package reminder

import (
	"fmt"
	"regexp"
	"strconv"
	"strings"
	"time"

	"git.nakama.town/fmartingr/butterrobot/internal/model"
	"git.nakama.town/fmartingr/butterrobot/internal/plugin"
)

// Duration regex patterns to match reminders
var (
	remindMePattern = regexp.MustCompile(`(?i)^!remindme\s(\d+)(y|mo|d|h|m|s)$`)
)

// ReminderCreator is an interface for creating reminders
type ReminderCreator interface {
	CreateReminder(platform, channelID, messageID, replyToID, userID, username, content string, triggerAt time.Time) (*model.Reminder, error)
}

// Reminder is a plugin that sets reminders for messages
type Reminder struct {
	plugin.BasePlugin
	creator ReminderCreator
}

// New creates a new Reminder plugin
func New(creator ReminderCreator) *Reminder {
	return &Reminder{
		BasePlugin: plugin.BasePlugin{
			ID:             "reminder.remindme",
			Name:           "Remind Me",
			Help:           "Reply to a message with `!remindme <duration>` to set a reminder (e.g., `!remindme 2d` for 2 days, `!remindme 1y` for 1 year).",
			ConfigRequired: false,
		},
		creator: creator,
	}
}

// OnMessage processes incoming messages
func (r *Reminder) OnMessage(msg *model.Message, config map[string]interface{}) []*model.Message {
	// Only process replies to messages
	if msg.ReplyTo == "" {
		return nil
	}

	// Check if the message is a reminder command
	match := remindMePattern.FindStringSubmatch(msg.Text)
	if match == nil {
		return nil
	}

	// Parse the duration
	amount, err := strconv.Atoi(match[1])
	if err != nil {
		return []*model.Message{
			{
				Text:    "Invalid duration format. Please use a number followed by y (years), mo (months), d (days), h (hours), m (minutes), or s (seconds).",
				Chat:    msg.Chat,
				Channel: msg.Channel,
				Author:  "bot",
				FromBot: true,
				Date:    time.Now(),
				ReplyTo: msg.ID,
			},
		}
	}

	// Calculate the trigger time
	var duration time.Duration
	unit := match[2]
	switch strings.ToLower(unit) {
	case "y":
		duration = time.Duration(amount) * 365 * 24 * time.Hour
	case "mo":
		duration = time.Duration(amount) * 30 * 24 * time.Hour
	case "d":
		duration = time.Duration(amount) * 24 * time.Hour
	case "h":
		duration = time.Duration(amount) * time.Hour
	case "m":
		duration = time.Duration(amount) * time.Minute
	case "s":
		duration = time.Duration(amount) * time.Second
	default:
		return []*model.Message{
			{
				Text:    "Invalid duration unit. Please use y (years), mo (months), d (days), h (hours), m (minutes), or s (seconds).",
				Chat:    msg.Chat,
				Channel: msg.Channel,
				Author:  "bot",
				FromBot: true,
				Date:    time.Now(),
				ReplyTo: msg.ID,
			},
		}
	}

	triggerAt := time.Now().Add(duration)

	// Determine the username for the reminder
	username := msg.Author
	if username == "" {
		// Try to extract username from message raw data
		if authorData, ok := msg.Raw["author"].(map[string]interface{}); ok {
			if name, ok := authorData["username"].(string); ok {
				username = name
			} else if name, ok := authorData["name"].(string); ok {
				username = name
			}
		}
	}

	// Create the reminder
	_, err = r.creator.CreateReminder(
		msg.Channel.Platform,
		msg.Chat,
		msg.ID,
		msg.ReplyTo,
		msg.Author,
		username,
		"", // No additional content for now
		triggerAt,
	)

	if err != nil {
		return []*model.Message{
			{
				Text:    fmt.Sprintf("Failed to create reminder: %v", err),
				Chat:    msg.Chat,
				Channel: msg.Channel,
				Author:  "bot",
				FromBot: true,
				Date:    time.Now(),
				ReplyTo: msg.ID,
			},
		}
	}

	// Format the acknowledgment message
	var confirmText string
	switch strings.ToLower(unit) {
	case "y":
		confirmText = fmt.Sprintf("I'll remind you about this message in %d year(s) on %s", amount, triggerAt.Format("Mon, Jan 2, 2006 at 15:04"))
	case "mo":
		confirmText = fmt.Sprintf("I'll remind you about this message in %d month(s) on %s", amount, triggerAt.Format("Mon, Jan 2 at 15:04"))
	case "d":
		confirmText = fmt.Sprintf("I'll remind you about this message in %d day(s) on %s", amount, triggerAt.Format("Mon, Jan 2 at 15:04"))
	case "h":
		confirmText = fmt.Sprintf("I'll remind you about this message in %d hour(s) at %s", amount, triggerAt.Format("15:04"))
	case "m":
		confirmText = fmt.Sprintf("I'll remind you about this message in %d minute(s) at %s", amount, triggerAt.Format("15:04"))
	case "s":
		confirmText = fmt.Sprintf("I'll remind you about this message in %d second(s)", amount)
	}

	return []*model.Message{
		{
			Text:    confirmText,
			Chat:    msg.Chat,
			Channel: msg.Channel,
			Author:  "bot",
			FromBot: true,
			Date:    time.Now(),
			ReplyTo: msg.ID,
		},
	}
}