import { encode } from "@jridgewell/sourcemap-codec";
import { expect } from "@std/expect";
import { describe, it as test } from "@std/testing/bdd";
import {
  applicationArea,
  attributeGeneratedBytes,
  type BundleSourceMap,
  categoryForSource,
  dependencyName,
  groupSourceBytes,
  sourceLineKey,
} from "#scripts/bench/bundle-composition/model.ts";

const sourceMap = (
  sources: string[],
  lines: Parameters<typeof encode>[0],
): BundleSourceMap => ({ mappings: encode(lines), sources });

describe("bundle composition model", () => {
  test("attributes generated bytes and unmapped text", () => {
    const result = attributeGeneratedBytes(
      "abcde\nx",
      sourceMap(
        ["a.ts", "b.ts"],
        [
          [
            [0, 0, 0, 0],
            [4, 1, 2, 0],
          ],
        ],
      ),
    );

    expect(result.totalBytes).toBe(7);
    expect(result.bySource).toEqual([
      { bytes: 4, source: "a.ts" },
      { bytes: 2, source: "[unmapped]" },
      { bytes: 1, source: "b.ts" },
    ]);
    expect(result.bySourceLine.get(sourceLineKey("b.ts", 2))).toBe(1);
  });

  test("counts UTF-8 bytes from UTF-16 source-map columns", () => {
    const result = attributeGeneratedBytes(
      "éx",
      sourceMap(
        ["accent.ts", "plain.ts"],
        [
          [
            [0, 0, 0, 0],
            [1, 1, 0, 0],
          ],
        ],
      ),
    );

    expect(result.bySource).toEqual([
      { bytes: 2, source: "accent.ts" },
      { bytes: 1, source: "plain.ts" },
    ]);
  });

  test("attributes prefixes and unmapped segments", () => {
    const prefixed = attributeGeneratedBytes(
      "--abc",
      sourceMap(["mapped.ts"], [[[2, 0, 0, 0]]]),
    );
    const unmapped = attributeGeneratedBytes("raw", sourceMap([], [[[0]]]));

    expect(prefixed.bySource).toEqual([
      { bytes: 3, source: "mapped.ts" },
      { bytes: 2, source: "[unmapped]" },
    ]);
    expect(unmapped.bySource).toEqual([{ bytes: 3, source: "[unmapped]" }]);
  });

  test("rejects a mapping whose source is missing", () => {
    expect(() =>
      attributeGeneratedBytes("x", sourceMap([], [[[0, 2, 0, 0]]])),
    ).toThrow("Missing source-map source 2");
  });

  test("classifies production source families", () => {
    expect(categoryForSource("inline-jsquash-wasm:bytes.ts")).toBe(
      "Inlined WASM",
    );
    expect(categoryForSource("inline-assets:#routes/assets.ts")).toBe(
      "Inlined browser/static module",
    );
    expect(categoryForSource("../src/shared/db/client.ts")).toBe(
      "Application source",
    );
    expect(categoryForSource("https://jsr.io/@std/path/1.0.0/mod.ts")).toBe(
      "JSR dependencies",
    );
    expect(categoryForSource("cache/node_modules/stripe/index.js")).toBe(
      "npm dependencies",
    );
    expect(categoryForSource("[unmapped]")).toBe(
      "Build glue and generated code",
    );
  });

  test("extracts npm and JSR package names", () => {
    expect(dependencyName("cache/node_modules/@sentry/core/index.js")).toBe(
      "@sentry/core",
    );
    expect(dependencyName("https://jsr.io/@std/media-types/1.1.0/mod.ts")).toBe(
      "@std/media-types",
    );
    expect(dependencyName("cache/node_modules/stripe/index.js")).toBe("stripe");
    expect(dependencyName("https://jsr.io/@std")).toBeNull();
    expect(dependencyName("../src/shared/sentry.ts")).toBeNull();
  });

  test("groups every application family by its narrowest area", () => {
    const examples = [
      ["../src/shared/db/migrations.ts", "Database migrations"],
      ["../src/shared/db/migrations/one.ts", "Database migrations"],
      ["../src/locales/en/admin.json", "Locales"],
      ["../src/ui/templates/admin/page.tsx", "Admin templates"],
      ["../src/features/admin/page.ts", "Admin routes"],
      ["../src/ui/templates/public/page.tsx", "Public templates"],
      ["../src/features/public/order.ts", "Public routes"],
      ["../src/features/api/webhook.ts", "API routes and webhooks"],
      ["../src/shared/db/client.ts", "Shared database code"],
      ["../src/ui/templates/layout.tsx", "Shared UI templates"],
      ["../src/shared/currency.ts", "Shared domain and runtime"],
      ["../src/features/index.ts", "Other features and routing"],
      ["../src/edge.ts", "Entry and root modules"],
    ] as const;
    expect(examples.map(([source]) => applicationArea(source))).toEqual(
      examples.map(([, area]) => area),
    );
    expect(applicationArea("cache/node_modules/pkg/index.js")).toBeNull();
  });

  test("adds bytes sharing the same report name", () => {
    expect(
      groupSourceBytes(
        [
          { bytes: 3, source: "b-one" },
          { bytes: 4, source: "a-one" },
          { bytes: 6, source: "a-two" },
          { bytes: 3, source: "skip" },
        ],
        (source) => (source === "skip" ? null : source.slice(0, 1)),
      ),
    ).toEqual([
      { bytes: 10, source: "a" },
      { bytes: 3, source: "b" },
    ]);
  });
});