package config

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "log"
    "os"
    "path/filepath"
    "strings"
    "errors"
    //"crypto/rand"
    //"encoding/hex"
)

var APP_DIR = os.Getenv("HOME") + "/.tendermint"


/* Global & initialization */

var Config Config_

func init() {

    configFile := APP_DIR+"/config.json"

    // try to read configuration. if missing, write default
    configBytes, err := ioutil.ReadFile(configFile)
    if err != nil {
        defaultConfig.write(configFile)
        fmt.Println("Config file written to config.json. Please edit & run again")
        os.Exit(1)
        return
    }

    // try to parse configuration. on error, die
    Config = Config_{}
    err = json.Unmarshal(configBytes, &Config)
    if err != nil {
        log.Panicf("Invalid configuration file %s: %v", configFile, err)
    }
    err = Config.validate()
    if err != nil {
        log.Panicf("Invalid configuration file %s: %v", configFile, err)
    }
}


/* Default configuration */

var defaultConfig = Config_{
    Host:       "127.0.0.1",
    Port:       8770,
    Db:         DbConfig{
        Type:   "level",
        Dir:    APP_DIR+"/data",
    },
    Twilio:     TwilioConfig{
    },
}


/* Configuration types */

type Config_ struct {
    Host        string
    Port        int
    Db          DbConfig
    Twilio      TwilioConfig
}

type TwilioConfig struct {
    Sid         string
    Token       string
    From        string
    To          string
    MinInterval int
}

type DbConfig struct {
    Type        string
    Dir         string
}

func (cfg *Config_) validate() error {
    if cfg.Host == ""           { return errors.New("Host must be set") }
    if cfg.Port == 0            { return errors.New("Port must be set") }
    if cfg.Db.Type == ""        { return errors.New("Db.Type must be set") }
    return nil
}

func (cfg *Config_) bytes() []byte {
    configBytes, err := json.Marshal(cfg)
    if err != nil { panic(err) }
    return configBytes
}

func (cfg *Config_) write(configFile string) {
    if strings.Index(configFile, "/") != -1 {
        err := os.MkdirAll(filepath.Dir(configFile), 0700)
        if err != nil { panic(err) }
    }
    err := ioutil.WriteFile(configFile, cfg.bytes(), 0600)
    if err != nil {
        panic(err)
    }
}

/* TODO: generate priv/pub keys
func generateKeys() string {
    bytes := &[30]byte{}
    rand.Read(bytes[:])
    return hex.EncodeToString(bytes[:])
}
*/