From 21f3efe78ecfdbeef81e4ba525e94233efaa9e29 Mon Sep 17 00:00:00 2001
From: iddev5 <ayushbardhan5@gmail.com>
Date: Thu, 14 Jul 2022 13:20:23 +0530
Subject: [PATCH] sysaudio: webaudio: Add intitial implementation and
 boilerplate

---
 sysaudio/src/main.zig     |  2 +-
 sysaudio/src/webaudio.zig | 88 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 89 insertions(+), 1 deletion(-)
 create mode 100644 sysaudio/src/webaudio.zig

diff --git a/sysaudio/src/main.zig b/sysaudio/src/main.zig
index cdd03821..77d1e91a 100644
--- a/sysaudio/src/main.zig
+++ b/sysaudio/src/main.zig
@@ -2,7 +2,7 @@ const std = @import("std");
 const mem = std.mem;
 const testing = std.testing;
 const builtin = @import("builtin");
-const Backend = switch (builtin.os.tag) {
+const Backend = if (builtin.cpu.arch == .wasm32) @import("webaudio.zig") else switch (builtin.os.tag) {
     .linux,
     .windows,
     .macos,
diff --git a/sysaudio/src/webaudio.zig b/sysaudio/src/webaudio.zig
new file mode 100644
index 00000000..024f1668
--- /dev/null
+++ b/sysaudio/src/webaudio.zig
@@ -0,0 +1,88 @@
+const std = @import("std");
+const Mode = @import("main.zig").Mode;
+const DeviceDescriptor = @import("main.zig").DeviceDescriptor;
+const js = @import("sysjs");
+
+const Audio = @This();
+
+pub const Device = struct {
+    context: js.Object,
+
+    pub fn deinit(device: Device) void {
+        device.context.deinit();
+    }
+};
+
+pub const DeviceIterator = struct {
+    ctx: *Audio,
+    mode: Mode,
+
+    pub fn next(_: DeviceIterator) IteratorError!?DeviceDescriptor {
+        return null;
+    }
+};
+
+pub const IteratorError = error{};
+
+pub const Error = error{
+    AudioUnsupported,
+};
+
+context_constructor: js.Function,
+
+pub fn init() Error!Audio {
+    const context = js.global().get("AudioContext");
+    if (context.is(.undef))
+        return error.AudioUnsupported;
+
+    return Audio{ .context_constructor = context.view(.func) };
+}
+
+pub fn deinit(audio: Audio) void {
+    audio.context_constructor.deinit();
+}
+
+pub fn waitEvents(_: Audio) void {}
+
+pub fn requestDevice(audio: Audio, config: DeviceDescriptor) Error!Device {
+    const context = audio.context_constructor.construct(&.{});
+    _ = context.call("suspend", &.{});
+
+    const input_channels = if (config.mode.? == .input) js.createNumber(@intToFloat(f64, config.channels.?)) else js.createUndefined();
+    const output_channels = if (config.mode.? == .output) js.createNumber(@intToFloat(f64, config.channels.?)) else js.createUndefined();
+
+    const node = context.call("createScriptProcessor", &.{ js.createNumber(4096), input_channels, output_channels }).view(.object);
+    defer node.deinit();
+
+    context.set("node", node.toValue());
+
+    {
+        const audio_process_event = js.createFunction(audioProcessEvent);
+        defer audio_process_event.deinit();
+        node.set("onaudioprocess", audio_process_event.toValue());
+    }
+
+    {
+        const destination = context.get("destination").view(.object);
+        defer destination.deinit();
+        _ = node.call("connect", &.{destination.toValue()});
+    }
+
+    return Device{
+        .context = context,
+    };
+}
+
+fn audioProcessEvent(args: js.Object, _: usize) js.Value {
+    const audio_event = args.getIndex(0).view(.object);
+    _ = audio_event;
+    return js.createUndefined();
+}
+
+pub fn outputDeviceIterator(audio: Audio) DeviceIterator {
+    return .{ .audio = audio, .mode = .output };
+}
+
+pub fn inputDeviceIterator(audio: Audio) DeviceIterator {
+    return .{ .audio = audio, .mode = .input };
+}