package steps

import (
	"bufio"
	"fmt"
	"miasma-installer/config"
	"miasma-installer/tui/styles"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"

	tea "github.com/charmbracelet/bubbletea"
)

type InstallModel struct {
	config       *config.InstallConfig
	Finished     bool
	status       string
	progress     []string
	err          error
	currentStep  int
	totalSteps   int
}

func NewInstallModel(disk string, enableLUKS bool, hostname string, username string, userPassword string, rootPassword string) InstallModel {
	return InstallModel{
		config: &config.InstallConfig{
			Disk:         disk,
			EnableLUKS:   enableLUKS,
			Hostname:     hostname,
			Username:     username,
			UserPassword: userPassword,
			RootPassword: rootPassword,
			Timezone:     "UTC",
			Locale:       "en_US.UTF-8",
		},
		status:      "Preparing installation...",
		progress:    []string{},
		currentStep: 0,
		totalSteps:  8,
	}
}

func (m InstallModel) Init() tea.Cmd {
	return m.startInstall()
}

type installCompleteMsg struct {
	err error
}

type installProgressMsg struct {
	step    int
	message string
}

func (m InstallModel) startInstall() tea.Cmd {
	return func() tea.Msg {
		if err := m.performInstall(); err != nil {
			return installCompleteMsg{err: err}
		}
		return installCompleteMsg{err: nil}
	}
}

func (m InstallModel) performInstall() error {
	m.updateProgress(1, "Partitioning disk...")
	if err := m.partitionDisk(); err != nil {
		return fmt.Errorf("partitioning failed: %w", err)
	}

	m.updateProgress(2, "Formatting partitions...")
	if err := m.formatPartitions(); err != nil {
		return fmt.Errorf("formatting failed: %w", err)
	}

	m.updateProgress(3, "Mounting filesystems...")
	if err := m.mountFilesystems(); err != nil {
		return fmt.Errorf("mounting failed: %w", err)
	}

	m.updateProgress(4, "Installing base system...")
	if err := m.installBase(); err != nil {
		return fmt.Errorf("base install failed: %w", err)
	}

	m.updateProgress(5, "Configuring system...")
	if err := m.configureSystem(); err != nil {
		return fmt.Errorf("configuration failed: %w", err)
	}

	m.updateProgress(6, "Installing bootloader...")
	if err := m.installBootloader(); err != nil {
		return fmt.Errorf("bootloader install failed: %w", err)
	}

	m.updateProgress(7, "Installing desktop and packages...")
	if err := m.installDesktop(); err != nil {
		return fmt.Errorf("desktop install failed: %w", err)
	}

	m.updateProgress(8, "Running post-install scripts...")
	if err := m.runPostInstallScripts(); err != nil {
		return fmt.Errorf("post-install scripts failed: %w", err)
	}

	return nil
}

func (m InstallModel) updateProgress(step int, message string) {
	m.currentStep = step
	m.status = message
	time.Sleep(100 * time.Millisecond)
}

func (m InstallModel) partitionDisk() error {
	disk := m.config.Disk

	wipeDisk := exec.Command("wipefs", "-af", disk)
	if err := wipeDisk.Run(); err != nil {
		return err
	}

	sgdisk := exec.Command("sgdisk", "-Z", disk)
	if err := sgdisk.Run(); err != nil {
		return err
	}

	createEFI := exec.Command("sgdisk", "-n", "1:0:+512M", "-t", "1:ef00", disk)
	if err := createEFI.Run(); err != nil {
		return err
	}

	createRoot := exec.Command("sgdisk", "-n", "2:0:0", "-t", "2:8300", disk)
	if err := createRoot.Run(); err != nil {
		return err
	}

	time.Sleep(1 * time.Second)
	exec.Command("partprobe", disk).Run()

	return nil
}

func (m InstallModel) formatPartitions() error {
	disk := m.config.Disk
	efiPart := disk + "1"
	rootPart := disk + "2"

	if strings.Contains(disk, "nvme") || strings.Contains(disk, "mmcblk") {
		efiPart = disk + "p1"
		rootPart = disk + "p2"
	}

	mkfsEFI := exec.Command("mkfs.fat", "-F32", efiPart)
	if err := mkfsEFI.Run(); err != nil {
		return err
	}

	if m.config.EnableLUKS {
		cryptsetup := exec.Command("cryptsetup", "luksFormat", "--type", "luks2", rootPart)
		cryptsetup.Stdin = strings.NewReader(m.config.RootPassword + "\n")
		if err := cryptsetup.Run(); err != nil {
			return err
		}

		cryptOpen := exec.Command("cryptsetup", "open", rootPart, "cryptroot")
		cryptOpen.Stdin = strings.NewReader(m.config.RootPassword + "\n")
		if err := cryptOpen.Run(); err != nil {
			return err
		}

		rootPart = "/dev/mapper/cryptroot"
	}

	mkfsBtrfs := exec.Command("mkfs.btrfs", "-f", rootPart)
	if err := mkfsBtrfs.Run(); err != nil {
		return err
	}

	return nil
}

func (m InstallModel) mountFilesystems() error {
	disk := m.config.Disk
	rootPart := disk + "2"
	efiPart := disk + "1"

	if strings.Contains(disk, "nvme") || strings.Contains(disk, "mmcblk") {
		efiPart = disk + "p1"
		rootPart = disk + "p2"
	}

	if m.config.EnableLUKS {
		rootPart = "/dev/mapper/cryptroot"
	}

	os.MkdirAll("/mnt", 0755)
	mount := exec.Command("mount", rootPart, "/mnt")
	if err := mount.Run(); err != nil {
		return err
	}

	btrfsOpts := "subvol=@,compress=zstd,noatime"
	for _, subvol := range []string{"@", "@home", "@var", "@snapshots"} {
		create := exec.Command("btrfs", "subvolume", "create", "/mnt/"+subvol)
		create.Run()
	}

	exec.Command("umount", "/mnt").Run()

	mount = exec.Command("mount", "-o", btrfsOpts, rootPart, "/mnt")
	if err := mount.Run(); err != nil {
		return err
	}

	os.MkdirAll("/mnt/home", 0755)
	os.MkdirAll("/mnt/var", 0755)
	os.MkdirAll("/mnt/.snapshots", 0755)
	os.MkdirAll("/mnt/boot", 0755)

	mountHome := exec.Command("mount", "-o", "subvol=@home,compress=zstd,noatime", rootPart, "/mnt/home")
	mountHome.Run()

	mountVar := exec.Command("mount", "-o", "subvol=@var,compress=zstd,noatime", rootPart, "/mnt/var")
	mountVar.Run()

	mountSnap := exec.Command("mount", "-o", "subvol=@snapshots,compress=zstd,noatime", rootPart, "/mnt/.snapshots")
	mountSnap.Run()

	mountEFI := exec.Command("mount", efiPart, "/mnt/boot")
	if err := mountEFI.Run(); err != nil {
		return err
	}

	return nil
}

func (m InstallModel) installBase() error {
	packages := []string{
		"base",
		"base-devel",
		"linux-hardened",
		"linux-firmware",
		"btrfs-progs",
		"neovim",
		"tmux",
		"git",
		"networkmanager",
		"sudo",
	}

	pacstrap := exec.Command("pacstrap", append([]string{"/mnt"}, packages...)...)
	pacstrap.Stdout = os.Stdout
	pacstrap.Stderr = os.Stderr
	if err := pacstrap.Run(); err != nil {
		return err
	}

	return nil
}

func (m InstallModel) configureSystem() error {
	genfstab := exec.Command("genfstab", "-U", "/mnt")
	fstab, err := genfstab.Output()
	if err != nil {
		return err
	}
	os.WriteFile("/mnt/etc/fstab", fstab, 0644)

	os.WriteFile("/mnt/etc/hostname", []byte(m.config.Hostname+"\n"), 0644)

	hosts := fmt.Sprintf("127.0.0.1\tlocalhost\n::1\t\tlocalhost\n127.0.1.1\t%s.localdomain\t%s\n",
		m.config.Hostname, m.config.Hostname)
	os.WriteFile("/mnt/etc/hosts", []byte(hosts), 0644)

	os.WriteFile("/mnt/etc/locale.gen", []byte("en_US.UTF-8 UTF-8\n"), 0644)
	chroot([]string{"locale-gen"})

	os.WriteFile("/mnt/etc/locale.conf", []byte("LANG=en_US.UTF-8\n"), 0644)

	chroot([]string{"ln", "-sf", "/usr/share/zoneinfo/UTC", "/etc/localtime"})
	chroot([]string{"hwclock", "--systohc"})

	useraddCmd := fmt.Sprintf("useradd -m -G wheel -s /bin/bash %s", m.config.Username)
	chroot([]string{"sh", "-c", useraddCmd})

	passwdCmd := fmt.Sprintf("echo '%s:%s' | chpasswd", m.config.Username, m.config.UserPassword)
	chroot([]string{"sh", "-c", passwdCmd})

	rootPasswdCmd := fmt.Sprintf("echo 'root:%s' | chpasswd", m.config.RootPassword)
	chroot([]string{"sh", "-c", rootPasswdCmd})

	sudoers := "%wheel ALL=(ALL:ALL) ALL\n"
	os.WriteFile("/mnt/etc/sudoers.d/wheel", []byte(sudoers), 0440)

	chroot([]string{"systemctl", "enable", "NetworkManager"})

	return nil
}

func (m InstallModel) installBootloader() error {
	chroot([]string{"bootctl", "install"})

	loaderConf := `default arch.conf
timeout 3
console-mode max
editor no
`
	os.WriteFile("/mnt/boot/loader/loader.conf", []byte(loaderConf), 0644)

	disk := m.config.Disk
	rootPart := disk + "2"
	if strings.Contains(disk, "nvme") || strings.Contains(disk, "mmcblk") {
		rootPart = disk + "p2"
	}

	rootUUID := ""
	if m.config.EnableLUKS {
		blkid := exec.Command("blkid", "-s", "UUID", "-o", "value", rootPart)
		output, _ := blkid.Output()
		rootUUID = strings.TrimSpace(string(output))
	} else {
		rootPart = "/dev/mapper/cryptroot"
		blkid := exec.Command("blkid", "-s", "UUID", "-o", "value", rootPart)
		output, _ := blkid.Output()
		rootUUID = strings.TrimSpace(string(output))
	}

	options := fmt.Sprintf("root=UUID=%s rootflags=subvol=@ rw", rootUUID)
	if m.config.EnableLUKS {
		cryptUUID := ""
		blkid := exec.Command("blkid", "-s", "UUID", "-o", "value", disk+"2")
		output, _ := blkid.Output()
		cryptUUID = strings.TrimSpace(string(output))
		options = fmt.Sprintf("cryptdevice=UUID=%s:cryptroot root=/dev/mapper/cryptroot rootflags=subvol=@ rw", cryptUUID)
	}

	entryConf := fmt.Sprintf(`title   Miasma OS
linux   /vmlinuz-linux-hardened
initrd  /initramfs-linux-hardened.img
options %s
`, options)
	os.WriteFile("/mnt/boot/loader/entries/arch.conf", []byte(entryConf), 0644)

	if m.config.EnableLUKS {
		mkinitcpio, _ := os.ReadFile("/mnt/etc/mkinitcpio.conf")
		newConf := strings.Replace(string(mkinitcpio),
			"HOOKS=(base udev autodetect modconf block filesystems keyboard fsck)",
			"HOOKS=(base udev autodetect keyboard keymap consolefont modconf block encrypt filesystems fsck)",
			1)
		os.WriteFile("/mnt/etc/mkinitcpio.conf", []byte(newConf), 0644)
		chroot([]string{"mkinitcpio", "-P"})
	}

	return nil
}

func (m InstallModel) installDesktop() error {
	chroot([]string{"pacman", "-Sy", "--noconfirm", "cosmic-session", "cosmic-greeter"})
	chroot([]string{"systemctl", "enable", "cosmic-greeter"})
	return nil
}

func (m InstallModel) runPostInstallScripts() error {
	scriptsDir := "./scripts"
	entries, err := os.ReadDir(scriptsDir)
	if err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}

	for _, entry := range entries {
		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".sh") {
			continue
		}

		scriptPath := filepath.Join(scriptsDir, entry.Name())
		scriptContent, err := os.ReadFile(scriptPath)
		if err != nil {
			return err
		}

		chrootScript := "/tmp/" + entry.Name()
		os.WriteFile("/mnt"+chrootScript, scriptContent, 0755)

		if output, err := chroot([]string{chrootScript}); err != nil {
			return fmt.Errorf("script %s failed: %w\nOutput: %s", entry.Name(), err, output)
		}

		os.Remove("/mnt" + chrootScript)
	}

	return nil
}

func chroot(args []string) (string, error) {
	cmd := exec.Command("arch-chroot", append([]string{"/mnt"}, args...)...)
	output, err := cmd.CombinedOutput()
	return string(output), err
}

func (m InstallModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case installCompleteMsg:
		if msg.err != nil {
			m.err = msg.err
			m.status = "Installation failed"
		} else {
			m.status = "Installation complete!"
		}
		m.Finished = true
		return m, nil
	}

	return m, nil
}

func (m InstallModel) View() string {
	var content strings.Builder

	content.WriteString(styles.TitleStyle.Render("⚙️  Installing Miasma OS"))
	content.WriteString("\n\n")

	progress := fmt.Sprintf("Step %d/%d", m.currentStep, m.totalSteps)
	content.WriteString(styles.ProgressTextStyle.Render(progress))
	content.WriteString("\n")

	bar := strings.Repeat("█", m.currentStep) + strings.Repeat("░", m.totalSteps-m.currentStep)
	content.WriteString(styles.ProgressBarStyle.Render(bar))
	content.WriteString("\n\n")

	content.WriteString(styles.SpinnerStyle.Render("● ") + m.status)
	content.WriteString("\n\n")

	if m.err != nil {
		errMsg := fmt.Sprintf("✗ Error: %v", m.err)
		content.WriteString(styles.ErrorBoxStyle.Render(errMsg))
		content.WriteString("\n\n")
		content.WriteString(styles.HelpStyle.Render("Press Ctrl+C to exit"))
	}

	if m.Finished && m.err == nil {
		success := "✓ Installation successful!\n\nYou can now reboot your system."
		content.WriteString(styles.BoxStyle.Render(success))
		content.WriteString("\n\n")
		content.WriteString(styles.RenderHelp("Ctrl+C", "Exit"))
	}

	return styles.AppStyle.Render(content.String())
}

func readLines(path string) ([]string, error) {
	file, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	var lines []string
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		lines = append(lines, scanner.Text())
	}
	return lines, scanner.Err()
}