// The revision diff and change summary (lib/report/revisions.ts), over two
// versions of a small fact-check.
//
// Run with: node_modules/.bin/tsx --test lib/report/revisions.test.ts

import { test } from "node:test";
import assert from "node:assert/strict";
import type { Report } from "./schema";
import {
  claimChanges,
  reportChangeSummary,
  revisionCommitMessage,
  revisionSummaryOf,
  wordDiff,
  type DiffSegment,
} from "./revisions";

const side = (d: DiffSegment[], op: "old" | "new") =>
  d.filter((s) => s.op === "eq" || s.op === (op === "old" ? "del" : "ins")).map((s) => s.text).join("");

function v1(): Report {
  return {
    format: "archilyzer-report",
    version: 1,
    id: "demo",
    kind: "factcheck",
    title: "Checking a demo article",
    subtitle: "Three claims",
    published: "2026-03-01",
    citations: {
      c01: { kind: "video", channel: "demo-channel", id: "abc", start: 10, end: 20, quote: "The bridge opened in spring." },
      c02: { kind: "video", channel: "demo-channel", id: "abc", start: 30, end: 40, quote: "I was there." },
      c03: { kind: "page", url: "https://example.org/a", quote: "A page." },
    },
    sections: [
      {
        id: "s1",
        title: "The bridge",
        claims: [
          { id: "k1", title: "When it opened", text: "The bridge opened in 2018.", verdict: "PARTLY", findings: "He says [spring](cite:c01).", citations: ["c01"] },
          { id: "k2", text: "He was not there.", verdict: "CONTRADICTED", findings: "He [was](cite:c02).", citations: ["c02"] },
          { id: "k3", text: "A third claim.", verdict: "UNTESTABLE", citations: ["c03"] },
        ],
      },
    ],
  };
}

function v2(): Report {
  const r = v1();
  r.title = "Checking the demo article";
  r.series = "Demo checks";
  delete r.subtitle;
  const claims = r.sections[0].claims!;
  claims[0] = { ...claims[0], text: "The bridge opened in 2019.", verdict: "CORROBORATED" };
  claims[1] = { ...claims[1], findings: "He says he [was there](cite:c02)." };
  claims.splice(2, 1);
  claims.push({ id: "k4", title: "The mail", text: "The mail came late.", verdict: "NOT_FOUND", citations: ["c04"] });
  r.citations!.c02 = { ...r.citations!.c02, quote: "I was there for it." };
  delete r.citations!.c03;
  r.citations!.c04 = { kind: "page", url: "https://example.org/b", quote: "Another page." };
  return r;
}

test("wordDiff: equal text is one run; a replaced word reads old then new; each side reassembles", () => {
  assert.deepEqual(wordDiff("same words", "same words"), [{ op: "eq", text: "same words" }]);
  const d = wordDiff("The bridge opened in 2018.", "The bridge opened in 2019.");
  assert.deepEqual(d, [
    { op: "eq", text: "The bridge opened in " },
    { op: "del", text: "2018." },
    { op: "ins", text: "2019." },
  ]);
  const a = "one two three four five six";
  const b = "one 2 three four six seven";
  const d2 = wordDiff(a, b);
  assert.equal(side(d2, "old"), a);
  assert.equal(side(d2, "new"), b);
  assert.deepEqual(wordDiff("", "new text"), [{ op: "ins", text: "new text" }]);
  assert.deepEqual(wordDiff("old text", ""), [{ op: "del", text: "old text" }]);
});

test("claimChanges: edited fields with word diffs, added and removed claims", () => {
  const changes = claimChanges(v1(), v2());
  assert.deepEqual(
    changes.map((c) => [c.id, c.status, c.fields.map((f) => f.field)]),
    [
      ["k1", "edited", ["text", "verdict"]],
      ["k2", "edited", ["findings"]],
      ["k4", "added", ["title", "text", "verdict"]],
      ["k3", "removed", ["text", "verdict"]],
    ],
  );
  const verdict = changes[0].fields.find((f) => f.field === "verdict")!;
  assert.deepEqual(verdict.diff, [
    { op: "del", text: "PARTLY" },
    { op: "ins", text: "CORROBORATED" },
  ]);
  assert.equal(changes[0].section, "The bridge");
  assert.ok(changes[2].fields.every((f) => f.diff.every((s) => s.op === "ins")));
  assert.ok(changes[3].fields.every((f) => f.diff.every((s) => s.op === "del")));
  assert.deepEqual(claimChanges(v1(), v1()), []);
});

test("reportChangeSummary: every kind of change, in a fixed order", () => {
  assert.deepEqual(reportChangeSummary(v1(), v2()), [
    "Title changed: “Checking a demo article” → “Checking the demo article”",
    "Series added: “Demo checks”",
    "Subtitle removed (was “Three claims”)",
    "Claim added: k4 “The mail”",
    "Claim removed: k3 “A third claim.”",
    "Verdict changed: k1 PARTLY → CORROBORATED",
    "Claims edited: k1 (text), k2 (findings)",
    "Citation added: c04",
    "Citation removed: c03",
    "Quote edited: c02",
  ]);
});

test("reportChangeSummary: the first revision counts; an edit outside the list says so", () => {
  assert.deepEqual(reportChangeSummary(null, v1()), ["First revision: 1 section, 3 claims, 3 citations."]);
  const moved = v1();
  (moved.citations!.c01 as { start: number }).start = 11;
  assert.deepEqual(reportChangeSummary(v1(), moved), ["Other edits: no title, claim, verdict, citation or quote changed"]);
  const summary = v1();
  summary.summary = "A new summary.";
  assert.deepEqual(reportChangeSummary(v1(), summary), ["Summary edited"]);
});

test("reportChangeSummary: long lists are cut, long labels shortened", () => {
  const many = v1();
  for (let i = 0; i < 15; i++) {
    many.sections[0].claims!.push({ id: `n${i}`, text: `${"x".repeat(100)} ${i}` });
  }
  const [line] = reportChangeSummary(v1(), many);
  assert.match(line, /^15 claims added: n0 “x{79}…”, /);
  assert.match(line, / and 3 more$/);
});

test("the commit message carries the summary, and gives it back", () => {
  const lines = reportChangeSummary(v1(), v2());
  const msg = revisionCommitMessage(2, lines);
  assert.match(msg, /^Revision 2\n\n- Title changed/);
  assert.deepEqual(revisionSummaryOf(msg), lines);
});