package connectors

import (
	"bytes"
	"context"
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"
)

type WebhookConfig struct {
	Timeout       time.Duration
	MaxRetries    int
	RetryDelay    time.Duration
	DefaultSecret string
}

type WebhookConnector struct {
	cfg    WebhookConfig
	client *http.Client
}

func NewWebhookConnector(cfg WebhookConfig) *WebhookConnector {
	timeout := cfg.Timeout
	if timeout == 0 {
		timeout = 30 * time.Second
	}
	if cfg.MaxRetries == 0 {
		cfg.MaxRetries = 3
	}
	if cfg.RetryDelay == 0 {
		cfg.RetryDelay = time.Second
	}

	return &WebhookConnector{
		cfg: cfg,
		client: &http.Client{
			Timeout: timeout,
		},
	}
}

func (w *WebhookConnector) ID() string {
	return "webhook"
}

func (w *WebhookConnector) Name() string {
	return "Webhook"
}

func (w *WebhookConnector) Description() string {
	return "Send HTTP webhooks to external services"
}

func (w *WebhookConnector) GetActions() []Action {
	return []Action{
		{
			Name:        "post",
			Description: "Send POST request",
			Schema: map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"url":     map[string]interface{}{"type": "string", "description": "Webhook URL"},
					"body":    map[string]interface{}{"type": "object", "description": "Request body (JSON)"},
					"headers": map[string]interface{}{"type": "object", "description": "Custom headers"},
					"secret":  map[string]interface{}{"type": "string", "description": "HMAC secret for signing"},
				},
			},
			Required: []string{"url"},
		},
		{
			Name:        "get",
			Description: "Send GET request",
			Schema: map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"url":     map[string]interface{}{"type": "string", "description": "Request URL"},
					"params":  map[string]interface{}{"type": "object", "description": "Query parameters"},
					"headers": map[string]interface{}{"type": "object", "description": "Custom headers"},
				},
			},
			Required: []string{"url"},
		},
		{
			Name:        "put",
			Description: "Send PUT request",
			Schema: map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"url":     map[string]interface{}{"type": "string", "description": "Request URL"},
					"body":    map[string]interface{}{"type": "object", "description": "Request body (JSON)"},
					"headers": map[string]interface{}{"type": "object", "description": "Custom headers"},
				},
			},
			Required: []string{"url"},
		},
	}
}

func (w *WebhookConnector) Validate(params map[string]interface{}) error {
	urlStr, ok := params["url"].(string)
	if !ok {
		return errors.New("'url' is required")
	}

	parsed, err := url.Parse(urlStr)
	if err != nil {
		return fmt.Errorf("invalid URL: %w", err)
	}

	if parsed.Scheme != "http" && parsed.Scheme != "https" {
		return errors.New("URL must use http or https scheme")
	}

	return nil
}

func (w *WebhookConnector) Execute(ctx context.Context, action string, params map[string]interface{}) (interface{}, error) {
	switch action {
	case "post":
		return w.doRequest(ctx, "POST", params)
	case "get":
		return w.doRequest(ctx, "GET", params)
	case "put":
		return w.doRequest(ctx, "PUT", params)
	case "delete":
		return w.doRequest(ctx, "DELETE", params)
	case "patch":
		return w.doRequest(ctx, "PATCH", params)
	default:
		return nil, errors.New("unknown action: " + action)
	}
}

func (w *WebhookConnector) doRequest(ctx context.Context, method string, params map[string]interface{}) (interface{}, error) {
	urlStr := params["url"].(string)

	if method == "GET" {
		if queryParams, ok := params["params"].(map[string]interface{}); ok {
			parsedURL, _ := url.Parse(urlStr)
			q := parsedURL.Query()
			for k, v := range queryParams {
				q.Set(k, fmt.Sprintf("%v", v))
			}
			parsedURL.RawQuery = q.Encode()
			urlStr = parsedURL.String()
		}
	}

	var bodyReader io.Reader
	var bodyBytes []byte

	if body, ok := params["body"]; ok && method != "GET" {
		var err error
		bodyBytes, err = json.Marshal(body)
		if err != nil {
			return nil, fmt.Errorf("failed to marshal body: %w", err)
		}
		bodyReader = bytes.NewReader(bodyBytes)
	}

	var lastErr error
	for attempt := 0; attempt <= w.cfg.MaxRetries; attempt++ {
		if attempt > 0 {
			time.Sleep(w.cfg.RetryDelay * time.Duration(attempt))
			if bodyBytes != nil {
				bodyReader = bytes.NewReader(bodyBytes)
			}
		}

		req, err := http.NewRequestWithContext(ctx, method, urlStr, bodyReader)
		if err != nil {
			return nil, err
		}

		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("User-Agent", "GooSeek-Computer/1.0")

		if headers, ok := params["headers"].(map[string]interface{}); ok {
			for k, v := range headers {
				req.Header.Set(k, fmt.Sprintf("%v", v))
			}
		}

		if bodyBytes != nil {
			secret := w.cfg.DefaultSecret
			if s, ok := params["secret"].(string); ok {
				secret = s
			}
			if secret != "" {
				signature := w.signPayload(bodyBytes, secret)
				req.Header.Set("X-Signature-256", "sha256="+signature)
			}
		}

		resp, err := w.client.Do(req)
		if err != nil {
			lastErr = err
			continue
		}

		respBody, err := io.ReadAll(resp.Body)
		resp.Body.Close()
		if err != nil {
			lastErr = err
			continue
		}

		result := map[string]interface{}{
			"status_code": resp.StatusCode,
			"headers":     w.headersToMap(resp.Header),
		}

		var jsonBody interface{}
		if err := json.Unmarshal(respBody, &jsonBody); err == nil {
			result["body"] = jsonBody
		} else {
			result["body"] = string(respBody)
		}

		if resp.StatusCode >= 200 && resp.StatusCode < 300 {
			result["success"] = true
			return result, nil
		}

		if resp.StatusCode >= 500 {
			lastErr = fmt.Errorf("server error: %d", resp.StatusCode)
			continue
		}

		result["success"] = false
		return result, nil
	}

	return map[string]interface{}{
		"success": false,
		"error":   lastErr.Error(),
	}, lastErr
}

func (w *WebhookConnector) signPayload(payload []byte, secret string) string {
	mac := hmac.New(sha256.New, []byte(secret))
	mac.Write(payload)
	return hex.EncodeToString(mac.Sum(nil))
}

func (w *WebhookConnector) headersToMap(headers http.Header) map[string]string {
	result := make(map[string]string)
	for k, v := range headers {
		result[k] = strings.Join(v, ", ")
	}
	return result
}

func (w *WebhookConnector) PostJSON(ctx context.Context, webhookURL string, data interface{}) (interface{}, error) {
	return w.Execute(ctx, "post", map[string]interface{}{
		"url":  webhookURL,
		"body": data,
	})
}

func (w *WebhookConnector) GetJSON(ctx context.Context, webhookURL string, params map[string]interface{}) (interface{}, error) {
	return w.Execute(ctx, "get", map[string]interface{}{
		"url":    webhookURL,
		"params": params,
	})
}