//! ACPI / PnP hardware-ID (`_HID`) names: the flat analog of pci-class.zig for
//! `acpi_device` nodes. Unlike PCI, ACPI has no class/subclass/prog-IF taxonomy — a
//! device's identity *is* its `_HID` string (`PNP0303` simply means "PS/2 keyboard"),
//! so this is a plain id -> description registry rather than a hierarchical decoder.
//! The well-known PnP/ACPI IDs; vendor-specific ids (e.g. `QEMU0002`, `INTC1234`) have
//! no standard name and return "". Pure reference data, so it is shared by kernel
//! discovery (the device-tree dump) and any user-space tool.

const std = @import("std");

const Entry = struct { hid: []const u8, name: []const u8 };

/// The common standard PnP/ACPI hardware IDs. Prefix ranges hint at the grouping
/// (PNP03xx keyboards, PNP0Fxx pointing devices, PNP0Cxx ACPI power/thermal,
/// PNP0Axx buses), but there is no formal hierarchy — hence a flat table.
const table = [_]Entry{
    .{ .hid = "PNP0000", .name = "Programmable Interrupt Controller (PIC)" },
    .{ .hid = "PNP0100", .name = "System Timer (PIT)" },
    .{ .hid = "PNP0103", .name = "High Precision Event Timer (HPET)" },
    .{ .hid = "PNP0200", .name = "DMA Controller" },
    .{ .hid = "PNP0303", .name = "PS/2 Keyboard" },
    .{ .hid = "PNP0400", .name = "Standard LPT Parallel Port" },
    .{ .hid = "PNP0401", .name = "ECP Parallel Port" },
    .{ .hid = "PNP0501", .name = "16550A-compatible Serial Port" },
    .{ .hid = "PNP0700", .name = "PC Floppy Disk Controller" },
    .{ .hid = "PNP0800", .name = "System Speaker" },
    .{ .hid = "PNP0A03", .name = "PCI Bus" },
    .{ .hid = "PNP0A05", .name = "Generic Container Device" },
    .{ .hid = "PNP0A06", .name = "Generic Container Device" },
    .{ .hid = "PNP0A08", .name = "PCI Express Root Bridge" },
    .{ .hid = "PNP0B00", .name = "Real-Time Clock (RTC)" },
    .{ .hid = "PNP0C01", .name = "System Board" },
    .{ .hid = "PNP0C02", .name = "Motherboard Reserved Resources" },
    .{ .hid = "PNP0C04", .name = "Math Coprocessor" },
    .{ .hid = "PNP0C08", .name = "ACPI System Board" },
    .{ .hid = "PNP0C09", .name = "ACPI Embedded Controller" },
    .{ .hid = "PNP0C0A", .name = "ACPI Control Method Battery" },
    .{ .hid = "PNP0C0B", .name = "ACPI Fan" },
    .{ .hid = "PNP0C0C", .name = "ACPI Power Button" },
    .{ .hid = "PNP0C0D", .name = "ACPI Lid" },
    .{ .hid = "PNP0C0E", .name = "ACPI Sleep Button" },
    .{ .hid = "PNP0C0F", .name = "PCI Interrupt Link Device" },
    .{ .hid = "PNP0F03", .name = "Microsoft PS/2 Mouse" },
    .{ .hid = "PNP0F13", .name = "PS/2 Mouse" },
    .{ .hid = "ACPI0003", .name = "AC Adapter" },
    .{ .hid = "ACPI0007", .name = "Processor Device" },
    .{ .hid = "ACPI000C", .name = "Processor Aggregator" },
    .{ .hid = "ACPI0010", .name = "Processor Container" },
};

/// The human-readable name for a `_HID`, or "" if it is not a known standard id
/// (vendor-specific ids have no registry name — callers just print the raw HID).
pub fn description(hid: []const u8) []const u8 {
    for (table) |entry| {
        if (std.mem.eql(u8, entry.hid, hid)) return entry.name;
    }
    return "";
}

test "decodes standard PnP/ACPI ids and leaves the rest alone" {
    const eq = std.testing.expectEqualStrings;
    try eq("PS/2 Keyboard", description("PNP0303"));
    try eq("PS/2 Mouse", description("PNP0F13"));
    try eq("PCI Express Root Bridge", description("PNP0A08"));
    try eq("Real-Time Clock (RTC)", description("PNP0B00"));
    try eq("", description("QEMU0002")); // vendor-specific: no standard name
    try eq("", description("")); // no HID at all
}