/**
 * @file Tests for server/lib/lane-sync.js against a REAL git fixture: a bare
 * "origin", a lane clone, and a second clone acting as another lane that
 * pushes to origin/development independently. Mirrors the fixture shape of
 * Shipyard's own lane-sync-dev.sh test (test_sync_dev.sh) — collision
 * detection, clean merges, and conflicts are git's own behavior, so a mocked
 * git would only test our idea of git.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { describe, it, before, after, beforeEach } = require("node:test");
const assert = require("node:assert/strict");
const fs = require("node:fs");
const os = require("node:os");
const path = require("node:path");
const { execFileSync } = require("node:child_process");

const ROOT = fs.mkdtempSync(path.join(os.tmpdir(), "ccam-sync-"));

const laneSync = require("../lib/lane-sync");

const ORIGIN = path.join(ROOT, "origin.git");
const LANE_DIR = path.join(ROOT, "lane");
const PUSHER_DIR = path.join(ROOT, "pusher");

const g = (cwd, ...args) => {
  const env = { ...process.env };
  delete env.GIT_DIR;
  delete env.GIT_WORK_TREE;
  delete env.GIT_INDEX_FILE;
  delete env.GIT_COMMON_DIR;
  delete env.GIT_OBJECT_DIRECTORY;
  delete env.GIT_ALTERNATE_OBJECT_DIRECTORIES;
  delete env.GIT_PREFIX;
  delete env.GIT_NAMESPACE;
  delete env.GIT_CONFIG_PARAMETERS;
  env.GIT_TERMINAL_PROMPT = "0";
  return execFileSync("git", args, { cwd, encoding: "utf8", env });
};
const gc = (cwd, ...args) => g(cwd, "-c", "user.email=t@h", "-c", "user.name=t", ...args);

function freshFixture() {
  fs.rmSync(ROOT, { recursive: true, force: true });
  fs.mkdirSync(ROOT, { recursive: true });
  g(ROOT, "init", "-q", "--bare", ORIGIN);

  const seed = path.join(ROOT, "seed");
  g(ROOT, "init", "-q", "-b", "development", seed);
  fs.mkdirSync(path.join(seed, "db", "migrations"), { recursive: true });
  fs.writeFileSync(path.join(seed, "db", "migrations", "001_init.sql"), "create table a;\n");
  fs.writeFileSync(path.join(seed, "README.md"), "hello\n");
  gc(seed, "add", "-A");
  gc(seed, "commit", "-qm", "init");
  gc(seed, "remote", "add", "origin", ORIGIN);
  gc(seed, "push", "-q", "origin", "development");
  g(ORIGIN, "symbolic-ref", "HEAD", "refs/heads/development");

  g(ROOT, "clone", "-q", ORIGIN, LANE_DIR);
  g(ROOT, "clone", "-q", ORIGIN, PUSHER_DIR);

  gc(LANE_DIR, "checkout", "-qb", "feat/thing");
}

function lane() {
  return { cwd: LANE_DIR };
}

function profile(over = {}) {
  return {
    env: { MIGRATIONS_DIR: "db/migrations", GENERATED_MERGE_PATHS: "" },
    generatedMergePaths: [],
    hooks: new Set(),
    ...over,
  };
}

before(freshFixture);
after(() => fs.rmSync(ROOT, { recursive: true, force: true }));

describe("lane-sync guards", () => {
  it("refuses to run on development or main", async () => {
    await assert.rejects(
      () => laneSync.checkSync(lane(), profile(), "development"),
      (e) => e.code === "EBADBRANCH" && /feature branch/.test(e.message)
    );
    await assert.rejects(() => laneSync.mergeSync(lane(), profile(), "main"), {
      code: "EBADBRANCH",
    });
  });

  it("refuses a branch that doesn't exist", async () => {
    await assert.rejects(() => laneSync.checkSync(lane(), profile(), "feat/nope"), {
      code: "EBADBRANCH",
    });
  });
});

describe("lane-sync --check: migration collision", () => {
  it("detects a collision and suggests the next free number", () => {
    fs.writeFileSync(path.join(LANE_DIR, "db", "migrations", "002_a.sql"), "create table x;\n");
    gc(LANE_DIR, "add", "-A");
    gc(LANE_DIR, "commit", "-qm", "feat: add x");

    fs.writeFileSync(path.join(PUSHER_DIR, "db", "migrations", "002_b.sql"), "create table y;\n");
    gc(PUSHER_DIR, "add", "-A");
    gc(PUSHER_DIR, "commit", "-qm", "other lane");
    gc(PUSHER_DIR, "push", "-q", "origin", "development");

    return laneSync.checkSync(lane(), profile(), "feat/thing").then((result) => {
      assert.equal(result.code, 5);
      assert.equal(result.collisions.length, 1);
      assert.match(result.collisions[0].file, /002_a\.sql$/);
      assert.match(result.collisions[0].suggestion, /^003_a\.sql$/);
    });
  });

  it("passes clean after the renumber and reports the upstream delta", async () => {
    gc(LANE_DIR, "mv", "db/migrations/002_a.sql", "db/migrations/003_a.sql");
    gc(LANE_DIR, "commit", "-qm", "renumber migration");

    const result = await laneSync.checkSync(lane(), profile(), "feat/thing");
    assert.equal(result.code, 0);
    assert.equal(result.devDelta.length, 1);
    assert.match(result.devDelta[0], /002_b\.sql$/);
    assert.deepEqual(result.overlap, []);
  });
});

describe("lane-sync merge: clean merge lands upstream on the feature branch", () => {
  it("merges origin/development into the feature branch as a merge commit", async () => {
    const result = await laneSync.mergeSync(lane(), profile(), "feat/thing");
    assert.equal(result.code, 0);
    assert.equal(g(LANE_DIR, "rev-parse", "--abbrev-ref", "HEAD").trim(), "feat/thing");
    assert.doesNotThrow(() => g(LANE_DIR, "rev-parse", "-q", "--verify", "HEAD^2"));
    assert.ok(fs.existsSync(path.join(LANE_DIR, "db", "migrations", "002_b.sql")));
  });
});

describe("lane-sync merge: generated-file merge driver + regen fold-in", () => {
  const GEN_DIR = path.join(ROOT, "gen-fixture");
  const GEN_ORIGIN = path.join(ROOT, "gen-origin.git");
  const GEN_LANE = path.join(ROOT, "gen-lane");
  const GEN_PUSHER = path.join(ROOT, "gen-pusher");

  before(() => {
    fs.mkdirSync(GEN_DIR, { recursive: true });
    g(GEN_DIR, "init", "-q", "--bare", GEN_ORIGIN);
    const seed = path.join(GEN_DIR, "seed");
    g(GEN_DIR, "init", "-q", "-b", "development", seed);
    fs.mkdirSync(path.join(seed, "api"), { recursive: true });
    fs.writeFileSync(path.join(seed, "api", "openapi.json"), '{"v":1}\n');
    gc(seed, "add", "-A");
    gc(seed, "commit", "-qm", "init");
    gc(seed, "remote", "add", "origin", GEN_ORIGIN);
    gc(seed, "push", "-q", "origin", "development");
    g(GEN_ORIGIN, "symbolic-ref", "HEAD", "refs/heads/development");

    g(GEN_DIR, "clone", "-q", GEN_ORIGIN, GEN_LANE);
    g(GEN_DIR, "clone", "-q", GEN_ORIGIN, GEN_PUSHER);
    gc(GEN_LANE, "checkout", "-qb", "feat/gen");

    // The lane's own change to the generated file (would conflict without
    // the keep-ours driver).
    fs.writeFileSync(path.join(GEN_LANE, "api", "openapi.json"), '{"v":2,"branch":"feat"}\n');
    gc(GEN_LANE, "add", "-A");
    gc(GEN_LANE, "commit", "-qm", "feat: touches the contract");

    // Upstream's own change to the same generated file.
    fs.writeFileSync(path.join(GEN_PUSHER, "api", "openapi.json"), '{"v":2,"branch":"dev"}\n');
    gc(GEN_PUSHER, "add", "-A");
    gc(GEN_PUSHER, "commit", "-qm", "dev: also touches the contract");
    gc(GEN_PUSHER, "push", "-q", "origin", "development");

    // A regen hook the fold-in step will run.
    const profileDir = path.join(GEN_LANE, ".ccam", "profile");
    fs.mkdirSync(path.join(profileDir, "hooks"), { recursive: true });
    fs.writeFileSync(path.join(profileDir, "profile.env"), "PORTS=api\n");
    fs.writeFileSync(
      path.join(profileDir, "hooks", "regen.sh"),
      '#!/usr/bin/env bash\nset -euo pipefail\necho \'{"v":3,"regenerated":true}\' > "$LANE_DIR/api/openapi.json"\n'
    );
    fs.chmodSync(path.join(profileDir, "hooks", "regen.sh"), 0o755);
  });

  function genProfile() {
    return {
      env: { MIGRATIONS_DIR: "", GENERATED_MERGE_PATHS: "api/openapi.json" },
      generatedMergePaths: ["api/openapi.json"],
      hooks: new Set(["regen"]),
      dir: path.join(GEN_LANE, ".ccam", "profile"),
    };
  }

  it("installs a keep-ours driver so the generated file never conflicts, then folds regen output into the merge commit", async () => {
    const result = await laneSync.mergeSync(
      { cwd: GEN_LANE, slot: 999, id: 999 },
      genProfile(),
      "feat/gen"
    );
    assert.equal(result.code, 0);
    const contents = fs.readFileSync(path.join(GEN_LANE, "api", "openapi.json"), "utf8");
    assert.match(contents, /"regenerated":true/);
    // The regen output landed IN the merge commit, not a separate one.
    assert.doesNotThrow(() => g(GEN_LANE, "rev-parse", "-q", "--verify", "HEAD^2"));
    const parents = g(GEN_LANE, "log", "-1", "--format=%P").trim().split(" ");
    assert.equal(parents.length, 2);
  });
});

describe("lane-sync merge: conflict is left in place, --continue finishes it", () => {
  it("exits with code 4 and leaves MERGE_HEAD in place on a real conflict", async () => {
    fs.writeFileSync(path.join(LANE_DIR, "README.md"), "feature words\n");
    gc(LANE_DIR, "add", "-A");
    gc(LANE_DIR, "commit", "-qm", "feat: readme");

    fs.writeFileSync(path.join(PUSHER_DIR, "README.md"), "upstream words\n");
    gc(PUSHER_DIR, "add", "-A");
    gc(PUSHER_DIR, "commit", "-qm", "other readme");
    gc(PUSHER_DIR, "push", "-q", "origin", "development");

    const result = await laneSync.mergeSync(lane(), profile(), "feat/thing");
    assert.equal(result.code, 4);
    assert.deepEqual(result.conflictedFiles, ["README.md"]);
    assert.ok(fs.existsSync(path.join(LANE_DIR, ".git", "MERGE_HEAD")));
  });

  it("--continue refuses while conflicts are unresolved", async () => {
    await assert.rejects(() => laneSync.continueSync(lane(), profile(), "feat/thing"), {
      code: "EUNRESOLVED",
    });
  });

  it("--continue refuses while the merge is resolved but not committed", async () => {
    fs.writeFileSync(path.join(LANE_DIR, "README.md"), "merged words\n");
    gc(LANE_DIR, "add", "README.md");
    await assert.rejects(() => laneSync.continueSync(lane(), profile(), "feat/thing"), {
      code: "EMERGEUNCOMMITTED",
    });
  });

  it("--continue finishes after the conflict is resolved and committed", async () => {
    gc(LANE_DIR, "commit", "-q", "--no-edit");
    const result = await laneSync.continueSync(lane(), profile(), "feat/thing");
    assert.equal(result.code, 0);
    assert.equal(g(LANE_DIR, "rev-parse", "--abbrev-ref", "HEAD").trim(), "feat/thing");
  });
});

describe("lane-sync merge: rerere auto-resolves a previously-seen conflict", () => {
  // Bug this guards: mergeSync's catch block used to check
  // `conflicted.length && MERGE_HEAD exists` before falling through to the
  // rerere-commit path — but a fully rerere-auto-resolved merge has ZERO
  // unmerged files (git already staged the resolution), so that condition
  // was always false and the code rethrew the raw git error instead of
  // committing. Fixed by checking MERGE_HEAD first, unconditionally.
  const RR_ROOT = path.join(ROOT, "rerere-fixture");
  const RR_ORIGIN = path.join(RR_ROOT, "origin.git");
  const RR_LANE = path.join(RR_ROOT, "lane");
  const RR_PUSHER = path.join(RR_ROOT, "pusher");

  before(() => {
    fs.mkdirSync(RR_ROOT, { recursive: true });
    g(RR_ROOT, "init", "-q", "--bare", RR_ORIGIN);

    const seed = path.join(RR_ROOT, "seed");
    g(RR_ROOT, "init", "-q", "-b", "development", seed);
    fs.writeFileSync(path.join(seed, "config.txt"), "base\n");
    gc(seed, "add", "-A");
    gc(seed, "commit", "-qm", "init");
    gc(seed, "remote", "add", "origin", RR_ORIGIN);
    gc(seed, "push", "-q", "origin", "development");
    g(RR_ORIGIN, "symbolic-ref", "HEAD", "refs/heads/development");

    g(RR_ROOT, "clone", "-q", RR_ORIGIN, RR_LANE);
    g(RR_ROOT, "clone", "-q", RR_ORIGIN, RR_PUSHER);
    gc(RR_LANE, "config", "rerere.enabled", "true");
    // autoUpdate is what stages a rerere-recognized resolution automatically —
    // without it, git restores the resolved CONTENT but still leaves the file
    // as "unmerged" (ls-files -u non-empty), so MERGE_HEAD + zero unmerged
    // files (the exact condition the fixed code branches on) never occurs.
    gc(RR_LANE, "config", "rerere.autoupdate", "true");

    const baseSha = g(RR_LANE, "rev-parse", "development").trim();

    // Upstream's side of the conflict — pushed once, applies to both rounds.
    fs.writeFileSync(path.join(RR_PUSHER, "config.txt"), "dev version\n");
    gc(RR_PUSHER, "add", "-A");
    gc(RR_PUSHER, "commit", "-qm", "dev edits config");
    gc(RR_PUSHER, "push", "-q", "origin", "development");
    gc(RR_LANE, "fetch", "-q", "origin");

    // Round 1 — teach rerere the resolution.
    gc(RR_LANE, "checkout", "-qb", "feat/rerere-teach", baseSha);
    fs.writeFileSync(path.join(RR_LANE, "config.txt"), "lane version\n");
    gc(RR_LANE, "add", "-A");
    gc(RR_LANE, "commit", "-qm", "lane edits config");
    let conflicted = false;
    try {
      gc(RR_LANE, "merge", "--no-edit", "origin/development");
    } catch {
      conflicted = true;
    }
    if (!conflicted) throw new Error("fixture bug: expected the teach-round merge to conflict");
    fs.writeFileSync(path.join(RR_LANE, "config.txt"), "resolved version\n");
    gc(RR_LANE, "add", "config.txt");
    gc(RR_LANE, "commit", "-q", "--no-edit");

    // Round 2 — the actual test branch: an IDENTICAL edit to config.txt from
    // the same base, so the conflict signature matches what rerere just
    // learned and git auto-applies the recorded resolution during the merge
    // this test's assertion drives.
    gc(RR_LANE, "checkout", "-qb", "feat/rerere-actual", baseSha);
    fs.writeFileSync(path.join(RR_LANE, "config.txt"), "lane version\n");
    gc(RR_LANE, "add", "-A");
    gc(RR_LANE, "commit", "-qm", "lane edits config (again)");
  });

  it("commits automatically instead of reporting a conflict", async () => {
    const result = await laneSync.mergeSync({ cwd: RR_LANE }, profile(), "feat/rerere-actual");
    assert.equal(result.code, 0);
    assert.equal(fs.readFileSync(path.join(RR_LANE, "config.txt"), "utf8"), "resolved version\n");
    assert.ok(!fs.existsSync(path.join(RR_LANE, ".git", "MERGE_HEAD")));
  });
});

describe("lane-sync against a real git-worktree lane", () => {
  it("resolves MERGE_HEAD and info/attributes correctly under git worktree add", async () => {
    const wt = require("../lib/worktree");
    const WT_ROOT = path.join(ROOT, "wt-fixture");
    fs.mkdirSync(WT_ROOT, { recursive: true });
    const src = path.join(WT_ROOT, "src");
    g(WT_ROOT, "init", "-q", "-b", "development", src);
    fs.writeFileSync(path.join(src, "README.md"), "hello\n");
    gc(src, "add", "-A");
    gc(src, "commit", "-qm", "init");
    gc(src, "remote", "add", "origin", src); // self-origin: fetch is a same-repo no-op, good enough here
    gc(src, "branch", "-f", "refs/remotes/origin/development", "development");

    const wtDir = path.join(WT_ROOT, "wt-lane");
    await wt.addWorktree({ sourceRepo: src, dir: wtDir, branch: "feat/wt", base: "development" });

    // Simulate upstream moving, so devDeltaReport / collisionCheck have
    // something to resolve against without a real remote. `src` is still on
    // "development" here — addWorktree only checks out feat/wt in the NEW
    // worktree dir; checking out feat/wt on src too would collide with the
    // worktree (git refuses the same branch checked out twice).
    fs.writeFileSync(path.join(src, "README.md"), "upstream change\n");
    gc(src, "add", "-A");
    gc(src, "commit", "-qm", "upstream");
    gc(src, "branch", "-f", "refs/remotes/origin/development", "development");

    const wtProfile = {
      env: { MIGRATIONS_DIR: "", GENERATED_MERGE_PATHS: "" },
      generatedMergePaths: [],
      hooks: new Set(),
    };
    const result = await laneSync.checkSync({ cwd: wtDir }, wtProfile, "feat/wt");
    assert.equal(result.code, 0);
    assert.equal(result.devDelta.length, 1);
  });
});