// pkg/config/config.go
package config

import (
	"fmt"
	"os"

	"git.linuxforward.com/byom/byom-golang-lib/pkg/errors"
	"github.com/sirupsen/logrus"
	"gopkg.in/yaml.v3"
)

type Config struct {
	App            *App            `yaml:"app"`
	Server         *Server         `yaml:"server"`
	Database       *Database       `yaml:"database"`
	Log            *Log            `yaml:"log"`
	Storage        *Storage        `yaml:"storage"`
	CloudComputing *CloudComputing `yaml:"cloud_computing,omitempty"`
	SocialNetworks *SocialNetworks `yaml:"social_networks,omitempty"`
}

func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type plain Config
	err := unmarshal((*plain)(c))
	if err != nil {
		return err
	}
	if c.App == nil {
		return errors.NewConfigError("app", errors.ErrInvalidInput)
	}

	// Conditional validation based on app name
	switch c.App.Name {
	case "design":
		if c.CloudComputing == nil {
			return errors.NewConfigError("cloud_computing", errors.ErrInvalidInput)
		}
	case "trends":
		if c.SocialNetworks == nil {
			return errors.NewConfigError("social_networks", errors.ErrInvalidInput)
		}
	}
	return nil
}

type App struct {
	Name        string `yaml:"name"`
	Environment string `yaml:"environment"`
}

func (c *App) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type plain App
	err := unmarshal((*plain)(c))
	if err != nil {
		return err
	}
	if c.Name == "" {
		return errors.NewConfigError("app.name", errors.ErrInvalidInput)
	}
	if c.Environment == "" {
		c.Environment = "development"
	}
	// Validate app name
	validNames := map[string]bool{"core": true, "design": true, "trends": true}
	if !validNames[c.Name] {
		return errors.NewConfigError("app.name", errors.ErrInvalidInput)
	}
	return nil
}

type Server struct {
	Port           int      `yaml:"port"`
	RequestTimeout int      `yaml:"request_timeout"` // in seconds
	AllowedOrigins []string `yaml:"allowed_origins"`
}

func (c *Server) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type plain Server
	err := unmarshal((*plain)(c))
	if err != nil {
		return err
	}
	if c.Port == 0 {
		c.Port = 8080
	}
	if c.RequestTimeout == 0 {
		c.RequestTimeout = 30
	}
	return nil
}

type Database struct {
	Path            string   `yaml:"path"`
	MaxOpenConns    int      `yaml:"max_open_conns"`
	MaxIdleConns    int      `yaml:"max_idle_conns"`
	ConnMaxLifetime int      `yaml:"conn_max_lifetime"`
	Pragmas         []string `yaml:"pragmas"`
}

func (c *Database) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type plain Database
	err := unmarshal((*plain)(c))
	if err != nil {
		return err
	}
	if c.Path == "" {
		return errors.NewConfigError("database.path", errors.ErrInvalidInput)
	}
	if c.MaxOpenConns == 0 {
		c.MaxOpenConns = 1 // SQLite recommendation
	}
	if c.MaxIdleConns == 0 {
		c.MaxIdleConns = 1
	}
	if c.ConnMaxLifetime == 0 {
		c.ConnMaxLifetime = 300 // 5 minutes
	}
	return nil
}

type Log struct {
	Level   string `yaml:"level"`
	Format  string `yaml:"format"` // "json" or "text"
	NoColor bool   `yaml:"no_color"`
}

func (c *Log) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type plain Log
	err := unmarshal((*plain)(c))
	if err != nil {
		return err
	}
	if c.Level == "" {
		c.Level = "info"
	}
	if c.Format == "" {
		c.Format = "text"
	}
	// Validate log level
	_, err = logrus.ParseLevel(c.Level)
	if err != nil {
		return errors.NewConfigError("log.level", err)
	}
	return nil
}

type Storage struct {
	Endpoint        string `yaml:"endpoint"`
	AccessKeyID     string `yaml:"access_key_id"`
	SecretAccessKey string `yaml:"secret_access_key"`
	UseSSL          bool   `yaml:"use_ssl"`
	BucketName      string `yaml:"bucket_name"`
}

func (c *Storage) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type plain Storage
	err := unmarshal((*plain)(c))
	if err != nil {
		return err
	}
	if c.Endpoint == "" {
		return errors.NewConfigError("storage.endpoint", errors.ErrInvalidInput)
	}
	if c.AccessKeyID == "" {
		return errors.NewConfigError("storage.access_key_id", errors.ErrInvalidInput)
	}
	if c.SecretAccessKey == "" {
		return errors.NewConfigError("storage.secret_access_key", errors.ErrInvalidInput)
	}
	if c.BucketName == "" {
		return errors.NewConfigError("storage.bucket_name", errors.ErrInvalidInput)
	}
	return nil
}

type CloudComputing struct {
	Provider    string `yaml:"provider"`
	Region      string `yaml:"region"`
	MaxCapacity int    `yaml:"max_capacity"`
}

func (c *CloudComputing) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type plain CloudComputing
	err := unmarshal((*plain)(c))
	if err != nil {
		return err
	}
	if c.Provider == "" {
		return errors.NewConfigError("cloud_computing.provider", errors.ErrInvalidInput)
	}
	if c.Region == "" {
		return errors.NewConfigError("cloud_computing.region", errors.ErrInvalidInput)
	}
	if c.MaxCapacity <= 0 {
		return errors.NewConfigError("cloud_computing.max_capacity", errors.ErrInvalidInput)
	}
	return nil
}

type SocialNetworks struct {
	Networks []SocialNetwork `yaml:"networks"`
}

type SocialNetwork struct {
	Name     string `yaml:"name"`
	APIKey   string `yaml:"api_key"`
	APIToken string `yaml:"api_token"`
}

func (c *SocialNetworks) UnmarshalYAML(unmarshal func(interface{}) error) error {
	type plain SocialNetworks
	err := unmarshal((*plain)(c))
	if err != nil {
		return err
	}
	if len(c.Networks) == 0 {
		return errors.NewConfigError("social_networks", errors.ErrInvalidInput)
	}
	for i, network := range c.Networks {
		section := fmt.Sprintf("social_networks.networks[%d]", i)
		if network.Name == "" {
			return errors.NewConfigError(section+".name", errors.ErrInvalidInput)
		}
		if network.APIKey == "" {
			return errors.NewConfigError(section+".api_key", errors.ErrInvalidInput)
		}
		if network.APIToken == "" {
			return errors.NewConfigError(section+".api_token", errors.ErrInvalidInput)
		}
	}
	return nil
}

func ReadConfig(configPath string) (*Config, error) {
	data, err := os.ReadFile(configPath)
	if err != nil {
		return nil, errors.NewConfigError("read", err)
	}

	config := &Config{}
	err = yaml.Unmarshal(data, config)
	if err != nil {
		return nil, errors.NewConfigError("parse", err)
	}

	return config, nil
}