package packagemanager

import (
	"fmt"
	"log"
	"os"
	"strings"
	"system_setup_tool/internal/shell"
)

type OSManager struct {
	OS           *OS
	SudoPassword string
}

func NewOSManager(sudoPassword string) *OSManager {
	os, err := GetLinuxDistribution()
	if err != nil {
		log.Fatalf("error geting os information: %v", err)
	}
	return &OSManager{
		OS:           os,
		SudoPassword: sudoPassword,
	}
}

func (o *OSManager) Name() string {
	return "OS Package Manager"
}

func (o *OSManager) InstallManager() error { return nil }

func (o *OSManager) Install(packages []string) error {
	if len(packages) == 0 {
		return nil
	}
	err := InstallWithProgress(o, packages)
	if err != nil {
		return err
	}
	return nil
}

func (o *OSManager) InstallPackage(pkg string) error {
	return InstallPackage(o.OS.InstallCommand, pkg, o.SudoPassword)
}

func (o *OSManager) InstallBuildEssentials() error {
	return InstallBuildEssentials(o.OS, o.SudoPassword)
}

func (o *OSManager) RemovePackage(pkg string) error {
	fullCmd := fmt.Sprintf("%s %s", o.OS.RemoveCommand, pkg)
	command := shell.ExecCommand("sudo", "-S", "sh", "-c", fullCmd)
	command.Stdin = strings.NewReader(o.SudoPassword + "\n")
	return command.Run()
}

func (o *OSManager) SearchPackage(pkg string) []string {
	cmdParts := strings.Fields(o.OS.SearchCommand)
	if len(cmdParts) == 0 {
		log.Printf("Invalid search command for OS package manager")
		return []string{}
	}

	cmd := shell.ExecCommand(cmdParts[0], append(cmdParts[1:], pkg)...)
	packages, err := cmd.Output()
	if err != nil {
		log.Printf("Error fetching %s packages: %v", o.OS.PackageManager, err)
		return []string{}
	}

	packageList := strings.Split(strings.TrimSpace(string(packages)), "\n")
	return packageList
}

func (o *OSManager) UpdatePackage(pkg string) error {
	fullCmd := fmt.Sprintf("%s %s", o.OS.UpdateCommand, pkg)
	command := shell.ExecCommand("sudo", "-S", "sh", "-c", fullCmd)
	command.Stdin = strings.NewReader(o.SudoPassword + "\n")
	return command.Run()
}

func (o *OSManager) UpdateAllPackages() error {
	fullCmd := fmt.Sprintf("%s", o.OS.UpdateCommand)
	command := shell.ExecCommand("sudo", "-S", "sh", "-c", fullCmd)
	command.Stdin = strings.NewReader(o.SudoPassword + "\n")
	return command.Run()
}

type OS struct {
	ID             string
	Name           string
	Version        string
	PackageManager string
	InstallCommand string
	SearchCommand  string
	RemoveCommand  string
	UpdateCommand  string
}

func parseOsRelease(osRelease string) *OS {
	var result OS
	result.ID = "Unknown"
	result.Name = "Unknown"
	result.Version = "Unknown"
	result.PackageManager = "Unkown"
	result.InstallCommand = "Unkown"
	result.SearchCommand = "Unkown"
	result.RemoveCommand = "Unkown"
	result.UpdateCommand = "Unkown"

	lines := strings.Split(osRelease, "\n")

	for _, line := range lines {
		splitLine := strings.SplitN(line, "=", 2)
		if len(splitLine) != 2 {
			continue
		}
		switch splitLine[0] {
		case "ID":
			result.ID = strings.ToLower(strings.Trim(splitLine[1], "\""))
		case "NAME":
			result.Name = strings.Trim(splitLine[1], "\"")
		case "VERSION_ID":
			result.Version = strings.Trim(splitLine[1], "\"")
		}
	}
	err := result.getPackageManager()
	if err != nil {
		log.Fatal(err)
	}
	err = result.getInstallCommand()
	if err != nil {
		log.Fatal(err)
	}
	err = result.getSearchCommand()
	if err != nil {
		log.Fatal(err)
	}
	err = result.getUpdateCommand()
	if err != nil {
		log.Fatal(err)
	}
	return &result
}

func GetLinuxDistribution() (*OS, error) {
	_, err := os.Stat("/etc/os-release")
	if os.IsNotExist(err) {
		return nil, fmt.Errorf("unable to read system information")
	}

	osRelease, _ := os.ReadFile("/etc/os-release")
	return parseOsRelease(string(osRelease)), nil
}

func (os *OS) getPackageManager() error {
	switch os.ID {
	case "debian", "ubuntu":
		os.PackageManager = "apt"
		return nil
	case "arch":
		os.PackageManager = "pacman"
		return nil
	case "fedora":
		os.PackageManager = "dnf"
		return nil
	default:
		pmcommands := []string{
			"apt",
			"dnf",
			"pacman",
		}
		for _, pmname := range pmcommands {
			_, err := shell.ExecLookPath(pmname)
			if err == nil {
				os.PackageManager = pmname
				return nil
			}
		}
		return fmt.Errorf("no packagemanager found for os: %s", os)
	}
}

func (os *OS) getInstallCommand() error {
	switch os.PackageManager {
	case "apt":
		os.InstallCommand = "apt install -y"
		return nil
	case "pacman":
		os.InstallCommand = "pacman -S --noconfirm --needed"
		return nil
	case "dnf":
		os.InstallCommand = "dnf install -y --best"
		return nil
	default:
		return fmt.Errorf("no install command found for package manager: %s", os.ID)
	}
}

func (os *OS) getSearchCommand() error {
	switch os.PackageManager {
	case "apt":
		os.SearchCommand = "apt search"
		return nil
	case "pacman":
		os.SearchCommand = "pacman -Ss"
		return nil
	case "dnf":
		os.SearchCommand = "dnf search"
		return nil
	default:
		return fmt.Errorf("no install command found for package manager: %s", os.ID)
	}
}

func (os *OS) getDeleteCommand() error {
	switch os.PackageManager {
	case "apt":
		os.RemoveCommand = "apt remove"
		return nil
	case "pacman":
		os.RemoveCommand = "pacman -R"
		return nil
	case "dnf":
		os.RemoveCommand = "dnf remove"
		return nil
	default:
		return fmt.Errorf("no install command found for package manager: %s", os.ID)
	}
}

func (os *OS) getUpdateCommand() error {
	switch os.PackageManager {
	case "apt":
		os.UpdateCommand = "apt update"
		return nil
	case "pacman":
		os.UpdateCommand = "pacman -S"
		return nil
	case "dnf":
		os.UpdateCommand = "dnf update"
		return nil
	default:
		return fmt.Errorf("no install command found for package manager: %s", os.ID)
	}
}

func InstallBuildEssentials(os *OS, sudoPassword string) error {
	var command string
	switch os.PackageManager {
	case "pacman":
		command = "pacman -S --noconfirm --needed base-devel"
	case "apt":
		command = "apt install -y build-essential"
	case "dnf":
		command = "dnf install -y @development-tools"
	default:
		return fmt.Errorf("keine Build Essentials für OS %s definiert", os.ID)
	}

	fmt.Printf("Installiere Build Essentials für %s...\n", os.Name)
	if err := InstallPackage(command, "", sudoPassword); err != nil {
		return fmt.Errorf("error installing Build Essentials: %v", err)
	}
	return nil
}