import { test } from "node:test";
import assert from "node:assert/strict";
import { mkdtempSync, writeFileSync, mkdirSync, rmSync } from "node:fs";
import { join } from "node:path";
import { tmpdir } from "node:os";

import {
  docLabel,
  relativeLink,
  canonicalDocPath,
  parseMetadata,
  renderMetadata,
  renderBacklog,
  validateLinks,
  serializeTicketFile,
} from "../src/utils.ts";
import type { DocMetadata, Ticket } from "../src/types.ts";

const META_BASE: DocMetadata = {
  purpose: "p",
  audience: "Both",
  sourceOfTruth: "Codebase (implementation is authoritative)",
  lastUpdated: "2026-01-01",
  dependsOn: [],
  referencedBy: [],
};

function sampleTicket(overrides: Partial<Ticket> = {}): Ticket {
  return {
    id: "001",
    title: "Foo",
    status: "backlog",
    priority: "P2",
    dependencies: [],
    context: "",
    acceptanceCriteria: [],
    definitionOfDone: [],
    implementationNotes: [],
    relatedDocs: [],
    relatedFiles: [],
    createdAt: "2026-01-01T00:00:00.000Z",
    updatedAt: "2026-01-01T00:00:00.000Z",
    ...overrides,
  };
}

// ── docLabel ───────────────────────────────────────────────────────────

test("docLabel strips directory and .md extension", () => {
  assert.equal(docLabel("docs/SPEC.md"), "SPEC");
  assert.equal(docLabel("AGENTS.md"), "AGENTS");
  assert.equal(docLabel("docs/tickets/"), "tickets");
  assert.equal(docLabel("T-001-foo.md"), "T-001-foo");
});

// ── relativeLink ───────────────────────────────────────────────────────

test("relativeLink is computed from the source file, not hardcoded", () => {
  // The canonical examples from the spec:
  // docs/ARCHITECTURE.md -> docs/SPEC.md must be SPEC.md
  assert.equal(relativeLink("docs/ARCHITECTURE.md", "docs/SPEC.md"), "SPEC.md");
  // README.md -> docs/SPEC.md stays docs/SPEC.md
  assert.equal(relativeLink("README.md", "docs/SPEC.md"), "docs/SPEC.md");

  // Sibling docs inside docs/ never carry a docs/ prefix
  assert.equal(relativeLink("docs/API.md", "docs/SPEC.md"), "SPEC.md");
  assert.equal(relativeLink("docs/SPEC.md", "docs/ARCHITECTURE.md"), "ARCHITECTURE.md");
  // Docs leaving their directory climb with ..
  assert.equal(relativeLink("docs/SPEC.md", "AGENTS.md"), "../AGENTS.md");
  // Root docs link to root docs without prefix
  assert.equal(relativeLink("AGENTS.md", "README.md"), "README.md");
  // Directory targets
  assert.equal(relativeLink("docs/BACKLOG.md", "docs/tickets"), "tickets");
  assert.equal(relativeLink("AGENTS.md", "docs/tickets"), "docs/tickets");
});

// ── canonicalDocPath ───────────────────────────────────────────────────

test("canonicalDocPath resolves hrefs relative to their containing file", () => {
  assert.equal(canonicalDocPath("docs/ARCHITECTURE.md", "SPEC.md"), "docs/SPEC.md");
  assert.equal(canonicalDocPath("README.md", "docs/SPEC.md"), "docs/SPEC.md");
  assert.equal(canonicalDocPath("docs/SPEC.md", "../AGENTS.md"), "AGENTS.md");
  assert.equal(
    canonicalDocPath("docs/BACKLOG.md", "tickets/T-001.md"),
    "docs/tickets/T-001.md",
  );
});

test("relativeLink and canonicalDocPath round-trip", () => {
  const source = "docs/ARCHITECTURE.md";
  const target = "docs/SPEC.md";
  const href = relativeLink(source, target);
  assert.equal(canonicalDocPath(source, href), target);
});

// ── parseMetadata / renderMetadata ─────────────────────────────────────

test("renderMetadata renders links relative to the source document", () => {
  const rendered = renderMetadata(
    {
      ...META_BASE,
      dependsOn: ["docs/SPEC.md", "docs/API.md"],
      referencedBy: ["AGENTS.md", "docs/BACKLOG.md"],
    },
    "docs/ARCHITECTURE.md",
  );
  assert.match(rendered, /\[SPEC\]\(SPEC\.md\)/);
  assert.match(rendered, /\[API\]\(API\.md\)/);
  assert.match(rendered, /\[AGENTS\]\(\.\.\/AGENTS\.md\)/);
  assert.match(rendered, /\[BACKLOG\]\(BACKLOG\.md\)/);
});

test("renderMetadata keeps docs/SPEC.md href for root-level documents", () => {
  const rendered = renderMetadata(
    { ...META_BASE, dependsOn: ["docs/SPEC.md"] },
    "README.md",
  );
  assert.match(rendered, /\[SPEC\]\(docs\/SPEC\.md\)/);
});

test("parseMetadata canonicalizes hrefs and round-trips through renderMetadata", () => {
  const source = "docs/ARCHITECTURE.md";
  const rendered = renderMetadata(
    { ...META_BASE, dependsOn: ["docs/SPEC.md"], referencedBy: ["AGENTS.md"] },
    source,
  );
  const parsed = parseMetadata(rendered, source);
  assert.deepEqual(parsed.dependsOn, ["docs/SPEC.md"]);
  assert.deepEqual(parsed.referencedBy, ["AGENTS.md"]);

  // Re-rendering the parsed metadata from a different file still resolves
  const fromRoot = renderMetadata(parsed, "README.md");
  assert.match(fromRoot, /\[SPEC\]\(docs\/SPEC\.md\)/);
  assert.match(fromRoot, /\[AGENTS\]\(AGENTS\.md\)/);
});

// ── renderBacklog ──────────────────────────────────────────────────────

test("renderBacklog links everything relative to docs/BACKLOG.md", () => {
  const backlog = renderBacklog([
    sampleTicket({ title: "Add dark mode" }),
  ]);
  assert.match(backlog, /\[ROADMAP\]\(ROADMAP\.md\)/);
  assert.match(backlog, /\[AGENTS\]\(\.\.\/AGENTS\.md\)/);
  assert.match(backlog, /\[`tickets\/`\]\(tickets\/\)/);
  assert.match(backlog, /\[T-001-add-dark-mode\.md\]\(tickets\/T-001-add-dark-mode\.md\)/);

  // No root-relative docs/ hrefs may leak into docs/BACKLOG.md
  assert.doesNotMatch(backlog, /\]\(docs\//);
});

// ── serializeTicketFile ────────────────────────────────────────────────

test("serializeTicketFile renders relatedDocs relative to the ticket file", () => {
  const ticket = sampleTicket({ relatedDocs: ["docs/API.md", "docs/DESIGN.md"] });
  const out = serializeTicketFile(ticket);
  assert.match(out, /\[API\]\(\.\.\/API\.md\)/);
  assert.match(out, /\[DESIGN\]\(\.\.\/DESIGN\.md\)/);
});

test("serializeTicketFile preserves checkbox state and inline verification comments", () => {
  const ticket = sampleTicket({
    acceptanceCriteria: [
      {
        text: "pnpm dev serves a page at localhost:3000",
        checked: true,
        comment: "VERIFIED: served HTTP 200",
      },
      { text: "pnpm typecheck passes", checked: false, comment: "" },
    ],
    definitionOfDone: [{ text: "Test written first", checked: true, comment: "" }],
  });
  const out = serializeTicketFile(ticket);
  // Checked boxes render as [x], comments stay inline on the same line.
  assert.match(out, /- \[x\] pnpm dev serves a page at localhost:3000 <\!-- VERIFIED: served HTTP 200 -->/);
  assert.match(out, /- \[ \] pnpm typecheck passes/);
  assert.match(out, /- \[x\] Test written first/);
  // No comment is stranded on its own line / as its own checkbox.
  assert.doesNotMatch(out, /- \[ \] <!--|- \[x\] <!--/);
});

// ── validateLinks ──────────────────────────────────────────────────────

test("validateLinks resolves hrefs relative to the source document's directory", () => {
  const dir = mkdtempSync(join(tmpdir(), "docgraph-validate-"));
  try {
    mkdirSync(join(dir, "docs"));
    mkdirSync(join(dir, "docs", "tickets"));
    writeFileSync(join(dir, "docs", "SPEC.md"), "spec");
    writeFileSync(join(dir, "AGENTS.md"), "agents");
    writeFileSync(join(dir, "docs", "tickets", "filler"), "");

    // Relative hrefs from docs/ARCHITECTURE.md resolve inside docs/
    const ok = validateLinks(
      "[SPEC](SPEC.md) and [AGENTS](../AGENTS.md)",
      "docs/ARCHITECTURE.md",
      dir,
    );
    assert.equal(ok.valid, true, JSON.stringify(ok.broken));

    // Missing target is reported
    const missing = validateLinks("[NOPE](NOPE.md)", "docs/ARCHITECTURE.md", dir);
    assert.deepEqual(missing.broken, ["NOPE.md"]);

    // A root-relative docs/ href inside docs/* is genuinely broken
    const rootHref = validateLinks(
      "[SPEC](docs/SPEC.md)",
      "docs/ARCHITECTURE.md",
      dir,
    );
    assert.equal(rootHref.valid, false);

    // Root-level docs resolve against the repo root
    const fromRoot = validateLinks("[SPEC](docs/SPEC.md)", "README.md", dir);
    assert.equal(fromRoot.valid, true, JSON.stringify(fromRoot.broken));

    // External and anchor links are skipped
    const external = validateLinks(
      "[x](https://example.com) [y](#section) [z](mailto:a@b.c)",
      "README.md",
      dir,
    );
    assert.equal(external.valid, true);
  } finally {
    rmSync(dir, { recursive: true, force: true });
  }
});