package gitcmd

import (
	"testing"
)

func findFile(t *testing.T, d *DiffResult, path string) *FileChange {
	t.Helper()
	for i := range d.Files {
		if d.Files[i].Path == path {
			return &d.Files[i]
		}
	}
	return nil
}

func TestCommitDiff_Modify(t *testing.T) {
	f := newFixture(t)
	d, err := f.repo.CommitDiff(f.c3)
	if err != nil {
		t.Fatal(err)
	}
	if len(d.Files) != 1 {
		t.Fatalf("files = %d, want 1: %+v", len(d.Files), d.Files)
	}
	fc := &d.Files[0]
	if fc.Path != "README.md" || fc.Status != "M" {
		t.Errorf("file = %+v, want README.md/M", fc)
	}
	if fc.Additions != 1 || fc.Deletions != 1 {
		t.Errorf("adds/dels = %d/%d, want 1/1", fc.Additions, fc.Deletions)
	}
	if len(fc.Hunks) != 1 {
		t.Fatalf("hunks = %d, want 1", len(fc.Hunks))
	}
	h := fc.Hunks[0]
	if h.OldStart != 1 || h.OldCount != 2 || h.NewStart != 1 || h.NewCount != 2 {
		t.Errorf("hunk header = -%d,%d +%d,%d, want -1,2 +1,2", h.OldStart, h.OldCount, h.NewStart, h.NewCount)
	}
	wantLines := []DiffLine{
		{DiffLineContext, "line1"},
		{DiffLineDelete, "line2"},
		{DiffLineAdd, "line3"},
	}
	if len(h.Lines) != len(wantLines) {
		t.Fatalf("lines = %d, want %d: %+v", len(h.Lines), len(wantLines), h.Lines)
	}
	for i, wl := range wantLines {
		if h.Lines[i] != wl {
			t.Errorf("line[%d] = %+v, want %+v", i, h.Lines[i], wl)
		}
	}
}

func TestCommitDiff_Add(t *testing.T) {
	f := newFixture(t)
	d, err := f.repo.CommitDiff(f.c2)
	if err != nil {
		t.Fatal(err)
	}
	if len(d.Files) != 2 {
		t.Fatalf("files = %d, want 2", len(d.Files))
	}
	fc := findFile(t, d, "src/main.txt")
	if fc == nil {
		t.Fatal("src/main.txt not in diff")
	}
	if fc.Status != "A" || fc.Additions != 1 || fc.Deletions != 0 {
		t.Errorf("src/main.txt = %+v, want A/1/0", fc)
	}
	if len(fc.Hunks) != 1 {
		t.Fatalf("hunks = %d, want 1", len(fc.Hunks))
	}
	h := fc.Hunks[0]

	if h.OldStart != 0 || h.OldCount != 0 || h.NewStart != 1 || h.NewCount != 1 {
		t.Errorf("hunk header = -%d,%d +%d,%d, want -0,0 +1,1", h.OldStart, h.OldCount, h.NewStart, h.NewCount)
	}
	if len(h.Lines) != 1 || h.Lines[0].Type != DiffLineAdd || h.Lines[0].Text != "main line" {
		t.Errorf("hunk lines = %+v, want [{add 'main line'}]", h.Lines)
	}
}

func TestCommitDiff_Delete(t *testing.T) {
	f := newFixture(t)
	d, err := f.repo.CommitDiff(f.c5)
	if err != nil {
		t.Fatal(err)
	}
	if len(d.Files) != 1 {
		t.Fatalf("files = %d, want 1", len(d.Files))
	}
	fc := &d.Files[0]
	if fc.Path != "deleted.txt" || fc.Status != "D" {
		t.Errorf("file = %+v, want deleted.txt/D", fc)
	}
	if fc.Additions != 0 || fc.Deletions != 1 {
		t.Errorf("adds/dels = %d/%d, want 0/1", fc.Additions, fc.Deletions)
	}
	h := fc.Hunks[0]

	if h.OldStart != 1 || h.OldCount != 1 || h.NewStart != 0 || h.NewCount != 0 {
		t.Errorf("hunk header = -%d,%d +%d,%d, want -1,1 +0,0", h.OldStart, h.OldCount, h.NewStart, h.NewCount)
	}
	if len(h.Lines) != 1 || h.Lines[0].Type != DiffLineDelete || h.Lines[0].Text != "to be deleted" {
		t.Errorf("hunk lines = %+v, want [{delete 'to be deleted'}]", h.Lines)
	}
}

func TestCommitDiff_Binary(t *testing.T) {
	f := newFixture(t)
	d, err := f.repo.CommitDiff(f.c4)
	if err != nil {
		t.Fatal(err)
	}
	if len(d.Files) != 1 {
		t.Fatalf("files = %d, want 1", len(d.Files))
	}
	fc := &d.Files[0]
	if fc.Path != "binary.bin" || fc.Status != "A" || !fc.IsBinary {
		t.Errorf("file = %+v, want binary.bin/A/binary", fc)
	}
	if len(fc.Hunks) != 0 {
		t.Errorf("binary file should have no hunks, got %d", len(fc.Hunks))
	}
}

func TestDiff_TwoTree(t *testing.T) {

	f := newFixture(t)
	d, err := f.repo.Diff(f.c1, f.c5, nil)
	if err != nil {
		t.Fatal(err)
	}
	if len(d.Files) != 3 {
		t.Fatalf("files = %d, want 3: %+v", len(d.Files), d.Files)
	}
	if fc := findFile(t, d, "README.md"); fc == nil || fc.Status != "M" || fc.Additions != 1 || fc.Deletions != 1 {
		t.Errorf("README.md = %+v, want M/1/1", fc)
	}
	if fc := findFile(t, d, "src/main.txt"); fc == nil || fc.Status != "A" || fc.Additions != 1 {
		t.Errorf("src/main.txt = %+v, want A/1", fc)
	}
	if fc := findFile(t, d, "binary.bin"); fc == nil || fc.Status != "A" || !fc.IsBinary {
		t.Errorf("binary.bin = %+v, want A/binary", fc)
	}
}

func TestDiff_PathLimit(t *testing.T) {
	f := newFixture(t)
	d, err := f.repo.Diff(f.c1, f.c5, []string{"README.md"})
	if err != nil {
		t.Fatal(err)
	}
	if len(d.Files) != 1 || d.Files[0].Path != "README.md" {
		t.Fatalf("files = %+v, want only README.md", d.Files)
	}
}