package installer

import (
	"context"
	"errors"
	"fmt"
	"io"
	"os"
	"os/exec"
	"path/filepath"

	"gitea.loveuer.com/yizhisec/pkg3/logger"
)

type installer struct {
	workdir string
	target  string
}

func (i *installer) buildCommand(ctx context.Context, cmds ...string) *exec.Cmd {
	if len(cmds) == 0 {
		return nil
	}

	if i.target == "self" {
		return exec.CommandContext(ctx, cmds[0], cmds[1:]...)
	}

	sshArgs := append([]string{i.target}, cmds...)
	return exec.CommandContext(ctx, "ssh", sshArgs...)
}

// ExecuteCommand implements syscheck.CommandExecutor interface
func (i *installer) ExecuteCommand(ctx context.Context, cmds ...string) (string, error) {
	cmd := i.buildCommand(ctx, cmds...)
	if cmd == nil {
		return "", fmt.Errorf("failed to build command")
	}

	output, err := cmd.CombinedOutput()
	if err != nil {
		return "", fmt.Errorf("command failed: %w, output: %s", err, string(output))
	}

	return string(output), nil
}

type CopyFileOption func(*copyFileOptions)
type copyFileOptions struct {
	addExecutable bool
}

func withCopyFileExecutable() func(*copyFileOptions) {
	return func(o *copyFileOptions) {
		o.addExecutable = true
	}
}

func (i *installer) copyFile(ctx context.Context, src, dst string, opts ...CopyFileOption) error {
	logger.Debug("☑️ installer.copyFile: Copying file from %s to %s (target: %s)", src, dst, i.target)

	var (
		err              error
		o                = &copyFileOptions{}
		srcFile, dstFile *os.File
		srcInfo          os.FileInfo
	)

	for _, fn := range opts {
		fn(o)
	}

	if i.target == "self" {
		// Simply copy file locally
		logger.Debug("Copying file locally: %s -> %s", src, dst)

		// Open source file
		if srcFile, err = os.Open(src); err != nil {
			logger.Error("❌ Failed to open source file %s: %v", src, err)
			return fmt.Errorf("failed to open source file: %w", err)
		}
		defer srcFile.Close()

		// Create destination directory if needed
		dstDir := filepath.Dir(dst)
		if err = os.MkdirAll(dstDir, 0755); err != nil {
			logger.Error("❌ Failed to create destination directory %s: %v", dstDir, err)
			return fmt.Errorf("failed to create destination directory: %w", err)
		}

		// Create destination file
		if dstFile, err = os.Create(dst); err != nil {
			logger.Error("❌ Failed to create destination file %s: %v", dst, err)
			return fmt.Errorf("failed to create destination file: %w", err)
		}
		defer dstFile.Close()

		// Copy file content
		if _, err = io.Copy(dstFile, srcFile); err != nil {
			logger.Error("❌ Failed to copy file content: %v", err)
			return fmt.Errorf("failed to copy file content: %w", err)
		}

		// Get source file permissions
		if srcInfo, err = os.Stat(src); err == nil {
			if err = os.Chmod(dst, srcInfo.Mode()); err != nil {
				logger.Debug("⚠️ Failed to set file permissions: %v", err)
			}
		}

		logger.Info("✅ File copied locally: %s -> %s", src, dst)
		return nil
	}

	// Copy file via scp to remote target
	logger.Debug("Copying file via scp: %s -> %s:%s", src, i.target, dst)

	// Format: scp <src> <target>:<dst>
	cmd := exec.CommandContext(ctx, "scp", src, fmt.Sprintf("%s:%s", i.target, dst))
	output, err := cmd.CombinedOutput()
	if err != nil {
		logger.Error("❌ Failed to copy file via scp: %v, output: %s", err, string(output))
		return fmt.Errorf("failed to copy file via scp: %w, output: %s", err, string(output))
	}

	logger.Info("✅ File copied via scp: %s -> %s:%s", src, i.target, dst)
	return nil
}

func (i *installer) targetOK(ctx context.Context) error {
	cmd := i.buildCommand(ctx, "whoami")
	output, err := cmd.CombinedOutput()
	if err != nil {
		logger.Debug("❌ installer.targetOK: check target %s failed, err = %v", i.target, err)
		return err
	}

	if string(output) != "root\n" {
		logger.Debug("❌ installer.targetOK: check target %s failed, output = %s", i.target, string(output))
		return errors.New("target is not root user")
	}

	return nil
}

func NewInstaller(workdir, target string) *installer {
	if target == "" {
		logger.Warn("🎯 NewInstaller: target empty, set to default(self)")
		target = "self"
	}

	return &installer{workdir: workdir, target: target}
}