package client

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"git.db.org.ai/dborg/internal/models"
	"io"
	"net/http"
	"net/url"
	"strings"
)

func parseSSEResponse(data []byte) ([]byte, error) {
	scanner := bufio.NewScanner(bytes.NewReader(data))

	const maxScanTokenSize = 10 * 1024 * 1024
	buf := make([]byte, maxScanTokenSize)
	scanner.Buffer(buf, maxScanTokenSize)

	var resultData []byte
	var foundResult bool

	for scanner.Scan() {
		line := scanner.Text()

		if line == "event: result" {
			foundResult = true
			continue
		}

		if foundResult && strings.HasPrefix(line, "data: ") {
			resultData = []byte(strings.TrimPrefix(line, "data: "))
			break
		}
	}

	if err := scanner.Err(); err != nil {
		return nil, fmt.Errorf("error reading SSE response: %w", err)
	}

	if resultData == nil {
		return nil, fmt.Errorf("no result event found in SSE response")
	}

	trimmed := strings.TrimSpace(string(resultData))
	if !strings.HasPrefix(trimmed, "{") && !strings.HasPrefix(trimmed, "[") {
		return nil, fmt.Errorf("API returned: %s", trimmed)
	}

	return resultData, nil
}

func (c *Client) getSSE(path string, params url.Values) ([]byte, error) {
	fullURL := c.config.BaseURL + path
	if params != nil && len(params) > 0 {
		fullURL += "?" + params.Encode()
	}

	req, err := http.NewRequest("GET", fullURL, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("X-API-Key", c.config.APIKey)
	req.Header.Set("User-Agent", c.config.UserAgent)

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

	if resp.StatusCode != http.StatusOK {
		bodyBytes, _ := io.ReadAll(resp.Body)
		switch resp.StatusCode {
		case http.StatusPaymentRequired:
			return nil, fmt.Errorf("insufficient credits (402): %s - Please add credits to your account", string(bodyBytes))
		case http.StatusForbidden:
			return nil, fmt.Errorf("access denied (403): %s - This endpoint requires premium access", string(bodyBytes))
		case http.StatusUnauthorized:
			return nil, fmt.Errorf("unauthorized (401): %s - Check your API key", string(bodyBytes))
		case http.StatusTooManyRequests:
			return nil, fmt.Errorf("rate limit exceeded (429): %s", string(bodyBytes))
		case http.StatusBadRequest:
			return nil, fmt.Errorf("bad request (400): %s", string(bodyBytes))
		default:
			return nil, fmt.Errorf("API request failed with status %d: %s", resp.StatusCode, string(bodyBytes))
		}
	}

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

	contentType := resp.Header.Get("Content-Type")

	if strings.HasPrefix(string(data), "event:") || strings.Contains(contentType, "text/event-stream") {
		return parseSSEResponse(data)
	}

	return data, nil
}

func (c *Client) SearchPeople(params *models.SkiptraceParams) (*models.SkiptraceResponse, error) {
	queryParams := url.Values{}
	queryParams.Set("first_name", params.FirstName)
	queryParams.Set("last_name", params.LastName)

	if params.City != "" {
		queryParams.Set("city", params.City)
	}
	if params.State != "" {
		queryParams.Set("state", params.State)
	}
	if params.Age != "" {
		queryParams.Set("age", params.Age)
	}

	data, err := c.getSSE("/prem/skiptrace/people/search", queryParams)
	if err != nil {
		return nil, err
	}

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

	return &response, nil
}

func (c *Client) GetPersonReport(sxKey string, selection int) (*models.SkiptraceReportResponse, error) {
	path := fmt.Sprintf("/prem/skiptrace/people/report/%s/%d", sxKey, selection)

	data, err := c.getSSE(path, nil)
	if err != nil {
		return nil, err
	}

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

	return &response, nil
}

func (c *Client) SearchPhone(phone string) (*models.SkiptracePhoneResponse, error) {
	path := fmt.Sprintf("/prem/skiptrace/phone/%s", phone)

	data, err := c.getSSE(path, nil)
	if err != nil {
		return nil, err
	}

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

	return &response, nil
}

func (c *Client) SearchEmail(email string) (*models.SkiptraceEmailResponse, error) {
	path := fmt.Sprintf("/prem/skiptrace/email/%s", email)

	data, err := c.getSSE(path, nil)
	if err != nil {
		return nil, err
	}

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

	return &response, nil
}