import { assert, assertEquals, assertRejects, assertStringIncludes } from "@std/assert";
import { BACKGROUND_CONTEXT as context } from "@earendil-works/chord/context";
import { getOrThrow } from "@earendil-works/pi-durable/env";
import { rootedEnvironment } from "@berry/api/testing.ts";
import { tempDir } from "@berry/util";
import { discover, MAX_SKILL_BYTES, parseSkill, readSkill } from "./catalog.ts";
import { hostEnvironment, writeSkill } from "./testing.ts";

Deno.test("discovery combines target project skills, host XDG skills, and target user skills in precedence order", async () => {
  await using root = await tempDir();
  const env = rootedEnvironment(root.path, {
    cwd: "/repo/packages/app",
    variables: { XDG_CONFIG_HOME: "/settings" },
  });
  const host = hostEnvironment(root.path, { XDG_CONFIG_HOME: `${root.path}/host-settings` });
  getOrThrow(await env.writeFile("/repo/.git", "gitdir: elsewhere", context));
  await writeSkill(env, "/repo/packages/app/.agents/skills", "review", "nearest");
  await writeSkill(env, "/repo/.agents/skills", "review", "repository");
  await writeSkill(host, `${root.path}/host-settings/berry/skills`, "review", "berry host");
  await writeSkill(host, `${root.path}/host-settings/berry/skills`, "release", "berry release");
  await writeSkill(env, "/settings/berry/skills", "remote-only", "ignored target configuration");
  await writeSkill(env, "/home/.agents/skills", "release", "shared release");
  await writeSkill(env, "/home/.agents/skills", "pdf", "shared pdf");
  await writeSkill(env, "/.agents/skills", "outside", "unrelated ancestor");

  const catalog = await discover(env, host, context);
  assertEquals(catalog.projectRoot, "/repo");
  assertEquals(catalog.skills.map(({ name }) => name), ["review", "release", "pdf"]);
  assertEquals(catalog.skills[0].directory, "/repo/packages/app/.agents/skills/review");
  assertEquals(catalog.skills[1].directory, `${root.path}/host-settings/berry/skills/release`);
  assertStringIncludes(catalog.diagnostics.join("\n"), "shadowed");

  const untrusted = await discover(env, host, context, []);
  assertEquals(untrusted.skills.find(({ name }) => name === "review")?.scope, "host");
  assertEquals(
    untrusted.skills.find(({ name }) => name === "review")?.directory,
    `${root.path}/host-settings/berry/skills/review`,
  );
});

Deno.test("outside a repository discovery stays at cwd and uses the host's default configuration", async () => {
  await using root = await tempDir();
  const env = rootedEnvironment(root.path, { cwd: "/work/app" });
  await writeSkill(env, "/work/app/.agents/skills", "here", "local");
  await writeSkill(env, "/work/.agents/skills", "ancestor", "unrelated");
  const host = hostEnvironment(root.path);
  await writeSkill(host, `${root.path}/.config/berry/skills`, "personal", "personal");
  await writeSkill(
    env,
    "/home/.config/berry/skills",
    "remote-only",
    "ignored target configuration",
  );
  assertEquals((await discover(env, host, context)).skills.map(({ name }) => name), [
    "here",
    "personal",
  ]);
});

Deno.test("discovery deduplicates symlinks and keeps resource paths relative to the skill directory", async () => {
  await using root = await tempDir();
  const env = rootedEnvironment(root.path, { cwd: "/repo" });
  const location = await writeSkill(env, "/repo/.agents/skills", "review", "linked instructions");
  await Deno.symlink(
    `${root.path}/repo/.agents/skills/review`,
    `${root.path}/repo/.agents/skills/review-alias`,
  );
  getOrThrow(await env.createDir("/home/.agents", { recursive: true }, context));
  await Deno.symlink(`${root.path}/repo/.agents/skills`, `${root.path}/home/.agents/skills`);
  const shared = "/repo/shared.md";
  getOrThrow(await env.renameFile(location, shared, context));
  await Deno.symlink(`${root.path}${shared}`, `${root.path}${location}`);

  const catalog = await discover(env, hostEnvironment(root.path), context);
  assertEquals(catalog.skills.length, 1);
  assertEquals(catalog.skills[0].directory, "/repo/.agents/skills/review");
  assert(!catalog.diagnostics.some((line) => line.includes("shadowed")));
});

Deno.test("malformed and oversized skills produce diagnostics without hiding valid skills", async () => {
  await using root = await tempDir();
  const env = rootedEnvironment(root.path, { cwd: "/repo" });
  getOrThrow(
    await env.writeFile("/repo/.agents/skills/broken/SKILL.md", "---\nname: [\n---\n", context),
  );
  const oversized = await writeSkill(
    env,
    "/repo/.agents/skills",
    "huge",
    "x".repeat(MAX_SKILL_BYTES),
  );
  await writeSkill(env, "/repo/.agents/skills", "n".repeat(65), "invalid name");
  await writeSkill(env, "/repo/.agents/skills", "valid", "instructions");
  const catalog = await discover(env, hostEnvironment(root.path), context);
  assertEquals(catalog.skills.map(({ name }) => name), ["valid"]);
  assertStringIncludes(catalog.diagnostics.join("\n"), "broken/SKILL.md");
  assertStringIncludes(catalog.diagnostics.join("\n"), "exceeds");
  assertStringIncludes(catalog.diagnostics.join("\n"), "at most 64");
  await assertRejects(() => readSkill(env, oversized, context), Error, "exceeds");
});

Deno.test("multiline YAML and optional metadata remain compatible with standard skills", () => {
  const content =
    "---\r\nname: release\r\ndescription: >-\r\n  Prepare a release:\r\n  verify the changelog.\r\nmetadata:\r\n  author: charlotte\r\nallowed-tools: Bash Read\r\n---\r\nHuman prose:  keep this spacing.\r\n";
  const parsed = parseSkill(content, "old-directory");
  assertEquals(parsed.description, "Prepare a release: verify the changelog.");
  assertStringIncludes(parsed.warnings.join("\n"), "old-directory");
});