// SPDX-License-Identifier: GPL-2.0+
/*******************************************************************************
 * QtMips - MIPS 32-bit Architecture Subset Simulator
 *
 * Implemented to support following courses:
 *
 *   B35APO - Computer Architectures
 *   https://cw.fel.cvut.cz/wiki/courses/b35apo
 *
 *   B4M35PAP - Advanced Computer Architectures
 *   https://cw.fel.cvut.cz/wiki/courses/b4m35pap/start
 *
 * Copyright (c) 2017-2019 Karel Koci<cynerd@email.cz>
 * Copyright (c) 2019      Pavel Pisa <pisa@cmp.felk.cvut.cz>
 *
 * Faculty of Electrical Engineering (http://www.fel.cvut.cz)
 * Czech Technical University        (http://www.cvut.cz/)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301, USA.
 *
 ******************************************************************************/

#include "registersdock.h"

static const QString labels[] = {
    "zero",
    "at",
    "v0",
    "v1",
    "a0",
    "a1",
    "a2",
    "a3",
    "t0",
    "t1",
    "t2",
    "t3",
    "t4",
    "t5",
    "t6",
    "t7",
    "s0",
    "s1",
    "s2",
    "s3",
    "s4",
    "s5",
    "s6",
    "s7",
    "t8",
    "t9",
    "k0",
    "k1",
    "gp",
    "sp",
    "fp",
    "ra"
};

RegistersDock::RegistersDock(QWidget *parent) : QDockWidget(parent) {
    static const QColor defaultTextColor(0, 0, 0);

    scrollarea = new QScrollArea(this);
    scrollarea->setWidgetResizable(true);
    widg = new StaticTable(scrollarea);
    gp_highlighted = 0;
    hi_highlighted = false;
    lo_highlighted = false;

    pal_normal = palette();
    pal_normal.setColor(QPalette::WindowText, defaultTextColor);

#define INIT(X, LABEL) do{ \
        X = new QLabel("0x00000000", widg); \
        X->setFixedSize(X->sizeHint()); \
        X->setText(""); \
	X->setPalette(pal_normal); \
        X->setTextInteractionFlags(Qt::TextSelectableByMouse); \
	QLabel *l = new QLabel(LABEL, widg); \
	l->setPalette(pal_normal); \
        widg->addRow({l, X}); \
    } while(false)

    for (int i = 0; i < 32; i++)
        INIT(gp[i], QString("$") + QString::number(i) + QString("/") + labels[i]);
    INIT(pc, "pc");
    INIT(lo, "lo");
    INIT(hi, "hi");
#undef INIT
    scrollarea->setWidget(widg);

    setWidget(scrollarea);
    setObjectName("Registers");
    setWindowTitle("Registers");

    pal_updated = pal_normal;
    pal_read = pal_normal;
    pal_updated.setColor(QPalette::WindowText, QColor(240, 0, 0));
    pal_read.setColor(QPalette::WindowText, QColor(0, 0, 240));
}

RegistersDock::~RegistersDock() {
    delete pc;
    delete hi;
    delete lo;
    for (int i = 0; i < 32; i++)
        delete gp[i];
    delete widg;
    delete scrollarea;
}

void RegistersDock::setup(machine::QtMipsMachine *machine) {
    if (machine == nullptr) {
        // Reset data
        pc->setText("");
        hi->setText("");
        lo->setText("");
        for (int i = 0; i < 32; i++)
            gp[i]->setText("");
        return;
    }

    const machine::Registers *regs = machine->registers();

    // Load values
    labelVal(pc, regs->read_pc());
    labelVal(hi, regs->read_hi_lo(true));
    labelVal(lo, regs->read_hi_lo(false));
    for (int i = 0; i < 32; i++)
        labelVal(gp[i], regs->read_gp(i));

    connect(regs, SIGNAL(pc_update(std::uint32_t)), this, SLOT(pc_changed(std::uint32_t)));
    connect(regs, SIGNAL(gp_update(std::uint8_t,std::uint32_t)), this, SLOT(gp_changed(std::uint8_t,std::uint32_t)));
    connect(regs, SIGNAL(hi_lo_update(bool,std::uint32_t)), this, SLOT(hi_lo_changed(bool,std::uint32_t)));
    connect(regs, SIGNAL(gp_read(std::uint8_t,std::uint32_t)), this, SLOT(gp_read(std::uint8_t,std::uint32_t)));
    connect(regs, SIGNAL(hi_lo_read(bool,std::uint32_t)), this, SLOT(hi_lo_read(bool,std::uint32_t)));
    connect(machine, SIGNAL(tick()), this, SLOT(clear_highlights()));
}

void RegistersDock::pc_changed(std::uint32_t val) {
    labelVal(pc, val);
}

void RegistersDock::gp_changed(std::uint8_t i, std::uint32_t val) {
    SANITY_ASSERT(i < 32, QString("RegistersDock received signal with invalid gp register: ") + QString::number(i));
    labelVal(gp[i], val);
    gp[i]->setPalette(pal_updated);
    gp_highlighted |= 1 << i;
}

void RegistersDock::gp_read(std::uint8_t i, std::uint32_t val) {
    (void)val;
    SANITY_ASSERT(i < 32, QString("RegistersDock received signal with invalid gp register: ") + QString::number(i));
    if (!(gp_highlighted & (1 << i))) {
        gp[i]->setPalette(pal_read);
        gp_highlighted |= 1 << i;
    }
}

void RegistersDock::hi_lo_changed(bool hi, std::uint32_t val) {
    if (hi) {
        labelVal(this->hi, val);
        this->hi->setPalette(pal_updated);
        hi_highlighted = true;
    } else {
        labelVal(lo, val);
        this->lo->setPalette(pal_updated);
        lo_highlighted = true;
    }
}

void RegistersDock::hi_lo_read(bool hi, std::uint32_t val) {
    (void)val;
    if (hi) {
        if (!hi_highlighted)
            this->hi->setPalette(pal_read);
        hi_highlighted = true;
    } else {
        if (!lo_highlighted)
            this->lo->setPalette(pal_read);
        lo_highlighted = true;
    }
}

void RegistersDock::clear_highlights() {
    if (hi_highlighted)
        this->hi->setPalette(pal_normal);
    if (lo_highlighted)
        this->lo->setPalette(pal_normal);
    if (gp_highlighted != 0) {
        for (int i = 0; i < 32; i++) {
            if (gp_highlighted & (1 << i))
                gp[i]->setPalette(pal_normal);
        }
    }
    gp_highlighted = 0;
    hi_highlighted = false;
    lo_highlighted = false;
}

void RegistersDock::labelVal(QLabel *label, std::uint32_t value) {
    QString t = QString("0x") + QString::number(value, 16);
    label->setText(t);
}