// SPDX-FileCopyrightText: 2024 Himbeer <himbeer@disroot.org>
//
// SPDX-License-Identifier: AGPL-3.0-or-later

const instructions = @import("instructions.zig");

pub const Error = error{
    Success,
    Failed,
    NotSupported,
    InvalidParam,
    Denied,
    InvalidAddr,
    AlreadyAvail,
    AlreadyStarted,
    AlreadyStopped,
    NoSharedMem,
    Unknown,
};

pub fn errorFromCode(code: isize) Error {
    return switch (code) {
        0 => Error.Success,
        -1 => Error.Failed,
        -2 => Error.NotSupported,
        -3 => Error.InvalidParam,
        -4 => Error.Denied,
        -5 => Error.InvalidAddr,
        -6 => Error.AlreadyAvail,
        -7 => Error.AlreadyStarted,
        -8 => Error.AlreadyStopped,
        -9 => Error.NoSharedMem,
        else => Error.Unknown,
    };
}

const BaseExtId: usize = 0x10;

const BaseFnId = enum(usize) {
    GetSpecVer = 0,
    GetImpId = 1,
    GetImpVer = 2,
    ProbeExt = 3,
    GetMVendorId = 4,
    GetMArchId = 5,
    GetMImpId = 6,
};

pub const ImpId = enum(isize) {
    Bbl = 0,
    OpenSbi = 1,
    Xvisor = 2,
    Kvm = 3,
    RustSbi = 4,
    Diosix = 5,
    Coffer = 6,
    Xen = 7,
    PolarFire = 8,
    _,
};

pub fn specVer() !isize {
    const ret = instructions.ecall(BaseExtId, @intFromEnum(BaseFnId.GetSpecVer), 0, 0, 0);
    if (ret.err != 0) {
        return errorFromCode(ret.err);
    }

    return ret.val;
}

pub fn impId() !ImpId {
    const ret = instructions.ecall(BaseExtId, @intFromEnum(BaseFnId.GetImpId), 0, 0, 0);
    if (ret.err != 0) {
        return errorFromCode(ret.err);
    }

    return @enumFromInt(ret.val);
}

pub fn impVer() !isize {
    const ret = instructions.ecall(BaseExtId, @intFromEnum(BaseFnId.GetImpVer), 0, 0, 0);
    if (ret.err != 0) {
        return errorFromCode(ret.err);
    }

    return ret.val;
}

pub fn probeExt(ext_id: usize) !bool {
    const ret = instructions.ecall(BaseExtId, @intFromEnum(BaseFnId.ProbeExt), ext_id, 0, 0);
    if (ret.err != 0) {
        return errorFromCode(ret.err);
    }

    return ret.val != 0;
}

pub fn mVendorId() !isize {
    const ret = instructions.ecall(BaseExtId, @intFromEnum(BaseFnId.GetMVendorId), 0, 0, 0);
    if (ret.err != 0) {
        return errorFromCode(ret.err);
    }

    return ret.val;
}

pub fn mArchId() !isize {
    const ret = instructions.ecall(BaseExtId, @intFromEnum(BaseFnId.GetMarchId), 0, 0, 0);
    if (ret.err != 0) {
        return errorFromCode(ret.err);
    }

    return ret.val;
}

pub fn mImpId() !isize {
    const ret = instructions.ecall(BaseExtId, @intFromEnum(BaseFnId.GetMImpId), 0, 0, 0);
    if (ret.err != 0) {
        return errorFromCode(ret.err);
    }

    return ret.val;
}