package config

import (
	"fmt"
	"golang.org/x/crypto/bcrypt"
	"gopkg.in/yaml.v3"
	"os"
)

type (
	Configuration struct {
		Server   ServerConfiguration   `yaml:"server"`
		Database DatabaseConfiguration `yaml:"database"`
		Features FeaturesConfiguration `yaml:"features"`
		Path     PathConfiguration     `yaml:"path"`
	}

	PathConfiguration struct {
		Cache   string `yaml:"cache"`
		Storage string `yaml:"storage"`
		RSAKey  string `yaml:"rsa_key"`
	}

	ServerConfiguration struct {
		Port         int  `yaml:"port"`
		PingEndPoint bool `yaml:"ping"`
		Compress     bool `yaml:"compress"`
	}

	DatabaseConfiguration struct {
		URL string `yaml:"url"`
	}

	FeaturesConfiguration struct {
		AllowRegister    bool `yaml:"allow_register"`
		PasswordHashCost *int `yaml:"password_hash_cost"`
	}
)

func Load(path string) (Configuration, error) {
	configYamlContent, err := os.ReadFile(path)
	if err != nil {
		return Configuration{}, err
	}
	var config Configuration
	if err := yaml.Unmarshal(configYamlContent, &config); err != nil {
		return Configuration{}, err
	}
	if err := checkConfig(config); err != nil {
		return Configuration{}, err
	}
	return config, nil
}

func checkConfig(c Configuration) error {
	if c.Features.PasswordHashCost == nil {
		c.Features.PasswordHashCost = new(int)
		*c.Features.PasswordHashCost = bcrypt.DefaultCost
	} else if *c.Features.PasswordHashCost < bcrypt.MinCost && *c.Features.PasswordHashCost > bcrypt.MaxCost {
		return fmt.Errorf("password_hash_cost is not on the supported range (%d < x < %d)", bcrypt.MinCost, bcrypt.MaxCost)
	}
	if _, err := os.Stat(c.Path.Storage); err != nil {
		return nil
	}
	if _, err := os.Stat(c.Path.Cache); err != nil {
		return err
	}
	return nil
}