package main

import (
	"fmt"
	"path/filepath"
	"spitfire-installer/spm"
)

// Installer manages the download, decompression, and installation processes.
type Installer struct {
	// Progress info from SPM
	Progress int
	Task     string

	// Internal states
	IsDownloading bool
	IsInstalling  bool
	DoneDownload  bool
	DoneInstall   bool
	LastError     error

	// Paths
	DownloadDir string
	TempDir     string
}

// NewInstaller creates a new Installer with initial state.
func NewInstaller() *Installer {
	return &Installer{}
}

// StartDownloadDecompress starts the download and decompression in a background goroutine.
func (inst *Installer) StartDownloadDecompress() {
	inst.IsDownloading = true
	go func() {
		defer func() {
			inst.IsDownloading = false
			inst.DoneDownload = (inst.LastError == nil)
		}()

		// Prepare download directory
		spm.UpdateProgress(0, "Preparing to download...")
		inst.DownloadDir = spm.GetTempDownloadDir()

		// Download APPINDEX
		appIndexPath := filepath.Join(inst.DownloadDir, "APPINDEX")
		spm.UpdateProgress(0, "Downloading APPINDEX")
		if err := spm.DownloadAppIndex(appIndexPath); err != nil {
			inst.LastError = err
			return
		}

		// Download package
		packageName := "spitfire-browser"
		release := "nightly"
		spm.UpdateProgress(0, "Downloading package...")
		if err := spm.DownloadPackageFromAppIndex(appIndexPath, packageName, release, inst.DownloadDir); err != nil {
			inst.LastError = err
			return
		}

		// Decompress
		spm.UpdateProgress(0, "Decompressing...")
		packagePath := filepath.Join(inst.DownloadDir, "browser-amd64-nightly-linux.tar.gz")
		tempDir, err := spm.DecompressToTemp(packagePath)
		if err != nil {
			inst.LastError = err
			return
		}

		inst.TempDir = tempDir
	}()
}

// FinalInstall moves files to the final install directory in a background goroutine.
func (inst *Installer) FinalInstall() {
	if !inst.DoneDownload {
		inst.LastError = fmt.Errorf("Cannot install: download and decompression are not complete")
		return
	}

	inst.IsInstalling = true
	go func() {
		defer func() {
			inst.IsInstalling = false
			inst.DoneInstall = (inst.LastError == nil)
		}()

		// Move files to install directory
		spm.UpdateProgress(0, "Installing...")
		installDir := "/home/czmisacz/Stažené/spitfire"
		if err := spm.MoveFilesToInstallDir(inst.TempDir, installDir); err != nil {
			inst.LastError = err
			return
		}

		spm.UpdateProgress(100, "Installation complete!")
	}()
}

// PollProgress fetches the latest progress and task from SPM.
func (inst *Installer) PollProgress() {
	p, t := spm.GetProgress()
	inst.Progress, inst.Task = p, t
}