package install

import (
    "encoding/json"
    "errors"
    "fmt"
    "io"
    "net/http"
    "os"
    "os/exec"
    "path/filepath"
    "strings"

    "gitea.home.musaberdem.de/musabe24/ginie/internal/repos"
)

type Installed struct {
    Name      string `json:"name"`
    Version   string `json:"version"`
    AssetName string `json:"asset"`
    AssetURL  string `json:"url"`
}

func configPath() (string, error) {
    home, err := os.UserHomeDir()
    if err != nil {
        return "", err
    }

    dir := filepath.Join(home, ".config", "ginie")
    os.MkdirAll(dir, 0755)

    return filepath.Join(dir, "installed.json"), nil
}

func LoadInstalled() ([]Installed, error) {
    path, _ := configPath()
    data, err := os.ReadFile(path)

    if os.IsNotExist(err) {
        return []Installed{}, nil
    }
    if err != nil {
        return nil, err
    }

    var out []Installed
    err = json.Unmarshal(data, &out)
    return out, err
}

func SaveInstalled(list []Installed) error {
    path, _ := configPath()
    data, err := json.MarshalIndent(list, "", "  ")
    if err != nil {
        return err
    }
    return os.WriteFile(path, data, 0644)
}

func parseNameVersion(input string) (name string, version string) {
    parts := strings.Split(input, ":")
    if len(parts) == 1 {
        return parts[0], "" // keine Version
    }
    return parts[0], parts[1]
}

func Install(pkg string) error {
    name, version := parseNameVersion(pkg)

    // Repo suchen
    all, err := repos.LoadRepos()
    if err != nil {
        return err
    }

    var repo repos.Repo
    found := false
    for _, r := range all {
        if r.Name == name {
            repo = r
            found = true
            break
        }
    }
    if !found {
        return errors.New("Repo nicht gefunden. Nutze: ginie add <URL>")
    }

    // Release-API-URL
    api := ""
    if version == "" {
        api = fmt.Sprintf("https://api.github.com/repos/%s/%s/releases/latest", repo.Owner, repo.Name)
    } else {
        api = fmt.Sprintf("https://api.github.com/repos/%s/%s/releases/tags/%s", repo.Owner, repo.Name, version)
    }

    // API abfragen
    resp, err := http.Get(api)
    if err != nil {
        return err
    }
    defer resp.Body.Close()

    if resp.StatusCode != 200 {
        return fmt.Errorf("GitHub API Fehler: %s", resp.Status)
    }

    var release struct {
        TagName string `json:"tag_name"`
        Assets  []struct {
            Name        string `json:"name"`
            BrowserDownloadURL string `json:"browser_download_url"`
        } `json:"assets"`
    }

    if err := json.NewDecoder(resp.Body).Decode(&release); err != nil {
        return err
    }

    if len(release.Assets) == 0 {
        return errors.New("Release hat keine Assets")
    }

    // Asset-Auswahl
    fmt.Println("Verfügbare Assets:")
    for i, a := range release.Assets {
        fmt.Printf("[%d] %s\n", i, a.Name)
    }

    fmt.Print("Wähle Asset-Nummer: ")
    var choice int
    fmt.Scan(&choice)

    if choice < 0 || choice >= len(release.Assets) {
        return errors.New("Ungültige Auswahl")
    }

    asset := release.Assets[choice]

    // Datei herunterladen
    fmt.Println("Lade herunter:", asset.Name)

    out, err := os.Create(asset.Name)
    if err != nil {
        return err
    }
    defer out.Close()

    dl, err := http.Get(asset.BrowserDownloadURL)
    if err != nil {
        return err
    }
    defer dl.Body.Close()

    _, err = io.Copy(out, dl.Body)
    if err != nil {
        return err
    }

    fmt.Println("Download abgeschlossen.")

    // Installation (unterstützt .deb)
    if strings.HasSuffix(asset.Name, ".deb") {
        fmt.Println("Installiere .deb Datei…")
        cmd := exec.Command("sudo", "dpkg", "-i", asset.Name)
        cmd.Stdout = os.Stdout
        cmd.Stderr = os.Stderr
        err := cmd.Run()
        if err != nil {
            fmt.Println("Package konnte nicht installiert werden.")
        }
        err = os.Remove(asset.Name)
        if err != nil {
            fmt.Println("Package konnte nicht gelöscht werden.")
        }
        return err
    }

    return errors.New("Asset-Typ wird noch nicht unterstützt")
}