Initial commit: Telegram voice/video transcription bot in Zig

Long-polling bot that accepts voice messages and video notes,
sends them to Whisper STT API, and replies with transcription text.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/http.zig

@@ -0,0 +1,104 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+
+pub fn httpGet(allocator: Allocator, url: []const u8) ![]u8 {
+    var client: std.http.Client = .{ .allocator = allocator };
+    defer client.deinit();
+
+    var aw: std.Io.Writer.Allocating = .init(allocator);
+    defer aw.deinit();
+
+    const result = client.fetch(.{
+        .location = .{ .url = url },
+        .response_writer = &aw.writer,
+    }) catch return error.HttpRequestFailed;
+
+    if (result.status != .ok) return error.HttpRequestFailed;
+
+    return aw.toOwnedSlice() catch return error.OutOfMemory;
+}
+
+pub fn httpPostJson(allocator: Allocator, url: []const u8, body: []const u8) ![]u8 {
+    var client: std.http.Client = .{ .allocator = allocator };
+    defer client.deinit();
+
+    var aw: std.Io.Writer.Allocating = .init(allocator);
+    defer aw.deinit();
+
+    const result = client.fetch(.{
+        .location = .{ .url = url },
+        .method = .POST,
+        .payload = body,
+        .headers = .{ .content_type = .{ .override = "application/json" } },
+        .response_writer = &aw.writer,
+    }) catch return error.HttpRequestFailed;
+
+    if (result.status != .ok) return error.HttpRequestFailed;
+
+    return aw.toOwnedSlice() catch return error.OutOfMemory;
+}
+
+pub fn httpPostMultipart(
+    allocator: Allocator,
+    url: []const u8,
+    file_field: []const u8,
+    file_path: []const u8,
+    file_name: []const u8,
+    fields: []const [2][]const u8,
+) ![]u8 {
+    const boundary = "----ZigMultipartBoundary9876543210";
+
+    // Build multipart body
+    var body_writer: std.Io.Writer.Allocating = .init(allocator);
+    defer body_writer.deinit();
+
+    // Add form fields
+    for (fields) |field| {
+        body_writer.writer.print("--{s}\r\nContent-Disposition: form-data; name=\"{s}\"\r\n\r\n{s}\r\n", .{ boundary, field[0], field[1] }) catch return error.OutOfMemory;
+    }
+
+    // Add file field header
+    body_writer.writer.print("--{s}\r\nContent-Disposition: form-data; name=\"{s}\"; filename=\"{s}\"\r\nContent-Type: application/octet-stream\r\n\r\n", .{ boundary, file_field, file_name }) catch return error.OutOfMemory;
+
+    // Read and append file content
+    const file = std.fs.openFileAbsolute(file_path, .{}) catch return error.HttpRequestFailed;
+    defer file.close();
+    const file_content = file.readToEndAlloc(allocator, 100 * 1024 * 1024) catch return error.HttpRequestFailed;
+    defer allocator.free(file_content);
+
+    body_writer.writer.writeAll(file_content) catch return error.OutOfMemory;
+    body_writer.writer.print("\r\n--{s}--\r\n", .{boundary}) catch return error.OutOfMemory;
+
+    const body = body_writer.written();
+
+    // Send request
+    var client: std.http.Client = .{ .allocator = allocator };
+    defer client.deinit();
+
+    var response_aw: std.Io.Writer.Allocating = .init(allocator);
+    defer response_aw.deinit();
+
+    const content_type = std.fmt.allocPrint(allocator, "multipart/form-data; boundary={s}", .{boundary}) catch return error.OutOfMemory;
+    defer allocator.free(content_type);
+
+    const result = client.fetch(.{
+        .location = .{ .url = url },
+        .method = .POST,
+        .payload = body,
+        .headers = .{ .content_type = .{ .override = content_type } },
+        .response_writer = &response_aw.writer,
+    }) catch return error.HttpRequestFailed;
+
+    if (result.status != .ok) return error.HttpRequestFailed;
+
+    return response_aw.toOwnedSlice() catch return error.OutOfMemory;
+}
+
+pub fn downloadToFile(allocator: Allocator, url: []const u8, dest_path: []const u8) !void {
+    const data = try httpGet(allocator, url);
+    defer allocator.free(data);
+
+    const file = std.fs.createFileAbsolute(dest_path, .{}) catch return error.HttpRequestFailed;
+    defer file.close();
+    file.writeAll(data) catch return error.HttpRequestFailed;
+}