package git

import (
	"os"
	"path/filepath"
	"testing"

	"git.membo.co.uk/dtomlinson/gitlocal/internal/testutil"
)

func TestIsGitRepo(t *testing.T) {
	tests := []struct {
		name     string
		setup    func(t *testing.T) string
		expected bool
	}{
		{
			name: "valid git repo",
			setup: func(t *testing.T) string {
				return testutil.CreateTempGitRepo(t)
			},
			expected: true,
		},
		{
			name: "not a git repo",
			setup: func(t *testing.T) string {
				return t.TempDir()
			},
			expected: false,
		},
		{
			name: "has .gitlocal but not .git",
			setup: func(t *testing.T) string {
				dir := t.TempDir()
				gitLocalDir := filepath.Join(dir, GitLocalDir)
				if err := os.Mkdir(gitLocalDir, 0755); err != nil {
					t.Fatalf("failed to create .gitlocal: %v", err)
				}
				return dir
			},
			expected: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			path := tt.setup(t)
			result := IsGitRepo(path)
			if result != tt.expected {
				t.Errorf("expected %v, got %v", tt.expected, result)
			}
		})
	}
}

func TestIsGitLocalRepo(t *testing.T) {
	tests := []struct {
		name     string
		setup    func(t *testing.T) string
		expected bool
	}{
		{
			name: "has .gitlocal",
			setup: func(t *testing.T) string {
				dir := t.TempDir()
				gitLocalDir := filepath.Join(dir, GitLocalDir)
				if err := os.Mkdir(gitLocalDir, 0755); err != nil {
					t.Fatalf("failed to create .gitlocal: %v", err)
				}
				return dir
			},
			expected: true,
		},
		{
			name: "has .git but not .gitlocal",
			setup: func(t *testing.T) string {
				return testutil.CreateTempGitRepo(t)
			},
			expected: false,
		},
		{
			name: "has neither",
			setup: func(t *testing.T) string {
				return t.TempDir()
			},
			expected: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			path := tt.setup(t)
			result := IsGitLocalRepo(path)
			if result != tt.expected {
				t.Errorf("expected %v, got %v", tt.expected, result)
			}
		})
	}
}

func TestGetRemoteURL(t *testing.T) {
	tests := []struct {
		name     string
		setup    func(t *testing.T) string
		expected string
	}{
		{
			name: "repo with remote",
			setup: func(t *testing.T) string {
				dir := testutil.CreateTempGitRepoWithRemote(t, "git@github.com:test/repo.git")
				return filepath.Join(dir, GitDir)
			},
			expected: "git@github.com:test/repo.git",
		},
		{
			name: "repo without remote",
			setup: func(t *testing.T) string {
				dir := testutil.CreateTempGitRepo(t)
				return filepath.Join(dir, GitDir)
			},
			expected: "",
		},
		{
			name: "invalid git dir",
			setup: func(t *testing.T) string {
				return "/nonexistent/.git"
			},
			expected: "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			gitDir := tt.setup(t)
			result := GetRemoteURL(gitDir)
			if result != tt.expected {
				t.Errorf("expected %q, got %q", tt.expected, result)
			}
		})
	}
}

func TestGetCurrentBranch(t *testing.T) {
	tests := []struct {
		name     string
		setup    func(t *testing.T) string
		expected string
	}{
		{
			name: "default branch (master or main)",
			setup: func(t *testing.T) string {
				dir := testutil.CreateTempGitRepo(t)
				return filepath.Join(dir, GitDir)
			},
			// Git might use master or main depending on config
			expected: "", // We'll check it's non-empty instead
		},
		{
			name: "custom branch",
			setup: func(t *testing.T) string {
				dir := testutil.CreateTempGitRepoWithBranch(t, "develop")
				return filepath.Join(dir, GitDir)
			},
			expected: "develop",
		},
		{
			name: "invalid git dir",
			setup: func(t *testing.T) string {
				return "/nonexistent/.git"
			},
			expected: "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			gitDir := tt.setup(t)
			result := GetCurrentBranch(gitDir)

			if tt.name == "default branch (master or main)" {
				// Just check it returned something
				if result == "" {
					t.Errorf("expected non-empty branch name, got empty string")
				}
			} else if result != tt.expected {
				t.Errorf("expected %q, got %q", tt.expected, result)
			}
		})
	}
}

func TestConvert(t *testing.T) {
	tests := []struct {
		name      string
		setup     func(t *testing.T) string
		expectErr bool
	}{
		{
			name: "valid git repo",
			setup: func(t *testing.T) string {
				return testutil.CreateTempGitRepo(t)
			},
			expectErr: false,
		},
		{
			name: "no .git directory",
			setup: func(t *testing.T) string {
				return t.TempDir()
			},
			expectErr: true,
		},
		{
			name: ".gitlocal already exists",
			setup: func(t *testing.T) string {
				dir := testutil.CreateTempGitRepo(t)
				gitLocalDir := filepath.Join(dir, GitLocalDir)
				if err := os.Mkdir(gitLocalDir, 0755); err != nil {
					t.Fatalf("failed to create .gitlocal: %v", err)
				}
				return dir
			},
			expectErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			path := tt.setup(t)
			err := Convert(path)

			if tt.expectErr && err == nil {
				t.Errorf("expected error, got nil")
			}

			if !tt.expectErr && err != nil {
				t.Errorf("expected no error, got %v", err)
			}

			if !tt.expectErr {
				// Verify .git was renamed to .gitlocal
				gitPath := filepath.Join(path, GitDir)
				gitLocalPath := filepath.Join(path, GitLocalDir)

				if _, err := os.Stat(gitPath); !os.IsNotExist(err) {
					t.Errorf(".git directory still exists")
				}

				if _, err := os.Stat(gitLocalPath); os.IsNotExist(err) {
					t.Errorf(".gitlocal directory does not exist")
				}
			}
		})
	}
}

func TestRevert(t *testing.T) {
	tests := []struct {
		name      string
		setup     func(t *testing.T) string
		expectErr bool
	}{
		{
			name: "valid .gitlocal directory",
			setup: func(t *testing.T) string {
				dir := testutil.CreateTempGitRepo(t)
				// Convert to .gitlocal
				if err := Convert(dir); err != nil {
					t.Fatalf("failed to convert: %v", err)
				}
				return dir
			},
			expectErr: false,
		},
		{
			name: "no .gitlocal directory",
			setup: func(t *testing.T) string {
				return t.TempDir()
			},
			expectErr: true,
		},
		{
			name: ".git already exists",
			setup: func(t *testing.T) string {
				dir := testutil.CreateTempGitRepo(t)
				gitLocalDir := filepath.Join(dir, GitLocalDir)
				if err := os.Mkdir(gitLocalDir, 0755); err != nil {
					t.Fatalf("failed to create .gitlocal: %v", err)
				}
				return dir
			},
			expectErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			path := tt.setup(t)
			err := Revert(path)

			if tt.expectErr && err == nil {
				t.Errorf("expected error, got nil")
			}

			if !tt.expectErr && err != nil {
				t.Errorf("expected no error, got %v", err)
			}

			if !tt.expectErr {
				// Verify .gitlocal was renamed to .git
				gitPath := filepath.Join(path, GitDir)
				gitLocalPath := filepath.Join(path, GitLocalDir)

				if _, err := os.Stat(gitLocalPath); !os.IsNotExist(err) {
					t.Errorf(".gitlocal directory still exists")
				}

				if _, err := os.Stat(gitPath); os.IsNotExist(err) {
					t.Errorf(".git directory does not exist")
				}
			}
		})
	}
}

func TestConvertRevertRoundTrip(t *testing.T) {
	dir := testutil.CreateTempGitRepoWithRemote(t, "git@github.com:test/repo.git")

	// Initial state - should have .git
	if !IsGitRepo(dir) {
		t.Fatal("expected .git to exist initially")
	}

	// Convert
	if err := Convert(dir); err != nil {
		t.Fatalf("convert failed: %v", err)
	}

	// Should have .gitlocal, not .git
	if IsGitRepo(dir) {
		t.Error("expected .git to be gone after convert")
	}
	if !IsGitLocalRepo(dir) {
		t.Error("expected .gitlocal to exist after convert")
	}

	// Remote should still be accessible via .gitlocal
	gitLocalPath := filepath.Join(dir, GitLocalDir)
	remote := GetRemoteURL(gitLocalPath)
	if remote != "git@github.com:test/repo.git" {
		t.Errorf("expected remote to be preserved, got %q", remote)
	}

	// Revert
	if err := Revert(dir); err != nil {
		t.Fatalf("revert failed: %v", err)
	}

	// Should have .git again, not .gitlocal
	if !IsGitRepo(dir) {
		t.Error("expected .git to exist after revert")
	}
	if IsGitLocalRepo(dir) {
		t.Error("expected .gitlocal to be gone after revert")
	}

	// Remote should still be accessible
	gitPath := filepath.Join(dir, GitDir)
	remote = GetRemoteURL(gitPath)
	if remote != "git@github.com:test/repo.git" {
		t.Errorf("expected remote to be preserved after round trip, got %q", remote)
	}
}