package main

import (
    "fmt"
    "log"
    "math/rand"
    "net/http"
    "net/url"
    "strconv"
	"strings"
    "time"
    "html/template"
    "github.com/PuerkitoBio/goquery"
)

// Define a struct to represent search result
type SearchResult struct {
    URL         string
    Header      string
    Description string
}

var funcs = template.FuncMap{
    "title": func(s string) string {
        return strings.Title(s)
    },
    "url_for": func(filename string) string {
        return "/" + filename
    },
}

var templates = template.Must(template.New("").Funcs(funcs).ParseFiles("templates/results.html"))

func main() {
    // Serve static files from the 'static' directory
    http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))

    http.HandleFunc("/", handleSearch)
    http.HandleFunc("/search", handleSearch)
    fmt.Println("Server is listening on http://localhost:5000")
    log.Fatal(http.ListenAndServe(":5000", nil))
}

func handleSearch(w http.ResponseWriter, r *http.Request) {
    var query, safe, lang string

    // Differentiate between GET and POST requests to correctly extract query, safe, and lang.
    if r.Method == "GET" {
        // Serve the search page if no query is provided for a GET request
        // Or extract the query parameters directly from the URL if present
        query = r.URL.Query().Get("q")
        if query == "" {
            http.ServeFile(w, r, "static/search.html")
            return
        }
        safe = r.URL.Query().Get("safe")
        lang = r.URL.Query().Get("lang")
    } else if r.Method == "POST" {
        // For a POST request, extract form values
        query = r.FormValue("q")
        safe = r.FormValue("safe")
        lang = r.FormValue("lang")
    }

    // Early return if query is empty
    if query == "" {
        http.ServeFile(w, r, "static/search.html")
        return
    }

    // Time
    start := time.Now()

    // Adjust the search URL based on safe search and language settings
    var safeParam string
    if safe == "active" {
        safeParam = "&safe=active"
    } else {
        safeParam = "&safe=off"
    }

    var langParam string
    if lang != "" {
        langParam = "&lr=" + lang
    }

    searchURL := "https://www.google.com/search?q=" + url.QueryEscape(query) + safeParam + langParam
    print(searchURL+"\n")
    req, err := http.NewRequest("GET", searchURL, nil)
    if err != nil {
        http.Error(w, "Failed to create request", http.StatusInternalServerError)
        return
    }

    // Random user agent
    userAgents := []string{
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36",
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36",
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:107.0) Gecko/20100101 Firefox/107.0",
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36",
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:106.0) Gecko/20100101 Firefox/106.0",
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.1 Safari/605.1.15",
    }
    randIndex := rand.Intn(len(userAgents))
    userAgent := userAgents[randIndex]

    req.Header.Set("User-Agent", userAgent)
    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        http.Error(w, "Failed to fetch search results", http.StatusInternalServerError)
        return
    }
    defer resp.Body.Close()

    // Parse HTML
    doc, err := goquery.NewDocumentFromReader(resp.Body)
    if err != nil {
        http.Error(w, "Failed to parse HTML", http.StatusInternalServerError)
        return
    }

    // Retrieve links, headers, and descriptions
    var results []SearchResult
    doc.Find(".yuRUbf").Each(func(i int, s *goquery.Selection) {
        link := s.Find("a")
        href, _ := link.Attr("href")
        header := link.Find("h3").Text()
        header = strings.TrimSpace(strings.TrimSuffix(header, "›"))

        descSelection := doc.Find(".VwiC3b").Eq(i)
        description := ""
        if descSelection.Length() > 0 {
            description = descSelection.Text()
        }

        results = append(results, SearchResult{
            URL:         href,
            Header:      header,
            Description: description,
        })
    })

    elapsed := time.Since(start)

    // Prepare data for rendering template
    data := struct {
        Results     []SearchResult
        Query       string
        Fetched     string
        ElapsedTime string
    }{
        Results:     results,
        Query:       query,
        Fetched:     fmt.Sprintf("Fetched the results in %.2f seconds", elapsed.Seconds()),
        ElapsedTime: strconv.FormatFloat(elapsed.Seconds(), 'f', 2, 64),
    }

    // Render template
    err = templates.ExecuteTemplate(w, "results.html", data)
    if err != nil {
        http.Error(w, "Failed to render template", http.StatusInternalServerError)
        return
    }
}