package config

import (
	"fmt"
	"os"
	"path/filepath"

	"gopkg.in/yaml.v3"
)

// Config lives at .verstak/config.yml inside the vault.
type Config struct {
	Engine  EngineConfig  `yaml:"engine"`
	Sync    SyncConfig    `yaml:"sync"`
	Browser BrowserConfig `yaml:"browser"`
}

type EngineConfig struct {
	Version   int    `yaml:"version"`
	VaultID   string `yaml:"vault_id"`
	CreatedAt string `yaml:"created_at"`
	VaultRoot string `yaml:"vault_root"`
}

type SyncConfig struct {
	ServerURL    string `yaml:"server_url"`
	APIKey       string `yaml:"api_key"`
	DeviceID     string `yaml:"device_id"`
	AutoSync     bool   `yaml:"auto_sync"`
	SyncInterval int    `yaml:"sync_interval"`
}

type BrowserConfig struct {
	Enabled   bool `yaml:"enabled"`
	LocalPort int  `yaml:"local_port"`
}

// Load reads .verstak/config.yml from the vault root.
func Load(vaultRoot string) (*Config, error) {
	path := filepath.Join(vaultRoot, ".verstak", "config.yml")
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("read config: %w", err)
	}
	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parse config: %w", err)
	}
	return &cfg, nil
}

// Save writes the config file.
func Save(vaultRoot string, cfg *Config) error {
	path := filepath.Join(vaultRoot, ".verstak", "config.yml")
	dir := filepath.Dir(path)
	if err := os.MkdirAll(dir, 0o750); err != nil {
		return err
	}
	data, err := yaml.Marshal(cfg)
	if err != nil {
		return err
	}
	return os.WriteFile(path, data, 0o640)
}

// MetaPath returns the path inside the vault for sqlite db etc.
func MetaDir(vaultRoot string) string {
	return filepath.Join(vaultRoot, ".verstak")
}

// DeviceTokenPath returns the path to the device_token file.
func DeviceTokenPath(vaultRoot string) string {
	return filepath.Join(vaultRoot, ".verstak", "device_token.json")
}

// SaveDeviceToken writes the device token to a separate file with 0600 perms.
func SaveDeviceToken(vaultRoot, token string) error {
	path := DeviceTokenPath(vaultRoot)
	dir := filepath.Dir(path)
	if err := os.MkdirAll(dir, 0o750); err != nil {
		return err
	}
	data := fmt.Sprintf(`{"device_token":%q}`, token)
	return os.WriteFile(path, []byte(data), 0o600)
}

// LoadDeviceToken reads the device token from the separate file.
func LoadDeviceToken(vaultRoot string) string {
	path := DeviceTokenPath(vaultRoot)
	data, err := os.ReadFile(path)
	if err != nil {
		return ""
	}
	var v struct {
		DeviceToken string `yaml:"device_token"`
	}
	if err := yaml.Unmarshal(data, &v); err != nil {
		return ""
	}
	return v.DeviceToken
}

// RemoveDeviceToken deletes the device token file.
func RemoveDeviceToken(vaultRoot string) error {
	path := DeviceTokenPath(vaultRoot)
	return os.Remove(path)
}