides/quickstart.md", chunk_index: 0 },
    },
    {
      document: "Install the CLI with npm i -g acme then run acme login.",
      metadata: { page_slug: "guides/quickstart.md", chunk_index: 1 },
    },
    {
      document: "Set your token in the ACME_TOKEN environment variable.",
      metadata: { page_slug: "guides/quickstart.md", chunk_index: 2 },
    },
  ],
  "guides/auth.md": [
    {
      document:
        "Authentication uses bearer tokens via the Authorization header.",
      metadata: { page_slug: "guides/auth.md", chunk_index: 0 },
    },
    {
      document: "Requests are rate limited to 100 calls per minute per token.",
      metadata: { page_slug: "guides/auth.md", chunk_index: 1 },
    },
    {
      document:
        "If you exceed the limit you receive HTTP 429 and must back off.",
      metadata: { page_slug: "guides/auth.md", chunk_index: 2 },
    },
  ],
  "policies/refunds.md": [
    {
      document: "Refunds are available within 30 days of purchase.",
      metadata: { page_slug: "policies/refunds.md", chunk_index: 0 },
    },
    {
      document: "Email support to start a refund with your order id.",
      metadata: { page_slug: "policies/refunds.md", chunk_index: 1 },
    },
    {
      document: "Approved refunds are processed within five business days.",
      metadata: { page_slug: "policies/refunds.md", chunk_index: 2 },
    },
  ],
  "policies/privacy.md": [
    {
      document: "Customer data is stored encrypted at rest and in transit.",
      metadata: { page_slug: "policies/privacy.md", chunk_index: 0 },
    },
    {
      document: "We never sell personal information to third parties.",
      metadata: { page_slug: "policies/privacy.md", chunk_index: 1 },
    },
  ],
  "CHANGELOG.md": [
    {
      document: "v2.0 added rate limit headers and refund automation.",
      metadata: { page_slug: "CHANGELOG.md", chunk_index: 0 },
    },
  ],
};

const CASES: ReadonlyArray<readonly [string, string]> = [
  ["ls", "ls {root}"],
  ["ls_guides", "ls {root}guides/"],
  ["tree", "tree {root}"],
  ["find_md", "find {root} -name '*.md'"],
  ["find_type_f", "find {root} -type f | sort"],
  ["find_root_maxdepth0", "find {root} -maxdepth 0"],
  ["find_root_name", "find {root} -name knowledge"],
  // cold (bespoke) then warm (cache-mount generic) must be identical
  ["grep_cold_single", "grep bearer {root}guides/auth.md"],
  ["grep_warm_single", "grep bearer {root}guides/auth.md"],
  ["cat_auth", "cat {root}guides/auth.md"],
  ["cat_quickstart", "cat {root}guides/quickstart.md"],
  ["head_1", "head -n 1 {root}guides/quickstart.md"],
  ["tail_1", "tail -n 1 {root}guides/quickstart.md"],
  ["grep_429", "grep 429 {root}guides/auth.md"],
  ["grep_e_multi", "grep -e bearer -e 429 {root}guides/auth.md"],
  ["grep_c_rate", "grep -c rate {root}guides/auth.md"],
  ["grep_r_refund", "grep -r refund {root}policies/"],
  ["grep_cold_count", "grep -c sell {root}policies/privacy.md"],
  ["grep_warm_count", "grep -c sell {root}policies/privacy.md"],
  ["grep_rl_encrypted", "grep -rl encrypted {root}"],
  ["grep_v_bearer", "grep -v bearer {root}guides/auth.md"],
  ["grep_rE_alternation", 'grep -rE "rate limited|refund" {root}'],
  ["wc_l_auth", "wc -l {root}guides/auth.md"],
  ["sort_auth", "sort {root}guides/auth.md"],
  ["uniq_auth", "uniq {root}guides/auth.md"],
  ["uniq_w0_auth", "uniq -w 0 {root}guides/auth.md"],
  ["stat_name_auth", 'stat -c "%n" {root}guides/auth.md'],
  ["cut_d_f1", "cut -d ' ' -f 1 {root}guides/quickstart.md"],
  ["awk_first_word", "awk '{print $1}' {root}guides/quickstart.md"],
  ["sed_upper_acme", "sed s/Acme/ACME/ {root}guides/quickstart.md"],
  ["rg_l_token", "rg -l token {root}"],
  ["pipe_cat_wc", "cat {root}guides/auth.md | wc -l"],
  ["pipe_sort_uniq_wc", "cat {root}policies/refunds.md | sort | uniq | wc -l"],
  // cat cache poisoning: per-file cache keys after a concat cat
  ["poison_concat", "cat {root}guides/quickstart.md {root}guides/auth.md"],
  ["poison_first_intact", "cat {root}guides/quickstart.md"],
  ["poison_second_intact", "cat {root}guides/auth.md"],
  [
    "pipe_concat_head",
    "cat {root}guides/quickstart.md {root}guides/auth.md | head -n 1",
  ],
  // du has no native op -> exercises the stat/readdir walk fallback,
  // which must match the Python du builder byte for byte.
  ["du_guides", "du {root}guides"],
  ["du_root", "du {root}"],
  ["du_c_multi", "du -c {root}guides {root}policies"],
  // symlink into the mount: links are namespace state, so they work on a
  // read-only backend (no backend write happens)
  ["sym_ln", "ln -s {root}guides/auth.md {root}meta_link"],
  ["sym_readlink", "readlink {root}meta_link"],
  ["sym_cat", "cat {root}meta_link"],
  ["sym_wc", "wc -l {root}meta_link"],
  ["sym_ls", "ls -F {root} | grep meta_link"],
  ["sym_rm", "rm {root}meta_link && ls {root}"],
];

function encodedPathTree(): string {
  // gzip+base64 variant so the integ covers parsePathTree's
  // encoded branch (unit tests cover the plain JSON branch)
  return gzipSync(Buffer.from(JSON.stringify(PATH_TREE))).toString("base64");
}

function embeddingFor(position: number): number[] {
  const vector = new Array<number>(EMBED_DIM).fill(0);
  vector[position % EMBED_DIM] = 1;
  return vector;
}

async function seedCollection(collectionName: string): Promise<void> {
  const client = new ChromaClient({ host: CHROMA_HOST, port: CHROMA_PORT });
  const collection = await client.createCollection({
    name: collectionName,
    embeddingFunction: null,
  });
  const ids = ["__path_tree__"];
  const documents = [encodedPathTree()];
  const metadatas: Record<string, string | number>[] = [{ kind: "path_tree" }];
  const embeddings = [embeddingFor(0)];
  let position = 1;
  for (const chunks of Object.values(CHUNKS)) {
    for (const chunk of chunks) {
      const slug = chunk.metadata.page_slug;
      const index = chunk.metadata.chunk_index;
      ids.push(`${slug}#${String(index)}`);
      documents.push(chunk.document);
      metadatas.push(chunk.metadata);
      embeddings.push(embeddingFor(position));
      position += 1;
    }
  }
  await collection.add({ ids, documents, metadatas, embeddings });
}

async function runCase(
  ws: Workspace,
  name: string,
  cmd: string,
): Promise<void> {
  const result = await ws.execute(cmd);
  const out = DEC.decode(result.stdout);
  process.stdout.write(`=== ${name} ===\n`);
  process.stdout.write(out.endsWith("\n") ? out : out + "\n");
}

async function main(): Promise<void> {
  const collectionName = `mirage-integ-${randomBytes(4).toString("hex")}`;
  await seedCollection(collectionName);
  const ws = new Workspace(
    {
      [MOUNT]: new ChromaResource({
        host: CHROMA_HOST,
        port: CHROMA_PORT,
        collectionName,
      }),
    },
    { mode: MountMode.READ },
  );
  // Vector search (the `chroma-query` command) is not exercised here: the
  // thin client ships no embedding function for queryTexts. It is covered
  // by unit tests (src/core/chroma and src/util/score tests).
  try {
    for (const [name, tmpl] of CASES) {
      await runCase(ws, name, tmpl.replaceAll("{root}", MOUNT));
    }
    await runNotFound(ws, MOUNT);
    await runProvisionProbe(ws, `${MOUNT}guides/auth.md`);
    await runSedReadonlyProbe(ws, `${MOUNT}guides/auth.md`);
  } finally {
    await ws.close();
  }
}

main().catch((err: unknown) => {
  process.stderr.write(String(err) + "\n");
  process.exit(1);
});