// Package config handles configuration loading.
package config

import (
	"fmt"
	"os"

	"gopkg.in/yaml.v3"
)

// Config holds all application configuration.
type Config struct {
	Server   ServerConfig   `yaml:"server"`
	Database DatabaseConfig `yaml:"database"`
	Storage  StorageConfig  `yaml:"storage"`
	Schemas  SchemasConfig  `yaml:"schemas"`
	FreeCAD  FreeCADConfig  `yaml:"freecad"`
	Odoo     OdooConfig     `yaml:"odoo"`
}

// ServerConfig holds HTTP server settings.
type ServerConfig struct {
	Host    string `yaml:"host"`
	Port    int    `yaml:"port"`
	BaseURL string `yaml:"base_url"`
}

// DatabaseConfig holds PostgreSQL connection settings.
type DatabaseConfig struct {
	Host           string `yaml:"host"`
	Port           int    `yaml:"port"`
	Name           string `yaml:"name"`
	User           string `yaml:"user"`
	Password       string `yaml:"password"`
	SSLMode        string `yaml:"sslmode"`
	MaxConnections int    `yaml:"max_connections"`
}

// StorageConfig holds MinIO connection settings.
type StorageConfig struct {
	Endpoint  string `yaml:"endpoint"`
	AccessKey string `yaml:"access_key"`
	SecretKey string `yaml:"secret_key"`
	Bucket    string `yaml:"bucket"`
	UseSSL    bool   `yaml:"use_ssl"`
	Region    string `yaml:"region"`
}

// SchemasConfig holds schema loading settings.
type SchemasConfig struct {
	Directory string `yaml:"directory"`
	Default   string `yaml:"default"`
}

// FreeCADConfig holds FreeCAD integration settings.
type FreeCADConfig struct {
	URIScheme  string `yaml:"uri_scheme"`
	Executable string `yaml:"executable"`
}

// OdooConfig holds Odoo ERP integration settings.
type OdooConfig struct {
	Enabled  bool   `yaml:"enabled"`
	URL      string `yaml:"url"`
	Database string `yaml:"database"`
	Username string `yaml:"username"`
	APIKey   string `yaml:"api_key"`
}

// Load reads configuration from a YAML file.
func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("reading config file: %w", err)
	}

	// Expand environment variables
	data = []byte(os.ExpandEnv(string(data)))

	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parsing config YAML: %w", err)
	}

	// Apply defaults
	if cfg.Server.Port == 0 {
		cfg.Server.Port = 8080
	}
	if cfg.Database.Port == 0 {
		cfg.Database.Port = 5432
	}
	if cfg.Database.SSLMode == "" {
		cfg.Database.SSLMode = "require"
	}
	if cfg.Database.MaxConnections == 0 {
		cfg.Database.MaxConnections = 10
	}
	if cfg.Storage.Region == "" {
		cfg.Storage.Region = "us-east-1"
	}
	if cfg.Schemas.Directory == "" {
		cfg.Schemas.Directory = "/etc/silo/schemas"
	}
	if cfg.FreeCAD.URIScheme == "" {
		cfg.FreeCAD.URIScheme = "silo"
	}

	// Override with environment variables
	if v := os.Getenv("SILO_DB_HOST"); v != "" {
		cfg.Database.Host = v
	}
	if v := os.Getenv("SILO_DB_NAME"); v != "" {
		cfg.Database.Name = v
	}
	if v := os.Getenv("SILO_DB_USER"); v != "" {
		cfg.Database.User = v
	}
	if v := os.Getenv("SILO_DB_PASSWORD"); v != "" {
		cfg.Database.Password = v
	}
	if v := os.Getenv("SILO_MINIO_ENDPOINT"); v != "" {
		cfg.Storage.Endpoint = v
	}
	if v := os.Getenv("SILO_MINIO_ACCESS_KEY"); v != "" {
		cfg.Storage.AccessKey = v
	}
	if v := os.Getenv("SILO_MINIO_SECRET_KEY"); v != "" {
		cfg.Storage.SecretKey = v
	}

	return &cfg, nil
}