package commands

import (
	"fmt"
	"os/exec"
	"runtime"
	"testing"

	"github.com/jesseduffield/lazygit/pkg/commands/models"
	"github.com/jesseduffield/lazygit/pkg/secureexec"
	"github.com/jesseduffield/lazygit/pkg/test"
	"github.com/stretchr/testify/assert"
)

// TestGitCommandCatFile tests emitting a file using commands, where commands vary by OS.
func TestGitCommandCatFile(t *testing.T) {
	var osCmd string
	switch os := runtime.GOOS; os {
	case "windows":
		osCmd = "type"
	default:
		osCmd = "cat"
	}
	gitCmd := NewDummyGitCommand()
	gitCmd.OSCommand.Command = func(cmd string, args ...string) *exec.Cmd {
		assert.EqualValues(t, osCmd, cmd)
		assert.EqualValues(t, []string{"test.txt"}, args)

		return secureexec.Command("echo", "-n", "test")
	}

	o, err := gitCmd.CatFile("test.txt")
	assert.NoError(t, err)
	assert.Equal(t, "test", o)
}

// TestGitCommandStageFile is a function.
func TestGitCommandStageFile(t *testing.T) {
	gitCmd := NewDummyGitCommand()
	gitCmd.OSCommand.Command = func(cmd string, args ...string) *exec.Cmd {
		assert.EqualValues(t, "git", cmd)
		assert.EqualValues(t, []string{"add", "--", "test.txt"}, args)

		return secureexec.Command("echo")
	}

	assert.NoError(t, gitCmd.StageFile("test.txt"))
}

// TestGitCommandUnstageFile is a function.
func TestGitCommandUnstageFile(t *testing.T) {
	type scenario struct {
		testName string
		command  func(string, ...string) *exec.Cmd
		test     func(error)
		reset    bool
	}

	scenarios := []scenario{
		{
			"Remove an untracked file from staging",
			func(cmd string, args ...string) *exec.Cmd {
				assert.EqualValues(t, "git", cmd)
				assert.EqualValues(t, []string{"rm", "--cached", "--force", "--", "test.txt"}, args)

				return secureexec.Command("echo")
			},
			func(err error) {
				assert.NoError(t, err)
			},
			false,
		},
		{
			"Remove a tracked file from staging",
			func(cmd string, args ...string) *exec.Cmd {
				assert.EqualValues(t, "git", cmd)
				assert.EqualValues(t, []string{"reset", "HEAD", "--", "test.txt"}, args)

				return secureexec.Command("echo")
			},
			func(err error) {
				assert.NoError(t, err)
			},
			true,
		},
	}

	for _, s := range scenarios {
		t.Run(s.testName, func(t *testing.T) {
			gitCmd := NewDummyGitCommand()
			gitCmd.OSCommand.Command = s.command
			s.test(gitCmd.UnStageFile([]string{"test.txt"}, s.reset))
		})
	}
}

// TestGitCommandDiscardAllFileChanges is a function.
// these tests don't cover everything, in part because we already have an integration
// test which does cover everything. I don't want to unnecessarily assert on the 'how'
// when the 'what' is what matters
func TestGitCommandDiscardAllFileChanges(t *testing.T) {
	type scenario struct {
		testName   string
		command    func() (func(string, ...string) *exec.Cmd, *[][]string)
		test       func(*[][]string, error)
		file       *models.File
		removeFile func(string) error
	}

	scenarios := []scenario{
		{
			"An error occurred when resetting",
			func() (func(string, ...string) *exec.Cmd, *[][]string) {
				cmdsCalled := [][]string{}
				return func(cmd string, args ...string) *exec.Cmd {
					cmdsCalled = append(cmdsCalled, args)

					return secureexec.Command("test")
				}, &cmdsCalled
			},
			func(cmdsCalled *[][]string, err error) {
				assert.Error(t, err)
				assert.Len(t, *cmdsCalled, 1)
				assert.EqualValues(t, *cmdsCalled, [][]string{
					{"reset", "--", "test"},
				})
			},
			&models.File{
				Name:             "test",
				HasStagedChanges: true,
			},
			func(string) error {
				return nil
			},
		},
		{
			"An error occurred when removing file",
			func() (func(string, ...string) *exec.Cmd, *[][]string) {
				cmdsCalled := [][]string{}
				return func(cmd string, args ...string) *exec.Cmd {
					cmdsCalled = append(cmdsCalled, args)

					return secureexec.Command("test")
				}, &cmdsCalled
			},
			func(cmdsCalled *[][]string, err error) {
				assert.Error(t, err)
				assert.EqualError(t, err, "an error occurred when removing file")
				assert.Len(t, *cmdsCalled, 0)
			},
			&models.File{
				Name:    "test",
				Tracked: false,
				Added:   true,
			},
			func(string) error {
				return fmt.Errorf("an error occurred when removing file")
			},
		},
		{
			"An error occurred with checkout",
			func() (func(string, ...string) *exec.Cmd, *[][]string) {
				cmdsCalled := [][]string{}
				return func(cmd string, args ...string) *exec.Cmd {
					cmdsCalled = append(cmdsCalled, args)

					return secureexec.Command("test")
				}, &cmdsCalled
			},
			func(cmdsCalled *[][]string, err error) {
				assert.Error(t, err)
				assert.Len(t, *cmdsCalled, 1)
				assert.EqualValues(t, *cmdsCalled, [][]string{
					{"checkout", "--", "test"},
				})
			},
			&models.File{
				Name:             "test",
				Tracked:          true,
				HasStagedChanges: false,
			},
			func(string) error {
				return nil
			},
		},
		{
			"Checkout only",
			func() (func(string, ...string) *exec.Cmd, *[][]string) {
				cmdsCalled := [][]string{}
				return func(cmd string, args ...string) *exec.Cmd {
					cmdsCalled = append(cmdsCalled, args)

					return secureexec.Command("echo")
				}, &cmdsCalled
			},
			func(cmdsCalled *[][]string, err error) {
				assert.NoError(t, err)
				assert.Len(t, *cmdsCalled, 1)
				assert.EqualValues(t, *cmdsCalled, [][]string{
					{"checkout", "--", "test"},
				})
			},
			&models.File{
				Name:             "test",
				Tracked:          true,
				HasStagedChanges: false,
			},
			func(string) error {
				return nil
			},
		},
		{
			"Reset and checkout staged changes",
			func() (func(string, ...string) *exec.Cmd, *[][]string) {
				cmdsCalled := [][]string{}
				return func(cmd string, args ...string) *exec.Cmd {
					cmdsCalled = append(cmdsCalled, args)

					return secureexec.Command("echo")
				}, &cmdsCalled
			},
			func(cmdsCalled *[][]string, err error) {
				assert.NoError(t, err)
				assert.Len(t, *cmdsCalled, 2)
				assert.EqualValues(t, *cmdsCalled, [][]string{
					{"reset", "--", "test"},
					{"checkout", "--", "test"},
				})
			},
			&models.File{
				Name:             "test",
				Tracked:          true,
				HasStagedChanges: true,
			},
			func(string) error {
				return nil
			},
		},
		{
			"Reset and checkout merge conflicts",
			func() (func(string, ...string) *exec.Cmd, *[][]string) {
				cmdsCalled := [][]string{}
				return func(cmd string, args ...string) *exec.Cmd {
					cmdsCalled = append(cmdsCalled, args)

					return secureexec.Command("echo")
				}, &cmdsCalled
			},
			func(cmdsCalled *[][]string, err error) {
				assert.NoError(t, err)
				assert.Len(t, *cmdsCalled, 2)
				assert.EqualValues(t, *cmdsCalled, [][]string{
					{"reset", "--", "test"},
					{"checkout", "--", "test"},
				})
			},
			&models.File{
				Name:              "test",
				Tracked:           true,
				HasMergeConflicts: true,
			},
			func(string) error {
				return nil
			},
		},
		{
			"Reset and remove",
			func() (func(string, ...string) *exec.Cmd, *[][]string) {
				cmdsCalled := [][]string{}
				return func(cmd string, args ...string) *exec.Cmd {
					cmdsCalled = append(cmdsCalled, args)

					return secureexec.Command("echo")
				}, &cmdsCalled
			},
			func(cmdsCalled *[][]string, err error) {
				assert.NoError(t, err)
				assert.Len(t, *cmdsCalled, 1)
				assert.EqualValues(t, *cmdsCalled, [][]string{
					{"reset", "--", "test"},
				})
			},
			&models.File{
				Name:             "test",
				Tracked:          false,
				Added:            true,
				HasStagedChanges: true,
			},
			func(filename string) error {
				assert.Equal(t, "test", filename)
				return nil
			},
		},
		{
			"Remove only",
			func() (func(string, ...string) *exec.Cmd, *[][]string) {
				cmdsCalled := [][]string{}
				return func(cmd string, args ...string) *exec.Cmd {
					cmdsCalled = append(cmdsCalled, args)

					return secureexec.Command("echo")
				}, &cmdsCalled
			},
			func(cmdsCalled *[][]string, err error) {
				assert.NoError(t, err)
				assert.Len(t, *cmdsCalled, 0)
			},
			&models.File{
				Name:             "test",
				Tracked:          false,
				Added:            true,
				HasStagedChanges: false,
			},
			func(filename string) error {
				assert.Equal(t, "test", filename)
				return nil
			},
		},
	}

	for _, s := range scenarios {
		t.Run(s.testName, func(t *testing.T) {
			var cmdsCalled *[][]string
			gitCmd := NewDummyGitCommand()
			gitCmd.OSCommand.Command, cmdsCalled = s.command()
			gitCmd.removeFile = s.removeFile
			s.test(cmdsCalled, gitCmd.DiscardAllFileChanges(s.file))
		})
	}
}

// TestGitCommandDiff is a function.
func TestGitCommandDiff(t *testing.T) {
	type scenario struct {
		testName string
		command  func(string, ...string) *exec.Cmd
		file     *models.File
		plain    bool
		cached   bool
	}

	scenarios := []scenario{
		{
			"Default case",
			func(cmd string, args ...string) *exec.Cmd {
				assert.EqualValues(t, "git", cmd)
				assert.EqualValues(t, []string{"diff", "--submodule", "--no-ext-diff", "--color=always", "--", "test.txt"}, args)

				return secureexec.Command("echo")
			},
			&models.File{
				Name:             "test.txt",
				HasStagedChanges: false,
				Tracked:          true,
			},
			false,
			false,
		},
		{
			"cached",
			func(cmd string, args ...string) *exec.Cmd {
				assert.EqualValues(t, "git", cmd)
				assert.EqualValues(t, []string{"diff", "--submodule", "--no-ext-diff", "--color=always", "--cached", "--", "test.txt"}, args)

				return secureexec.Command("echo")
			},
			&models.File{
				Name:             "test.txt",
				HasStagedChanges: false,
				Tracked:          true,
			},
			false,
			true,
		},
		{
			"plain",
			func(cmd string, args ...string) *exec.Cmd {
				assert.EqualValues(t, "git", cmd)
				assert.EqualValues(t, []string{"diff", "--submodule", "--no-ext-diff", "--color=never", "--", "test.txt"}, args)

				return secureexec.Command("echo")
			},
			&models.File{
				Name:             "test.txt",
				HasStagedChanges: false,
				Tracked:          true,
			},
			true,
			false,
		},
		{
			"File not tracked and file has no staged changes",
			func(cmd string, args ...string) *exec.Cmd {
				assert.EqualValues(t, "git", cmd)
				assert.EqualValues(t, []string{"diff", "--submodule", "--no-ext-diff", "--color=always", "--no-index", "--", "/dev/null", "test.txt"}, args)

				return secureexec.Command("echo")
			},
			&models.File{
				Name:             "test.txt",
				HasStagedChanges: false,
				Tracked:          false,
			},
			false,
			false,
		},
	}

	for _, s := range scenarios {
		t.Run(s.testName, func(t *testing.T) {
			gitCmd := NewDummyGitCommand()
			gitCmd.OSCommand.Command = s.command
			gitCmd.WorktreeFileDiff(s.file, s.plain, s.cached)
		})
	}
}

// TestGitCommandCheckoutFile is a function.
func TestGitCommandCheckoutFile(t *testing.T) {
	type scenario struct {
		testName  string
		commitSha string
		fileName  string
		command   func(string, ...string) *exec.Cmd
		test      func(error)
	}

	scenarios := []scenario{
		{
			"typical case",
			"11af912",
			"test999.txt",
			test.CreateMockCommand(t, []*test.CommandSwapper{
				{
					Expect:  "git checkout 11af912 test999.txt",
					Replace: "echo",
				},
			}),
			func(err error) {
				assert.NoError(t, err)
			},
		},
		{
			"returns error if there is one",
			"11af912",
			"test999.txt",
			test.CreateMockCommand(t, []*test.CommandSwapper{
				{
					Expect:  "git checkout 11af912 test999.txt",
					Replace: "test",
				},
			}),
			func(err error) {
				assert.Error(t, err)
			},
		},
	}

	gitCmd := NewDummyGitCommand()

	for _, s := range scenarios {
		t.Run(s.testName, func(t *testing.T) {
			gitCmd.OSCommand.Command = s.command
			s.test(gitCmd.CheckoutFile(s.commitSha, s.fileName))
		})
	}
}