package google

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"time"

	"git.linuxforward.com/byom/byom-trends/config"
	"git.linuxforward.com/byom/byom-trends/logger"
	"github.com/sirupsen/logrus"
)

type Client struct {
	httpClient *http.Client
	apiKey     string
	baseURL    string
	logger     *logrus.Entry
}

type TrendResult struct {
	Keyword          string          `json:"keyword"`
	TimeRange        string          `json:"time_range"`
	Interest         []InterestPoint `json:"interest"`
	RelatedTopics    []RelatedTopic  `json:"related_topics"`
	RegionalInterest map[string]int  `json:"regional_interest"`
}

type InterestPoint struct {
	Date  time.Time `json:"date"`
	Value int       `json:"value"`
}

type RelatedTopic struct {
	Title string `json:"title"`
	Type  string `json:"type"`
	Value int    `json:"value"`
}

func NewClient(cfg *config.GoogleConfig) *Client {
	return &Client{
		httpClient: &http.Client{
			Timeout: time.Second * 10,
		},
		apiKey:  cfg.TrendsAPIKey,
		baseURL: cfg.BaseURL,
		logger:  logger.NewLogger("google-trends-client"),
	}
}

func (c *Client) GetTrends(keyword string, timeRange string) (*TrendResult, error) {
	params := url.Values{}
	params.Add("keyword", keyword)
	params.Add("time_range", timeRange)
	params.Add("key", c.apiKey)

	url := fmt.Sprintf("%s/dailytrends?%s", c.baseURL, params.Encode())

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

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

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
	}

	var result TrendResult
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return nil, fmt.Errorf("decode response: %w", err)
	}

	return &result, nil
}

func (c *Client) CompareKeywords(keywords []string, timeRange string) (map[string]*TrendResult, error) {
	results := make(map[string]*TrendResult)

	for _, keyword := range keywords {
		result, err := c.GetTrends(keyword, timeRange)
		if err != nil {
			return nil, fmt.Errorf("get trends for %s: %w", keyword, err)
		}
		results[keyword] = result
	}

	return results, nil
}

func (c *Client) GetRelatedTopics(keyword string) ([]RelatedTopic, error) {
	params := url.Values{}
	params.Add("keyword", keyword)
	params.Add("key", c.apiKey)

	url := fmt.Sprintf("%s/relatedTopics?%s", c.baseURL, params.Encode())

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

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

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
	}

	var topics []RelatedTopic
	if err := json.NewDecoder(resp.Body).Decode(&topics); err != nil {
		return nil, fmt.Errorf("decode response: %w", err)
	}

	return topics, nil
}

func (c *Client) GetRegionalInterest(keyword string, region string) (map[string]int, error) {
	params := url.Values{}
	params.Add("keyword", keyword)
	params.Add("region", region)
	params.Add("key", c.apiKey)

	url := fmt.Sprintf("%s/regionalInterest?%s", c.baseURL, params.Encode())

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

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

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
	}

	var interest map[string]int
	if err := json.NewDecoder(resp.Body).Decode(&interest); err != nil {
		return nil, fmt.Errorf("decode response: %w", err)
	}

	return interest, nil
}