package main

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
)

type AppConfig struct {
	Storage struct {
		AppDataDir         string `json:"app_data_dir"`
		InstallDir         string `json:"install_dir"`
		InstancesDir       string `json:"instances_dir"`
		BackupDir          string `json:"backup_dir"`
		ConfigTemplatesDir string `json:"config_templates_dir"`
	} `json:"storage"`

	Daemon struct {
		ListenAddress string `json:"listen_address"`
	}

	Instances map[string]VsServerConfigOptions `json:"instances"`
}

func CreateConfigWithDefaults(configPath string) *AppConfig {
	home, _ := os.UserHomeDir()
	basePath := filepath.Join(home, ".local", "share", "vssm")

	cfg := &AppConfig{}
	cfg.Storage.AppDataDir = basePath
	cfg.Storage.InstallDir = filepath.Join(basePath, "installs")
	cfg.Storage.InstancesDir = filepath.Join(basePath, "instances")
	cfg.Storage.BackupDir = filepath.Join(basePath, "backups")
	cfg.Storage.ConfigTemplatesDir = filepath.Join(basePath, "config_templates")

	cfg.Daemon.ListenAddress = "127.0.0.1:12345"

	cfg.Instances = make(map[string]VsServerConfigOptions)

	return cfg
}

func LoadOrCreateConfig(configPath string) (*AppConfig, error) {
	if _, err := os.Stat(configPath); os.IsNotExist(err) {
		cfg := CreateConfigWithDefaults(configPath)

		if err := os.MkdirAll(filepath.Dir(configPath), 0755); err != nil {
			return nil, fmt.Errorf("Failed to create config directory: %w", err)
		}

		data, err := json.MarshalIndent(cfg, "", "  ")
		if err != nil {
			return nil, err
		}

		if err := os.WriteFile(configPath, data, 0644); err != nil {
			return nil, fmt.Errorf("Failed to write config file at %s\n", configPath)
		}
	}

	data, err := os.ReadFile(configPath)
	if err != nil {
		return nil, err
	}

	var cfg AppConfig
	if err := json.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("Invalid JSON layout in config file: %w", err)
	}

	dirs := []string{
		cfg.Storage.AppDataDir,
		cfg.Storage.InstallDir,
		cfg.Storage.InstancesDir,
		cfg.Storage.BackupDir,
		cfg.Storage.ConfigTemplatesDir,
	}
	for _, dir := range dirs {
		if err := os.MkdirAll(dir, 0755); err != nil {
			return nil, fmt.Errorf("Failed creating workspace directory %s: %w", dir, err)
		}
	}

	return &cfg, nil
}