From cc0dc64d91568bd65da920fc415f2555ba3ca0f5 Mon Sep 17 00:00:00 2001
From: Leonid Nikitin <i@kor-elf.net>
Date: Sat, 14 Mar 2026 11:36:04 +0500
Subject: [PATCH] Add blocklist package with config and data fetching functions

---
 blocklist.go | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 blocklist.go

diff --git a/blocklist.go b/blocklist.go
new file mode 100644
index 0000000..06a2e7b
--- /dev/null
+++ b/blocklist.go
@@ -0,0 +1,93 @@
+package blocklist
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"time"
+
+	"git.kor-elf.net/kor-elf-shield/blocklist/parser"
+)
+
+const (
+
+	// contextTimeout defines the maximum duration for context operations before timing out.
+	contextTimeout = 15 * time.Second
+	// requestTimeout defines the maximum duration for request operations before timing out.
+	requestTimeout = 20 * time.Second
+)
+
+// Config defines the configuration for the blocklist.
+type Config struct {
+
+	// Limit specifies the maximum number of items to process or validate.
+	Limit uint
+
+	// Validator specifies the IP validator to use.
+	Validator parser.IPValidator
+
+	// ContextTimeout defines the maximum duration for context operations before timing out.
+	ContextTimeout time.Duration
+
+	// RequestTimeout defines the maximum duration for request operations before timing out.
+	RequestTimeout time.Duration
+}
+
+// NewConfig creates a new Config with default values.
+func NewConfig(limit uint) Config {
+	return Config{
+		Limit:          limit,
+		Validator:      &parser.DefaultIPValidator{},
+		ContextTimeout: contextTimeout,
+		RequestTimeout: requestTimeout,
+	}
+}
+
+// NewConfigWithValidator creates a new Config with the specified validator.
+func NewConfigWithValidator(limit uint, validator parser.IPValidator) Config {
+	return Config{
+		Limit:          limit,
+		Validator:      validator,
+		ContextTimeout: contextTimeout,
+		RequestTimeout: requestTimeout,
+	}
+}
+
+// Get fetches data from the given URL, parses the response using the provided parser, and applies the given configuration.
+// It returns the parsed IPs and any errors that occurred during the process.
+func Get(fileUrl string, parser parser.Parser, c Config) (parser.IPs, error) {
+	parsedURL, err := url.Parse(fileUrl)
+	if err != nil {
+		return nil, fmt.Errorf("invalid url: %w", err)
+	}
+	if parsedURL.Scheme != "http" && parsedURL.Scheme != "https" {
+		return nil, fmt.Errorf("invalid url scheme: %s", parsedURL.Scheme)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), c.ContextTimeout)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, fileUrl, nil)
+	if err != nil {
+		return nil, fmt.Errorf("create request: %w", err)
+	}
+
+	client := &http.Client{
+		Timeout: c.RequestTimeout,
+	}
+
+	res, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("request failed: %w", err)
+	}
+	defer func() {
+		_ = res.Body.Close()
+	}()
+
+	if res.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("unexpected status code: %d", res.StatusCode)
+	}
+
+	return parser.Parse(res.Body, c.Validator, c.Limit)
+}