package dns

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"time"
)

type Client struct {
	baseURL    string
	token      string
	username   string
	password   string
	httpClient *http.Client
}

type AddRecordRequest struct {
	Domain    string `json:"domain"`
	Type      string `json:"type"`
	IPAddress string `json:"ipAddress,omitempty"`
	Overwrite bool   `json:"overwrite"`
	TTL       int    `json:"ttl,omitempty"`
}

type AddRecordResponse struct {
	Status    string `json:"status"`
	ErrorCode string `json:"errorCode,omitempty"`
	Error     string `json:"errorMessage,omitempty"`
}

type APIResponse struct {
	Status   string          `json:"status"`
	Response json.RawMessage `json:"response"`
	Error    *APIError       `json:"error,omitempty"`
}

type APIError struct {
	Code    string `json:"code"`
	Message string `json:"message"`
}

func NewClient(baseURL, token, username, password string) *Client {
	return &Client{
		baseURL:  baseURL,
		token:    token,
		username: username,
		password: password,
		httpClient: &http.Client{
			Timeout: 30 * time.Second,
		},
	}
}

func (c *Client) AddARecord(zone, hostname, ip string, ttl int) error {
	domain := fmt.Sprintf("%s.%s", hostname, zone)

	reqBody := AddRecordRequest{
		Domain:    domain,
		Type:      "A",
		IPAddress: ip,
		Overwrite: true,
	}

	if ttl > 0 {
		reqBody.TTL = ttl
	}

	return c.addRecord(reqBody)
}

func (c *Client) AddWildcardARecord(zone, hostname, ip string, ttl int) error {
	domain := fmt.Sprintf("*.%s.%s", hostname, zone)

	reqBody := AddRecordRequest{
		Domain:    domain,
		Type:      "A",
		IPAddress: ip,
		Overwrite: true,
	}

	if ttl > 0 {
		reqBody.TTL = ttl
	}

	return c.addRecord(reqBody)
}

func (c *Client) addRecord(req AddRecordRequest) error {
	endpoint := fmt.Sprintf("%s/api/dns/records/add", c.baseURL)

	formData := url.Values{}
	formData.Set("domain", req.Domain)
	formData.Set("type", req.Type)
	formData.Set("ipAddress", req.IPAddress)
	formData.Set("overwrite", fmt.Sprintf("%t", req.Overwrite))
	if req.TTL > 0 {
		formData.Set("ttl", fmt.Sprintf("%d", req.TTL))
	}

	httpReq, err := http.NewRequest("POST", endpoint, bytes.NewBufferString(formData.Encode()))
	if err != nil {
		return fmt.Errorf("failed to create request: %w", err)
	}

	httpReq.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	if c.token != "" {
		httpReq.Header.Set("Authorization", "Basic "+c.token)
	} else if c.username != "" && c.password != "" {
		httpReq.SetBasicAuth(c.username, c.password)
	}

	resp, err := c.httpClient.Do(httpReq)
	if err != nil {
		return fmt.Errorf("failed to execute request: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return fmt.Errorf("failed to read response body: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("HTTP error %d: %s", resp.StatusCode, string(body))
	}

	var apiResp APIResponse
	if err := json.Unmarshal(body, &apiResp); err != nil {
		return fmt.Errorf("failed to parse response: %w", err)
	}

	if apiResp.Status != "ok" {
		if apiResp.Error != nil {
			return fmt.Errorf("API error: %s - %s", apiResp.Error.Code, apiResp.Error.Message)
		}
		return fmt.Errorf("API error: status not ok")
	}

	return nil
}

func (c *Client) DeleteRecord(zone, hostname, recordType string) error {
	endpoint := fmt.Sprintf("%s/api/dns/records/delete", c.baseURL)

	domain := fmt.Sprintf("%s.%s", hostname, zone)
	if hostname == "" || hostname == "@" {
		domain = zone
	}

	formData := url.Values{}
	formData.Set("domain", domain)
	formData.Set("type", recordType)

	httpReq, err := http.NewRequest("POST", endpoint, bytes.NewBufferString(formData.Encode()))
	if err != nil {
		return fmt.Errorf("failed to create request: %w", err)
	}

	httpReq.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	if c.token != "" {
		httpReq.Header.Set("Authorization", "Basic "+c.token)
	} else if c.username != "" && c.password != "" {
		httpReq.SetBasicAuth(c.username, c.password)
	}

	resp, err := c.httpClient.Do(httpReq)
	if err != nil {
		return fmt.Errorf("failed to execute request: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("HTTP error %d: %s", resp.StatusCode, string(body))
	}

	return nil
}