package config

import (
	"encoding/json"
	"fmt"
	"os"
	"time"

	"github.com/sirupsen/logrus"
)

type ExportMode int64

const (
	ExportNative = iota
	ExportUnix
)

func exportModeFromStr(val string) ExportMode {
	switch val {
	case "native":
		return ExportNative
	case "unix":
		return ExportUnix
	default:
		return ExportNative
	}
}

type TelegramConfig struct {
	ChannelID int64  `json:"channel_id"`
	Token     string `json:"token"`
}

type LogConfig struct {
	Level logrus.Level
}

type jsonLogConfig struct {
	Level string `json:"level"`
}

type ExportConfig struct {
	Mode     ExportMode
	UnixSock string
}

type jsonExportConfig struct {
	Mode     string `json:"mode"`
	UnixSock string `json:"sock_path"`
}

type Config struct {
	Telegram         *TelegramConfig
	PollingFrequency time.Duration
	Hostname         string
	Log              LogConfig
	Export           ExportConfig
}

type jsonConfig struct {
	Telegram         *TelegramConfig  `json:"telegram"`
	PollingFrequency int64            `json:"polling_frequency"`
	Hostname         string           `json:"hostname"`
	Log              jsonLogConfig    `json:"log"`
	Export           jsonExportConfig `json:"export"`
}

func parseLevel(lvlStr string) logrus.Level {
	for _, lvl := range logrus.AllLevels {
		if lvl.String() == lvlStr {
			return lvl
		}
	}
	return logrus.InfoLevel
}

func New(filepath string) (*Config, error) {
	content, err := os.ReadFile(filepath)
	if err != nil {
		return nil, fmt.Errorf("failed to read config file %q: %w", filepath, err)
	}
	var jsonConf jsonConfig
	if err := json.Unmarshal(content, &jsonConf); err != nil {
		return nil, fmt.Errorf("failed to parse config file: %w", err)
	}

	return &Config{
		Telegram:         jsonConf.Telegram,
		PollingFrequency: time.Duration(jsonConf.PollingFrequency) * time.Second,
		Hostname:         jsonConf.Hostname,
		Log: LogConfig{
			Level: parseLevel(jsonConf.Log.Level),
		},
		Export: ExportConfig{
			UnixSock: jsonConf.Export.UnixSock,
			Mode:     exportModeFromStr(jsonConf.Export.Mode),
		},
	}, nil
}