package db

import (
	"fmt"
	"os"
	"time"

	"gopkg.in/yaml.v3"
)

const (
	DefaultBatchSize     = 100
	DefaultFlushInterval = time.Minute
	DefaultTableName     = "results"
	DefaultDatabaseName  = "httpx"
	EnvConnectionString  = "HTTPX_DB_CONNECTION_STRING"
)

type Config struct {
	Type             DatabaseType  `yaml:"type"`
	ConnectionString string        `yaml:"connection-string"`
	DatabaseName     string        `yaml:"database-name"`
	TableName        string        `yaml:"table-name"`
	BatchSize        int           `yaml:"batch-size"`
	FlushInterval    time.Duration `yaml:"flush-interval"`
	OmitRaw          bool          `yaml:"omit-raw"`
}

func (c *Config) Validate() error {
	if !c.Type.IsValid() {
		return fmt.Errorf("invalid database type: %s (supported: %v)", c.Type, SupportedDatabases())
	}

	if c.ConnectionString == "" {
		return fmt.Errorf("connection string is required")
	}

	return nil
}

func (c *Config) ApplyDefaults() {
	if c.DatabaseName == "" {
		c.DatabaseName = DefaultDatabaseName
	}

	if c.TableName == "" {
		c.TableName = DefaultTableName
	}

	if c.BatchSize <= 0 {
		c.BatchSize = DefaultBatchSize
	}

	if c.FlushInterval <= 0 {
		c.FlushInterval = DefaultFlushInterval
	}
}

func LoadConfigFromFile(configPath string) (*Config, error) {
	data, err := os.ReadFile(configPath)
	if err != nil {
		return nil, fmt.Errorf("failed to read config file: %w", err)
	}

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

	if cfg.ConnectionString == "" {
		cfg.ConnectionString = os.Getenv(EnvConnectionString)
	}

	cfg.ApplyDefaults()

	if err := cfg.Validate(); err != nil {
		return nil, err
	}

	return &cfg, nil
}

type Options struct {
	Enabled          bool
	ConfigFile       string
	Type             string
	ConnectionString string
	DatabaseName     string
	TableName        string
	BatchSize        int
	OmitRaw          bool
}

func (o *Options) ToConfig() (*Config, error) {
	cfg := &Config{
		Type:             DatabaseType(o.Type),
		ConnectionString: o.ConnectionString,
		DatabaseName:     o.DatabaseName,
		TableName:        o.TableName,
		BatchSize:        o.BatchSize,
		OmitRaw:          o.OmitRaw,
	}

	cfg.ApplyDefaults()

	if err := cfg.Validate(); err != nil {
		return nil, err
	}

	return cfg, nil
}