import { assertEquals } from "@std/assert";
import { narrow, parsePatch } from "./patch.ts";

Deno.test("renames, deletions, additions and mode changes read as what happened to each file", () => {
  const files = parsePatch([
    "diff --git a/old.txt b/new.txt",
    "similarity index 79%",
    "rename from old.txt",
    "rename to new.txt",
    "index f384549..b2f931a 100644",
    "--- a/old.txt",
    "+++ b/new.txt",
    "@@ -1,2 +1,3 @@",
    " one",
    " two",
    "+three",
    "diff --git a/keep.txt b/keep.txt",
    "deleted file mode 100644",
    "index de98044..0000000",
    "--- a/keep.txt",
    "+++ /dev/null",
    "@@ -1 +0,0 @@",
    "-a",
    "diff --git a/empty b/empty",
    "new file mode 100644",
    "index 0000000..e69de29",
    "diff --git a/script.sh b/script.sh",
    "old mode 100644",
    "new mode 100755",
    "diff --git a/bin.dat b/bin.dat",
    "index bdc955b..8835708 100644",
    "Binary files a/bin.dat and b/bin.dat differ",
    "",
  ].join("\n"));
  assertEquals(
    files.map(({ path, from, status, modes, binary }) => ({ path, from, status, modes, binary })),
    [
      {
        path: "new.txt",
        from: "old.txt",
        status: "renamed",
        modes: { old: "100644", new: "100644" },
        binary: false,
      },
      {
        path: "keep.txt",
        from: null,
        status: "deleted",
        modes: { old: "100644", new: null },
        binary: false,
      },
      {
        path: "empty",
        from: null,
        status: "added",
        modes: { old: null, new: "100644" },
        binary: false,
      },
      {
        path: "script.sh",
        from: null,
        status: "modified",
        modes: { old: "100644", new: "100755" },
        binary: false,
      },
      {
        path: "bin.dat",
        from: null,
        status: "modified",
        modes: { old: "100644", new: "100644" },
        binary: true,
      },
    ],
  );
  assertEquals(files[0].hunks, [{ old: 1, new: 1, lines: [" one", " two", "+three"] }]);
  assertEquals(files[1].hunks, [{ old: 1, new: 0, lines: ["-a"] }]);
  assertEquals(files[2].hunks, []);
});

Deno.test("hunks keep missing newlines, carriage returns, and lines that look like headers", () => {
  const [file] = parsePatch([
    "commit header that comes first",
    "",
    "diff --git a/x b/x",
    "--- a/x",
    "+++ b/x",
    "@@ -1,3 +1,3 @@",
    "-diff --git a/y b/y",
    "+--- a/y\r",
    "",
    " last",
    "\\ No newline at end of file",
    "",
  ].join("\n"));
  assertEquals(file.hunks, [{
    old: 1,
    new: 1,
    lines: ["-diff --git a/y b/y", "+--- a/y\r", " ", " last", "\\ No newline at end of file"],
  }]);
});

Deno.test("unusual paths read as themselves, quoted or not", () => {
  const files = parsePatch([
    'diff --git a/a.txt "b/b \\"c\\".txt"',
    "similarity index 100%",
    "rename from a.txt",
    'rename to "b \\"c\\".txt"',
    'diff --git "a/we ird\\\\t\\"q\\".txt" "b/we ird\\\\t\\"q\\".txt"',
    "index 45b983b..ab4a981 100644",
    '--- "a/we ird\\\\t\\"q\\".txt"\t',
    '+++ "b/we ird\\\\t\\"q\\".txt"\t',
    "@@ -1 +1 @@",
    "-hi",
    "+ho",
    "diff --git a/ünï cødé.txt b/ünï cødé.txt",
    "new file mode 100644",
    "index 0000000..e69de29",
    'diff --git "a/\\303\\274.txt" "b/\\303\\274.txt"',
    "old mode 100644",
    "new mode 100755",
    "diff --git a/sp ace b/sp ace",
    "--- a/sp ace\t",
    "+++ b/sp ace\t",
    "@@ -1 +1 @@",
    "-a",
    "+b",
  ].join("\n"));
  assertEquals(files.map(({ path, from }) => [path, from]), [
    ['b "c".txt', "a.txt"],
    ['we ird\\t"q".txt', null],
    ["ünï cødé.txt", null],
    ["ü.txt", null],
    ["sp ace", null],
  ]);
});

Deno.test("narrowing a long file keeps the changes and their context, at their own line numbers", () => {
  const lines = Array.from({ length: 30 }, (_, i) => ` ${i + 1}`);
  lines[4] = "-5";
  lines.splice(5, 0, "+five");
  lines[25] = "-25";
  const [file] = parsePatch(
    ["diff --git a/f b/f", "--- a/f", "+++ b/f", "@@ -1,30 +1,30 @@", ...lines].join("\n"),
  );
  assertEquals(narrow(file, 2).hunks, [
    { old: 3, new: 3, lines: [" 3", " 4", "-5", "+five", " 6", " 7"] },
    { old: 23, new: 23, lines: [" 23", " 24", "-25", " 26", " 27"] },
  ]);
});