package git

import (
	"errors"
	"fmt"
	"os"
	"os/exec"
	"strconv"
	"strings"

	"github.com/davecgh/go-spew/spew"
	"github.com/gabrie30/ghorg/scm"
)

type Gitter interface {
	Clone(scm.Repo) error
	Reset(scm.Repo) error
	Pull(scm.Repo) error
	SetOrigin(scm.Repo) error
	SetOriginWithCredentials(scm.Repo) error
	Clean(scm.Repo) error
	Checkout(scm.Repo) error
	RevListCompare(scm.Repo, string, string) (string, error)
	ShortStatus(scm.Repo) (string, error)
	Branch(scm.Repo) (string, error)
	UpdateRemote(scm.Repo) error
	FetchAll(scm.Repo) error
	FetchCloneBranch(scm.Repo) error
	RepoCommitCount(scm.Repo) (int, error)
	HasRemoteHeads(scm.Repo) (bool, error)
}

type GitClient struct{}

func NewGit() GitClient {
	return GitClient{}
}

func printDebugCmd(cmd *exec.Cmd, repo scm.Repo) error {
	fmt.Println("------------- GIT DEBUG -------------")
	fmt.Printf("GHORG_OUTPUT_DIR=%v\n", os.Getenv("GHORG_OUTPUT_DIR"))
	fmt.Printf("GHORG_ABSOLUTE_PATH_TO_CLONE_TO=%v\n", os.Getenv("GHORG_ABSOLUTE_PATH_TO_CLONE_TO"))
	fmt.Print("Repo Data: ")
	spew.Dump(repo)
	fmt.Print("Command Ran: ")
	spew.Dump(*cmd)
	fmt.Println("")
	output, err := cmd.CombinedOutput()
	fmt.Printf("Command Output: %s\n", string(output))
	if err != nil {
		fmt.Printf("Error: %v\n", err)
	}
	return err
}

func (g GitClient) HasRemoteHeads(repo scm.Repo) (bool, error) {
	cmd := exec.Command("git", "ls-remote", "--heads", "--quiet", "--exit-code")

	err := cmd.Run()
	if err == nil {
		// successfully listed the remote heads
		return true, nil
	}

	var exitError *exec.ExitError
	if !errors.As(err, &exitError) {
		// error, but no exit code, return err
		return false, err
	}

	exitCode := exitError.ExitCode()
	if exitCode == 0 {
		// ls-remote did successfully list the remote heads
		return true, nil
	} else if exitCode == 2 {
		// repository is empty
		return false, nil
	} else {
		// another exit code, simply return err
		return false, err
	}

}

func (g GitClient) Clone(repo scm.Repo) error {
	args := []string{"clone", repo.CloneURL, repo.HostPath}

	if os.Getenv("GHORG_INCLUDE_SUBMODULES") == "true" {
		index := 1
		args = append(args[:index+1], args[index:]...)
		args[index] = "--recursive"
	}

	if os.Getenv("GHORG_CLONE_DEPTH") != "" {
		index := 1
		args = append(args[:index+1], args[index:]...)
		args[index] = fmt.Sprintf("--depth=%v", os.Getenv("GHORG_CLONE_DEPTH"))
	}

	if os.Getenv("GHORG_GIT_FILTER") != "" {
		index := 1
		args = append(args[:index+1], args[index:]...)
		args[index] = fmt.Sprintf("--filter=%v", os.Getenv("GHORG_GIT_FILTER"))
	}

	if os.Getenv("GHORG_BACKUP") == "true" {
		args = append(args, "--mirror")
	}

	cmd := exec.Command("git", args...)

	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}

	err := cmd.Run()
	return err
}

func (g GitClient) SetOriginWithCredentials(repo scm.Repo) error {
	args := []string{"remote", "set-url", "origin", repo.CloneURL}
	cmd := exec.Command("git", args...)
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}
	return cmd.Run()
}

func (g GitClient) SetOrigin(repo scm.Repo) error {
	args := []string{"remote", "set-url", "origin", repo.URL}
	cmd := exec.Command("git", args...)
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}
	return cmd.Run()
}

func (g GitClient) Checkout(repo scm.Repo) error {
	cmd := exec.Command("git", "checkout", repo.CloneBranch)
	cmd.Dir = repo.HostPath

	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}

	return cmd.Run()
}

func (g GitClient) Clean(repo scm.Repo) error {
	cmd := exec.Command("git", "clean", "-f", "-d")
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}
	return cmd.Run()
}

func (g GitClient) UpdateRemote(repo scm.Repo) error {
	cmd := exec.Command("git", "remote", "update")
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}
	return cmd.Run()
}

func (g GitClient) Pull(repo scm.Repo) error {
	args := []string{"pull", "origin", repo.CloneBranch}

	if os.Getenv("GHORG_INCLUDE_SUBMODULES") == "true" {
		index := 1
		args = append(args[:index+1], args[index:]...)
		args[index] = "--recurse-submodules"
	}

	if os.Getenv("GHORG_CLONE_DEPTH") != "" {
		index := 1
		args = append(args[:index+1], args[index:]...)
		args[index] = fmt.Sprintf("--depth=%v", os.Getenv("GHORG_CLONE_DEPTH"))
	}

	cmd := exec.Command("git", args...)
	cmd.Dir = repo.HostPath

	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}

	return cmd.Run()
}

func (g GitClient) Reset(repo scm.Repo) error {
	cmd := exec.Command("git", "reset", "--hard", "origin/"+repo.CloneBranch)
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}
	return cmd.Run()
}

func (g GitClient) FetchAll(repo scm.Repo) error {
	args := []string{"fetch", "--all"}

	if os.Getenv("GHORG_CLONE_DEPTH") != "" {
		index := 1
		args = append(args[:index+1], args[index:]...)
		args[index] = fmt.Sprintf("--depth=%v", os.Getenv("GHORG_CLONE_DEPTH"))
	}
	cmd := exec.Command("git", args...)
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}
	return cmd.Run()
}

func (g GitClient) Branch(repo scm.Repo) (string, error) {
	args := []string{"branch"}

	cmd := exec.Command("git", args...)
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		if err := printDebugCmd(cmd, repo); err != nil {
			return "", err
		}
	}

	output, err := cmd.Output()
	if err != nil {
		return "", err
	}

	return strings.TrimSpace(string(output)), nil
}

// RevListCompare returns the list of commits in the local branch that are not in the remote branch.
func (g GitClient) RevListCompare(repo scm.Repo, localBranch string, remoteBranch string) (string, error) {
	cmd := exec.Command("git", "-C", repo.HostPath, "rev-list", localBranch, "^"+remoteBranch)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return "", err
	}
	return strings.TrimSpace(string(output)), nil
}

func (g GitClient) FetchCloneBranch(repo scm.Repo) error {
	args := []string{"fetch", "origin", repo.CloneBranch}

	if os.Getenv("GHORG_CLONE_DEPTH") != "" {
		index := 1
		args = append(args[:index+1], args[index:]...)
		args[index] = fmt.Sprintf("--depth=%v", os.Getenv("GHORG_CLONE_DEPTH"))
	}
	cmd := exec.Command("git", args...)
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		return printDebugCmd(cmd, repo)
	}
	return cmd.Run()
}

func (g GitClient) ShortStatus(repo scm.Repo) (string, error) {
	args := []string{"status", "--short"}

	cmd := exec.Command("git", args...)
	cmd.Dir = repo.HostPath
	if os.Getenv("GHORG_DEBUG") != "" {
		if err := printDebugCmd(cmd, repo); err != nil {
			return "", err
		}
	}

	output, err := cmd.Output()
	if err != nil {
		return "", err
	}

	return strings.TrimSpace(string(output)), nil
}

func (g GitClient) RepoCommitCount(repo scm.Repo) (int, error) {
	args := []string{"rev-list", "--count", repo.CloneBranch, "--"}
	cmd := exec.Command("git", args...)
	cmd.Dir = repo.HostPath

	if os.Getenv("GHORG_DEBUG") != "" {
		err := printDebugCmd(cmd, repo)
		if err != nil {
			return 0, err
		}
	}

	output, err := cmd.Output()
	if err != nil {
		return 0, err
	}

	count, err := strconv.Atoi(strings.TrimSpace(string(output)))
	if err != nil {
		return 0, err
	}

	return count, nil
}