package conf

import (
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"path"
	"strings"

	"github.com/zeromicro/go-zero/core/mapping"
)

var loaders = map[string]func([]byte, interface{}) error{
	".json": LoadFromJsonBytes,
	".toml": LoadFromTomlBytes,
	".yaml": LoadFromYamlBytes,
	".yml":  LoadFromYamlBytes,
}

// Load loads config into v from file, .json, .yaml and .yml are acceptable.
func Load(file string, v interface{}, opts ...Option) error {
	content, err := ioutil.ReadFile(file)
	if err != nil {
		return err
	}

	loader, ok := loaders[strings.ToLower(path.Ext(file))]
	if !ok {
		return fmt.Errorf("unrecognized file type: %s", file)
	}

	var opt options
	for _, o := range opts {
		o(&opt)
	}

	if opt.env {
		return loader([]byte(os.ExpandEnv(string(content))), v)
	}

	return loader(content, v)
}

// LoadConfig loads config into v from file, .json, .yaml and .yml are acceptable.
// Deprecated: use Load instead.
func LoadConfig(file string, v interface{}, opts ...Option) error {
	return Load(file, v, opts...)
}

// LoadFromJsonBytes loads config into v from content json bytes.
func LoadFromJsonBytes(content []byte, v interface{}) error {
	return mapping.UnmarshalJsonBytes(content, v)
}

// LoadConfigFromJsonBytes loads config into v from content json bytes.
// Deprecated: use LoadFromJsonBytes instead.
func LoadConfigFromJsonBytes(content []byte, v interface{}) error {
	return LoadFromJsonBytes(content, v)
}

// LoadFromTomlBytes loads config into v from content toml bytes.
func LoadFromTomlBytes(content []byte, v interface{}) error {
	return mapping.UnmarshalTomlBytes(content, v)
}

// LoadFromYamlBytes loads config into v from content yaml bytes.
func LoadFromYamlBytes(content []byte, v interface{}) error {
	return mapping.UnmarshalYamlBytes(content, v)
}

// LoadConfigFromYamlBytes loads config into v from content yaml bytes.
// Deprecated: use LoadFromYamlBytes instead.
func LoadConfigFromYamlBytes(content []byte, v interface{}) error {
	return LoadFromYamlBytes(content, v)
}

// MustLoad loads config into v from path, exits on error.
func MustLoad(path string, v interface{}, opts ...Option) {
	if err := Load(path, v, opts...); err != nil {
		log.Fatalf("error: config file %s, %s", path, err.Error())
	}
}