Feat/Flaresolverr support (#12)

* new: feat: add flaresolverr support

* chg: feat: add session pool

* chg: fix: deadlock error

* chg: fix: make it work without flaresolverr

requester/flaresolverr.go

@@ -0,0 +1,230 @@
+package requester
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"sync"
+)
+
+type FlareSolverr struct {
+	url         string
+	maxTimeout  int
+	httpClient  *http.Client
+	sessionPool chan string
+	mu          sync.Mutex
+	initiated   bool
+}
+
+func NewFlareSolverr(url string, timeoutMilli int) *FlareSolverr {
+	poolSize := 5
+	httpClient := &http.Client{}
+	sessionPool := make(chan string, poolSize) // Pool size of 5 sessions
+
+	f := &FlareSolverr{
+		url:         url,
+		maxTimeout:  timeoutMilli,
+		httpClient:  httpClient,
+		sessionPool: sessionPool,
+	}
+
+	err := f.FillSessionPool()
+	if err == nil {
+		f.initiated = true
+	}
+
+	return f
+}
+
+func (f *FlareSolverr) FillSessionPool() error {
+	// Check if the pool is already filled
+	if len(f.sessionPool) == cap(f.sessionPool) {
+		return nil
+	}
+
+	// Pre-initialize the pool with existing sessions
+	sessions, err := f.ListSessions()
+	if err != nil {
+		fmt.Println("Failed to list existing FlareSolverr sessions:", err)
+		return err
+	} else {
+		for _, session := range sessions {
+			// Add available sessions to the pool
+			if len(f.sessionPool) < cap(f.sessionPool) {
+				f.sessionPool <- session
+			}
+		}
+		if len(f.sessionPool) > 0 {
+			fmt.Printf("Added %d FlareSolverr sessions to the pool\n", len(f.sessionPool))
+		}
+	}
+
+	// If fewer than poolSize sessions were found, create new ones to fill the pool
+	for len(f.sessionPool) < cap(f.sessionPool) {
+		f.CreateSession()
+	}
+
+	return nil
+}
+
+func (f *FlareSolverr) CreateSession() string {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	body := map[string]string{"cmd": "sessions.create"}
+	jsonBody, err := json.Marshal(body)
+	if err != nil {
+		return ""
+	}
+
+	req, err := http.NewRequest("POST", fmt.Sprintf("%s/v1", f.url), bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return ""
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := f.httpClient.Do(req)
+	if err != nil {
+		return ""
+	}
+
+	defer resp.Body.Close()
+
+	var sessionResponse map[string]interface{}
+	err = json.NewDecoder(resp.Body).Decode(&sessionResponse)
+	if err != nil {
+		return ""
+	}
+
+	session := sessionResponse["session"].(string)
+	// Add session to the pool
+	f.sessionPool <- session
+
+	fmt.Println("Created new FlareSolverr session:", session)
+	return session
+}
+
+func (f *FlareSolverr) ListSessions() ([]string, error) {
+	body := map[string]string{"cmd": "sessions.list"}
+	jsonBody, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("POST", fmt.Sprintf("%s/v1", f.url), bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := f.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer resp.Body.Close()
+
+	var sessionsResponse map[string]interface{}
+	err = json.NewDecoder(resp.Body).Decode(&sessionsResponse)
+	if err != nil {
+		return nil, err
+	}
+
+	sessions := sessionsResponse["sessions"].([]interface{})
+	var sessionIDs []string
+	for _, session := range sessions {
+		sessionIDs = append(sessionIDs, session.(string))
+	}
+
+	return sessionIDs, nil
+}
+
+func (f *FlareSolverr) RetrieveSession() string {
+	// Blocking receive from the session pool.
+	session := <-f.sessionPool
+	return session
+}
+
+type Response struct {
+	Status   string `json:"status"`
+	Message  string `json:"message"`
+	Solution struct {
+		Url     string `json:"url"`
+		Status  int    `json:"status"`
+		Cookies []struct {
+			Domain   string `json:"domain"`
+			Expiry   int    `json:"expiry"`
+			HttpOnly bool   `json:"httpOnly"`
+			Name     string `json:"name"`
+			Path     string `json:"path"`
+			SameSite string `json:"sameSite"`
+			Secure   bool   `json:"secure"`
+			Value    string `json:"value"`
+		} `json:"cookies"`
+		UserAgent string            `json:"userAgent"`
+		Headers   map[string]string `json:"headers"`
+		Response  string            `json:"response"`
+	} `json:"solution"`
+}
+
+func (f *FlareSolverr) Get(url string) (io.ReadCloser, error) {
+	// Check if the FlareSolverr instance was initiated
+	if !f.initiated {
+		return io.NopCloser(bytes.NewReader([]byte(""))), nil
+	}
+
+	// Retrieve session from the pool (blocking if no sessions available)
+	session := f.RetrieveSession()
+
+	// Ensure the session is returned to the pool after the request is done
+	defer func() {
+		f.sessionPool <- session
+	}()
+
+	body := map[string]string{
+		"cmd":        "request.get",
+		"url":        url,
+		"maxTimeout": fmt.Sprintf("%d", f.maxTimeout),
+		"session":    session,
+	}
+	jsonBody, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequest("POST", fmt.Sprintf("%s/v1", f.url), bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := f.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// Parse the response
+	var response Response
+	err = json.NewDecoder(resp.Body).Decode(&response)
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if the response was successful
+	if response.Status != "ok" {
+		return nil, fmt.Errorf("failed to get response: %s", response.Message)
+	}
+
+	// Check if "Under attack" is in the response
+	if strings.Contains(response.Solution.Response, "Under attack") {
+		return nil, fmt.Errorf("under attack")
+	}
+
+	// Return the response body
+	return io.NopCloser(bytes.NewReader([]byte(response.Solution.Response))), nil
+}