package slack

import (
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"strings"
	"time"

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

// SlackPlatform implements the Platform interface for Slack
type SlackPlatform struct {
	config *config.SlackConfig
}

// New creates a new SlackPlatform instance
func New(cfg *config.SlackConfig) *SlackPlatform {
	return &SlackPlatform{
		config: cfg,
	}
}

// Init initializes the Slack platform
func (s *SlackPlatform) Init(_ *config.Config) error {
	// Validate config
	if s.config.Token == "" || s.config.BotOAuthAccessToken == "" {
		return model.ErrPlatformInit
	}
	return nil
}

// ParseIncomingMessage parses an incoming Slack message
func (s *SlackPlatform) ParseIncomingMessage(r *http.Request) (*model.Message, error) {
	// Read request body
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		return nil, err
	}
	defer r.Body.Close()

	// Parse JSON
	var requestData map[string]interface{}
	if err := json.Unmarshal(body, &requestData); err != nil {
		return nil, err
	}

	// Verify Slack request
	// This is a simplified version, production should include signature verification
	urlVerify, ok := requestData["type"]
	if ok && urlVerify == "url_verification" {
		return nil, errors.New("url verification") // Handle separately
	}

	// Process event
	event, ok := requestData["event"].(map[string]interface{})
	if !ok {
		return nil, errors.New("invalid event")
	}

	// Create message
	msg := &model.Message{
		Raw: requestData,
	}

	// Get text
	if text, ok := event["text"].(string); ok {
		msg.Text = text
	}

	// Get channel
	if channel, ok := event["channel"].(string); ok {
		msg.Chat = channel

		// Create Channel object
		channelRaw, err := s.ParseChannelFromMessage(body)
		if err != nil {
			return nil, err
		}

		msg.Channel = &model.Channel{
			Platform:          "slack",
			PlatformChannelID: channel,
			ChannelRaw:        channelRaw,
		}
	}

	// Check if from bot
	if botID, ok := event["bot_id"].(string); ok && botID != "" {
		msg.FromBot = true
	}

	// Get user
	if user, ok := event["user"].(string); ok {
		msg.Author = user
	}

	// Get timestamp
	if ts, ok := event["ts"].(string); ok {
		// Convert Unix timestamp
		parts := strings.Split(ts, ".")
		if len(parts) > 0 {
			if sec, err := parseInt64(parts[0]); err == nil {
				msg.Date = time.Unix(sec, 0)
				msg.ID = ts
			}
		}
	}

	return msg, nil
}

// ParseChannelNameFromRaw extracts a human-readable channel name from raw data
func (s *SlackPlatform) ParseChannelNameFromRaw(channelRaw map[string]interface{}) string {
	// Extract name from channel raw data
	if name, ok := channelRaw["name"].(string); ok {
		return name
	}

	// Fallback to ID if available
	if id, ok := channelRaw["id"].(string); ok {
		return id
	}

	return "unknown"
}

// ParseChannelFromMessage extracts channel data from a message
func (s *SlackPlatform) ParseChannelFromMessage(body []byte) (map[string]any, error) {
	// Parse JSON
	var requestData map[string]interface{}
	if err := json.Unmarshal(body, &requestData); err != nil {
		return nil, err
	}

	// Extract channel info from event
	event, ok := requestData["event"].(map[string]interface{})
	if !ok {
		return nil, errors.New("invalid event data")
	}

	channelID, ok := event["channel"].(string)
	if !ok {
		return nil, errors.New("channel ID not found")
	}

	// In a real implementation, you might want to fetch more details about the channel
	// using the Slack API, but for simplicity we'll just return the ID
	channelRaw := map[string]interface{}{
		"id": channelID,
	}

	return channelRaw, nil
}

// SendMessage sends a message to Slack
func (s *SlackPlatform) SendMessage(msg *model.Message) error {
	if s.config.BotOAuthAccessToken == "" {
		return errors.New("bot token not configured")
	}

	// Prepare payload
	payload := map[string]interface{}{
		"channel": msg.Chat,
		"text":    msg.Text,
	}

	// Add thread_ts if it's a reply
	if msg.ReplyTo != "" {
		payload["thread_ts"] = msg.ReplyTo
	}

	// Convert payload to JSON
	data, err := json.Marshal(payload)
	if err != nil {
		return err
	}

	// Send HTTP request
	req, err := http.NewRequest("POST", "https://slack.com/api/chat.postMessage", strings.NewReader(string(data)))
	if err != nil {
		return err
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", s.config.BotOAuthAccessToken))

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	// Check response
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("slack API error: %d", resp.StatusCode)
	}

	return nil
}

// Helper function to parse int64
func parseInt64(s string) (int64, error) {
	var n int64
	_, err := fmt.Sscanf(s, "%d", &n)
	return n, err
}