package config

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

const defaultFile = "bot_config.json"

// Config holds bot configuration settings
type Config struct {
	SummaryTime    string `json:"summary_time"`    // HH:MM format
	SummaryChannel string `json:"summary_channel"` // Channel ID
	Timezone       string `json:"timezone"`
}

// Manager handles configuration persistence
type Manager struct {
	config   Config
	filename string
}

// New creates a new config manager
func New(filename string) (*Manager, error) {
	if filename == "" {
		filename = defaultFile
	}

	cm := &Manager{
		filename: filename,
		config: Config{
			SummaryTime:    "09:00",
			SummaryChannel: "",
			Timezone:       "America/New_York",
		},
	}

	if err := cm.load(); err != nil {
		if !os.IsNotExist(err) {
			return nil, fmt.Errorf("failed to load config: %w", err)
		}
	}

	return cm, nil
}

func (cm *Manager) load() error {
	data, err := os.ReadFile(cm.filename)
	if err != nil {
		return err
	}

	return json.Unmarshal(data, &cm.config)
}

func (cm *Manager) save() error {
	data, err := json.MarshalIndent(cm.config, "", "  ")
	if err != nil {
		return fmt.Errorf("failed to marshal config: %w", err)
	}

	return os.WriteFile(cm.filename, data, 0644)
}

// SetSummaryTime sets the time for daily summaries
func (cm *Manager) SetSummaryTime(timeStr string) error {
	if _, err := time.Parse("15:04", timeStr); err != nil {
		return fmt.Errorf("invalid time format, use HH:MM: %w", err)
	}

	cm.config.SummaryTime = timeStr
	return cm.save()
}

// SetSummaryChannel sets the channel for daily summaries
func (cm *Manager) SetSummaryChannel(channelID string) error {
	cm.config.SummaryChannel = channelID
	return cm.save()
}

// Get returns the current configuration
func (cm *Manager) Get() Config {
	return cm.config
}