#include "dialogcontrolpassword.h"
#include "ui_dialogcontrolpassword.h"

#include <QFont>
#include <QGridLayout>
#include <QHBoxLayout>
#include <QKeyEvent>
#include <QLabel>
#include <QList>
#include <QPushButton>
#include <QShowEvent>
#include <QSizePolicy>
#include <QTimer>

namespace {

const char* kDigitBoxStyleEmpty =
    "color: rgb(221, 225, 233);"
    "background-color: rgb(47, 48, 52);"
    "border: 1px solid rgb(70, 72, 78);"
    "border-radius: 4px;";

const char* kDigitBoxStyleFilled =
    "color: rgb(221, 225, 233);"
    "background-color: rgb(60, 120, 180);"
    "border: 1px solid rgb(80, 140, 200);"
    "border-radius: 4px;";

const char* kKeypadButtonStyle =
    "QPushButton {"
    "  background-color: rgb(47, 48, 52);"
    "  color: rgb(221, 225, 233);"
    "  border: 1px solid rgb(70, 72, 78);"
    "  border-radius: 4px;"
    "}"
    "QPushButton:hover {"
    "  background-color: rgb(70, 72, 78);"
    "}"
    "QPushButton:pressed {"
    "  background-color: rgb(40, 100, 160);"
    "}";

QPushButton* MakeKeypadButton(QWidget* parent, const QString& text)
{
    auto* button = new QPushButton(text, parent);
    button->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    button->setMinimumSize(90, 72);
    button->setFocusPolicy(Qt::NoFocus);
    button->setStyleSheet(QString::fromLatin1(kKeypadButtonStyle));
    QFont font = button->font();
    font.setPointSize(22);
    font.setBold(true);
    button->setFont(font);
    return button;
}

} // namespace

DialogControlPassword::DialogControlPassword(QWidget* parent)
    : QDialog(parent)
    , ui(new Ui::DialogControlPassword)
{
    ui->setupUi(this);
    setModal(true);
    setWindowModality(Qt::ApplicationModal);
    setFixedSize(520, 720);
    setFocusPolicy(Qt::StrongFocus);
    if (ui->btnOK) {
        ui->btnOK->setFocusPolicy(Qt::NoFocus);
    }
    if (ui->btnCancel) {
        ui->btnCancel->setFocusPolicy(Qt::NoFocus);
    }
    ApplyUiFont();
    if (ui->label_title) {
        QFont titleFont = ui->label_title->font();
        titleFont.setPointSize(20);
        titleFont.setBold(true);
        ui->label_title->setFont(titleFont);
    }
    BuildDigitBoxes();
    BuildKeypad();
    UpdateOkEnabled();
}

DialogControlPassword::~DialogControlPassword()
{
    delete ui;
}

void DialogControlPassword::SetTitle(const QString& title)
{
    const QString windowTitle = title.isEmpty()
        ? QStringLiteral("控制密码")
        : title;
    setWindowTitle(windowTitle);
    if (ui && ui->label_title) {
        ui->label_title->setText(windowTitle);
    }
}

QString DialogControlPassword::Password() const
{
    return m_password;
}

void DialogControlPassword::SetError(const QString& text)
{
    if (!ui || !ui->label_error) {
        return;
    }
    ui->label_error->setText(text);
}

void DialogControlPassword::SetPasswordChecker(
    const std::function<bool(const QString&)>& checker)
{
    m_passwordChecker = checker;
}

void DialogControlPassword::on_btnOK_clicked()
{
    TryAccept();
}

void DialogControlPassword::on_btnCancel_clicked()
{
    reject();
}

void DialogControlPassword::ApplyUiFont()
{
    QFont font;
    font.setPointSize(16);
    setFont(font);
    const QList<QWidget*> widgets = findChildren<QWidget*>();
    for (QWidget* widget : widgets) {
        widget->setFont(font);
    }
}

void DialogControlPassword::BuildDigitBoxes()
{
    if (!ui || !ui->widget_digits) {
        return;
    }

    auto* layout = new QHBoxLayout(ui->widget_digits);
    layout->setContentsMargins(0, 0, 0, 0);
    layout->setSpacing(10);
    m_digitLabels.clear();
    m_digitLabels.reserve(kPasswordLength);
    for (int i = 0; i < kPasswordLength; ++i) {
        auto* digitLabel = new QLabel(ui->widget_digits);
        digitLabel->setAlignment(Qt::AlignCenter);
        digitLabel->setMinimumSize(56, 56);
        QFont digitFont = digitLabel->font();
        digitFont.setPointSize(22);
        digitFont.setBold(true);
        digitLabel->setFont(digitFont);
        layout->addWidget(digitLabel);
        m_digitLabels.append(digitLabel);
    }
    RefreshDigits();
}

void DialogControlPassword::BuildKeypad()
{
    if (!ui || !ui->widget_keypad) {
        return;
    }

    auto* layout = new QGridLayout(ui->widget_keypad);
    layout->setContentsMargins(0, 0, 0, 0);
    layout->setHorizontalSpacing(12);
    layout->setVerticalSpacing(12);

    const int keys[9] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
    for (int i = 0; i < 9; ++i) {
        const int digit = keys[i];
        QPushButton* button = MakeKeypadButton(
            ui->widget_keypad,
            QString::number(digit));
        connect(button, &QPushButton::clicked, this, [this, digit]() {
            AppendDigit(QChar('0' + digit));
        });
        layout->addWidget(button, i / 3, i % 3);
    }

    QPushButton* backButton = MakeKeypadButton(
        ui->widget_keypad,
        QStringLiteral("删除"));
    connect(backButton, &QPushButton::clicked, this, [this]() {
        RemoveLastDigit();
    });
    layout->addWidget(backButton, 3, 0);

    QPushButton* zeroButton = MakeKeypadButton(
        ui->widget_keypad,
        QStringLiteral("0"));
    connect(zeroButton, &QPushButton::clicked, this, [this]() {
        AppendDigit(QLatin1Char('0'));
    });
    layout->addWidget(zeroButton, 3, 1);

    QPushButton* clearButton = MakeKeypadButton(
        ui->widget_keypad,
        QStringLiteral("清空"));
    connect(clearButton, &QPushButton::clicked, this, [this]() {
        ClearPassword();
    });
    layout->addWidget(clearButton, 3, 2);
}

void DialogControlPassword::AppendDigit(QChar digit)
{
    if (!digit.isDigit() || m_password.size() >= kPasswordLength) {
        return;
    }
    m_password.append(digit);
    SetError(QString());
    RefreshDigits();
    // 满 6 位后自动校验，正确关闭窗口，错误提示并清空。
    if (m_password.size() == kPasswordLength) {
        QTimer::singleShot(50, this, [this]() {
            TryAccept();
        });
    }
}

void DialogControlPassword::RemoveLastDigit()
{
    if (m_password.isEmpty()) {
        return;
    }
    m_password.chop(1);
    SetError(QString());
    RefreshDigits();
}

void DialogControlPassword::ClearPassword()
{
    if (m_password.isEmpty()) {
        RefreshDigits();
        return;
    }
    m_password.clear();
    RefreshDigits();
}

void DialogControlPassword::RefreshDigits()
{
    for (int i = 0; i < m_digitLabels.size(); ++i) {
        QLabel* digitLabel = m_digitLabels[i];
        if (!digitLabel) {
            continue;
        }
        const bool filled = i < m_password.size();
        digitLabel->setText(filled ? QStringLiteral("●") : QString());
        digitLabel->setStyleSheet(QString::fromLatin1(
            filled ? kDigitBoxStyleFilled : kDigitBoxStyleEmpty));
    }
    UpdateOkEnabled();
}

void DialogControlPassword::UpdateOkEnabled()
{
    if (ui && ui->btnOK) {
        ui->btnOK->setEnabled(m_password.size() == kPasswordLength);
    }
}

void DialogControlPassword::TryAccept()
{
    if (m_password.size() != kPasswordLength) {
        SetError(QStringLiteral("请输入6位数字密码"));
        return;
    }
    if (m_passwordChecker && !m_passwordChecker(m_password)) {
        SetError(QStringLiteral("密码错误"));
        ClearPassword();
        return;
    }
    accept();
}

void DialogControlPassword::showEvent(QShowEvent* event)
{
    QDialog::showEvent(event);
    ClearPassword();
    SetError(QString());
    setFocus();
}

void DialogControlPassword::keyPressEvent(QKeyEvent* event)
{
    if (!event) {
        return;
    }
    if (event->key() == Qt::Key_Escape) {
        reject();
        return;
    }
    if (event->key() == Qt::Key_Return || event->key() == Qt::Key_Enter) {
        on_btnOK_clicked();
        return;
    }
    if (event->key() == Qt::Key_Backspace) {
        RemoveLastDigit();
        return;
    }
    const QString text = event->text();
    if (text.size() == 1 && text[0].isDigit()) {
        AppendDigit(text[0]);
        return;
    }
    QDialog::keyPressEvent(event);
}