import { assertEquals } from "@std/assert";
import env from "@/env.ts";
import {
  normalize,
  readBuildInfoFrom,
  resolveGitShaFrom,
} from "@/lib/build-info.ts";

if (env.ENV !== "test") {
  throw new Error("ENV must be 'test'");
}

Deno.test("normalize", async (t) => {
  await t.step("returns null for null/undefined", () => {
    assertEquals(normalize(null), null);
    assertEquals(normalize(undefined), null);
  });
  await t.step("returns null for empty/whitespace", () => {
    assertEquals(normalize(""), null);
    assertEquals(normalize("   "), null);
    assertEquals(normalize("\t\n  "), null);
  });
  await t.step("trims and returns valid strings", () => {
    assertEquals(normalize("abc"), "abc");
    assertEquals(normalize("  abc  "), "abc");
    assertEquals(normalize("\tabc\n"), "abc");
  });
});

Deno.test("resolveGitShaFrom", async (t) => {
  await t.step("env var wins over baked value", () => {
    assertEquals(resolveGitShaFrom("env-sha", "baked-sha"), "env-sha");
  });
  await t.step("trims env var before precedence check", () => {
    assertEquals(resolveGitShaFrom("  env-sha  ", "baked-sha"), "env-sha");
  });
  await t.step("falls through to baked when env is unset/empty", () => {
    assertEquals(resolveGitShaFrom(undefined, "baked-sha"), "baked-sha");
    assertEquals(resolveGitShaFrom(null, "baked-sha"), "baked-sha");
    assertEquals(resolveGitShaFrom("", "baked-sha"), "baked-sha");
    assertEquals(resolveGitShaFrom("   ", "baked-sha"), "baked-sha");
  });
  await t.step("returns null when both unset", () => {
    assertEquals(resolveGitShaFrom(undefined, null), null);
    assertEquals(resolveGitShaFrom("", null), null);
    assertEquals(resolveGitShaFrom("   ", null), null);
  });
});

Deno.test("readBuildInfoFrom", async (t) => {
  const tempDir = await Deno.makeTempDir({ prefix: "build-info-test-" });
  const pathFor = (name: string) => `${tempDir}/${name}`;

  try {
    await t.step("returns nulls when file is missing", () => {
      assertEquals(readBuildInfoFrom(pathFor("nonexistent")), {
        commitSha: null,
        builtAt: null,
      });
    });

    await t.step("returns nulls for empty file", async () => {
      const path = pathFor("empty");
      await Deno.writeTextFile(path, "");
      assertEquals(readBuildInfoFrom(path), {
        commitSha: null,
        builtAt: null,
      });
    });

    await t.step("returns nulls for whitespace-only file", async () => {
      const path = pathFor("whitespace");
      await Deno.writeTextFile(path, "   \n   ");
      assertEquals(readBuildInfoFrom(path), {
        commitSha: null,
        builtAt: null,
      });
    });

    await t.step("returns nulls for malformed JSON", async () => {
      const path = pathFor("malformed");
      await Deno.writeTextFile(path, "{not json");
      assertEquals(readBuildInfoFrom(path), {
        commitSha: null,
        builtAt: null,
      });
    });

    await t.step("returns nulls for JSON null", async () => {
      const path = pathFor("null-literal");
      await Deno.writeTextFile(path, "null");
      assertEquals(readBuildInfoFrom(path), {
        commitSha: null,
        builtAt: null,
      });
    });

    await t.step("returns nulls for non-object JSON (string)", async () => {
      const path = pathFor("string-literal");
      await Deno.writeTextFile(path, '"abc"');
      assertEquals(readBuildInfoFrom(path), {
        commitSha: null,
        builtAt: null,
      });
    });

    await t.step("parses valid JSON and trims fields", async () => {
      const path = pathFor("valid");
      await Deno.writeTextFile(
        path,
        JSON.stringify({
          commitSha: "  abc123  ",
          builtAt: "2026-05-07T00:00:00Z",
        }),
      );
      assertEquals(readBuildInfoFrom(path), {
        commitSha: "abc123",
        builtAt: "2026-05-07T00:00:00Z",
      });
    });

    await t.step("normalizes empty string fields to null", async () => {
      const path = pathFor("empty-fields");
      await Deno.writeTextFile(
        path,
        JSON.stringify({ commitSha: "", builtAt: "  " }),
      );
      assertEquals(readBuildInfoFrom(path), {
        commitSha: null,
        builtAt: null,
      });
    });

    await t.step("handles missing fields", async () => {
      const path = pathFor("missing");
      await Deno.writeTextFile(path, "{}");
      assertEquals(readBuildInfoFrom(path), {
        commitSha: null,
        builtAt: null,
      });
    });

    await t.step("ignores extra fields", async () => {
      const path = pathFor("extras");
      await Deno.writeTextFile(
        path,
        JSON.stringify({ commitSha: "abc", builtAt: "now", extra: "x" }),
      );
      assertEquals(readBuildInfoFrom(path), {
        commitSha: "abc",
        builtAt: "now",
      });
    });
  } finally {
    await Deno.remove(tempDir, { recursive: true });
  }
});