//! PS/2 Mouse Driver
//!
//! Spawned by the ps2-bus driver once the controller is initialized and port 2
//! has passed its interface test and device reset. The bus driver hands us our
//! device HID as argv[1]; we use it to locate our own device descriptor.

const std = @import("std");
const runtime = @import("runtime");
const ps2 = @import("ps2-library.zig");
const device = runtime.device;

fn writeLine(comptime fmt: []const u8, arguments: anytype) void {
    var line: [128]u8 = undefined;
    _ = runtime.system.write(std.fmt.bufPrint(&line, fmt, arguments) catch return);
}

pub fn main(init: runtime.process.Init) void {
    const hid = init.arguments.get(1).?;

    if (hid.len == 0) {
        _ = runtime.system.write("system/drivers/ps2-bus/mouse: no HID argument\n");
        return;
    }
    writeLine("system/drivers/ps2-bus/mouse: starting for hid {s}\n", .{hid});

    const buffer = runtime.allocator().alloc(device.DeviceDescriptor, 64) catch {
        _ = runtime.system.write("system/drivers/ps2-bus/mouse: out of memory\n");
        return;
    };
    const mouse_device_descriptor = device.findDeviceDescriptorByHid(buffer, hid) orelse {
        writeLine("system/drivers/ps2-bus/mouse: no device for hid {s}\n", .{hid});
        return;
    };

    // The mouse's own node (PNP0F13) carries IRQ12 and is not claimed by the bus,
    // so this driver takes exclusive ownership of it. Port IO still goes through
    // the bus, which owns the shared 8042 ports.
    if (!device.claim(mouse_device_descriptor.id)) {
        writeLine("system/drivers/ps2-bus/mouse: unable to claim device for hid {s}\n", .{hid});
        return;
    }
    writeLine("system/drivers/ps2-bus/mouse: claimed device for hid {s}\n", .{hid});

    // Broadcast mouse events through the input service so programs can listen for them
    // (docs/input.md). As with the keyboard, decoding real PS/2 mouse packets is a
    // follow-up; for now we publish the synthetic stand-in stream. The fan-out path is
    // real, only the source of the movement is placeholder.
    var source = runtime.input.connectSource() orelse {
        _ = runtime.system.write("system/drivers/ps2-bus/mouse: input service unavailable\n");
        return;
    };
    _ = runtime.system.write("system/drivers/ps2-bus/mouse: ok\n");

    var step: usize = 0;
    while (true) : (step +%= 1) {
        _ = source.publishMouseEvent(runtime.input.syntheticMouseEvent(step));
        runtime.system.sleep(200);
    }
}

pub const panic = runtime.panic;
comptime {
    _ = &runtime.start._start;
}