"""设计系统：Apple 高级浅色主题 + 浅深双模式。

单一真相源 — 所有颜色 / 间距 / 圆角 / 字号在本模块定义，
通过 build_qss(mode) 拼成完整 QSS 字符串应用到 QApplication。

跟随系统切换：监听 QGuiApplication.styleHints().colorSchemeChanged，
macOS 按时间自动切深色 / Windows 11 系统级深浅都会自动响应。

业务代码不要写 inline setStyleSheet — 通过 setObjectName / setProperty
让全局 QSS 命中。状态色（success/warning/danger）用 setProperty('status', ...)。
"""
from __future__ import annotations

from PySide6.QtCore import QObject, Qt, Signal
from PySide6.QtGui import QGuiApplication
from PySide6.QtWidgets import QApplication

# =============================================================================
# 设计令牌
# =============================================================================

FONT_STACK = (
    '"-apple-system", "SF Pro Text", "PingFang SC", '
    '"Microsoft YaHei UI", "Segoe UI Variable", "Segoe UI", sans-serif'
)

TOKENS_LIGHT: dict[str, str] = {
    # 表面层级
    "bg_canvas": "#fbfbfd",
    "bg_surface": "#ffffff",
    "bg_elevated": "#ffffff",
    "bg_subtle": "#f4f4f7",
    "bg_hover": "#f0f0f3",

    # 文字层级
    "text_primary": "#1d1d1f",
    "text_secondary": "#6e6e73",
    "text_tertiary": "#86868b",
    "text_on_accent": "#ffffff",
    "text_on_danger": "#ffffff",

    # 边框 / 分隔
    "border_default": "rgba(0, 0, 0, 0.10)",
    "border_strong": "rgba(0, 0, 0, 0.18)",
    "border_focus": "#0071e3",
    "divider": "rgba(0, 0, 0, 0.06)",

    # 主色（accent）
    "accent": "#0071e3",
    "accent_hover": "#0077ed",
    "accent_pressed": "#0062c4",
    "accent_subtle": "rgba(0, 113, 227, 0.08)",
    "accent_subtle_hover": "rgba(0, 113, 227, 0.14)",

    # 状态色
    "success": "#34c759",
    "warning": "#ff9500",
    "danger": "#ff3b30",
    "danger_hover": "#ff5247",
    "danger_subtle": "rgba(255, 59, 48, 0.10)",
}

TOKENS_DARK: dict[str, str] = {
    "bg_canvas": "#1a1a1c",
    "bg_surface": "#2c2c2e",
    "bg_elevated": "#3a3a3c",
    "bg_subtle": "#242426",
    "bg_hover": "#34343a",

    "text_primary": "#ffffff",
    "text_secondary": "#98989d",
    "text_tertiary": "#6e6e73",
    "text_on_accent": "#ffffff",
    "text_on_danger": "#ffffff",

    "border_default": "rgba(255, 255, 255, 0.10)",
    "border_strong": "rgba(255, 255, 255, 0.20)",
    "border_focus": "#0a84ff",
    "divider": "rgba(255, 255, 255, 0.06)",

    "accent": "#0a84ff",
    "accent_hover": "#1d8cff",
    "accent_pressed": "#006edc",
    "accent_subtle": "rgba(10, 132, 255, 0.16)",
    "accent_subtle_hover": "rgba(10, 132, 255, 0.24)",

    "success": "#30d158",
    "warning": "#ff9f0a",
    "danger": "#ff453a",
    "danger_hover": "#ff5b50",
    "danger_subtle": "rgba(255, 69, 58, 0.16)",
}

# 尺寸 / 圆角 / 间距 ─ 浅深一致
SIZES: dict[str, str] = {
    "radius_sm": "4px",
    "radius_md": "8px",
    "radius_lg": "12px",
    "radius_pill": "980px",

    "space_1": "4px",
    "space_2": "8px",
    "space_3": "12px",
    "space_4": "16px",
    "space_5": "20px",
    "space_6": "24px",

    "control_h_sm": "26px",
    "control_h_md": "32px",
    "control_h_lg": "40px",

    "font_xs": "10pt",
    "font_sm": "11pt",
    "font_base": "12pt",
    "font_lg": "14pt",
    "font_xl": "17pt",
}


# =============================================================================
# QSS 构建
# =============================================================================

def build_qss(mode: str) -> str:
    """根据 mode（'light'/'dark'）拼出完整 QSS。"""
    c = TOKENS_DARK if mode == "dark" else TOKENS_LIGHT
    s = SIZES
    f = FONT_STACK

    return f"""
/* ========== 全局 ========== */
* {{
    font-family: {f};
    color: {c['text_primary']};
}}

QWidget {{
    background-color: {c['bg_canvas']};
    color: {c['text_primary']};
    font-size: {s['font_base']};
}}

QMainWindow, QDialog {{
    background-color: {c['bg_canvas']};
}}

/* 二级弹窗（QMessageBox 等）走 surface 颜色，凸出于主窗口 */
QMessageBox {{
    background-color: {c['bg_surface']};
}}
QMessageBox QLabel {{
    background: transparent;
    color: {c['text_primary']};
    font-size: {s['font_base']};
}}

/* ========== 文字 ========== */
QLabel {{
    background: transparent;
    color: {c['text_primary']};
}}
QLabel[role="secondary"] {{
    color: {c['text_secondary']};
}}
QLabel[role="muted"] {{
    color: {c['text_tertiary']};
    font-size: {s['font_sm']};
}}
QLabel[role="caption"] {{
    color: {c['text_secondary']};
    font-size: {s['font_xs']};
    text-transform: uppercase;
    letter-spacing: 1px;
}}
QLabel[role="title"] {{
    color: {c['text_primary']};
    font-size: {s['font_xl']};
    font-weight: 600;
}}

/* 状态色 — 业务用 setProperty('status', '...') 命中 */
QLabel[status="success"] {{ color: {c['success']}; }}
QLabel[status="warning"] {{ color: {c['warning']}; }}
QLabel[status="danger"]  {{ color: {c['danger']}; }}
QLabel[status="muted"]   {{ color: {c['text_tertiary']}; }}
QLabel[status="info"]    {{ color: {c['accent']}; }}

/* ========== 卡片 / GroupBox ========== */
QGroupBox {{
    background-color: {c['bg_surface']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    margin-top: 14px;
    padding: {s['space_4']} {s['space_3']} {s['space_3']} {s['space_3']};
    font-weight: 600;
    font-size: {s['font_sm']};
    color: {c['text_secondary']};
}}
QGroupBox::title {{
    subcontrol-origin: margin;
    subcontrol-position: top left;
    left: {s['space_3']};
    padding: 0 {s['space_2']};
    color: {c['text_secondary']};
    background: transparent;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: {s['font_xs']};
}}

/* ========== 按钮 ========== */
QPushButton {{
    background-color: {c['bg_surface']};
    color: {c['text_primary']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    padding: 6px 14px;
    min-height: {s['control_h_md']};
    font-size: {s['font_sm']};
    font-weight: 500;
}}
QPushButton:hover {{
    background-color: {c['bg_hover']};
    border-color: {c['border_strong']};
}}
QPushButton:pressed {{
    background-color: {c['bg_subtle']};
}}
QPushButton:disabled {{
    color: {c['text_tertiary']};
    background-color: {c['bg_subtle']};
    border-color: {c['border_default']};
}}
QPushButton:focus {{
    outline: none;
    border-color: {c['accent']};
}}

/* 主按钮（"生成图片"等）— pill 圆角 + 实色背景 */
QPushButton[variant="primary"] {{
    background-color: {c['accent']};
    color: {c['text_on_accent']};
    border: 1px solid {c['accent']};
    border-radius: {s['radius_pill']};
    padding: 8px 22px;
    min-height: {s['control_h_lg']};
    font-weight: 600;
}}
QPushButton[variant="primary"]:hover {{
    background-color: {c['accent_hover']};
    border-color: {c['accent_hover']};
}}
QPushButton[variant="primary"]:pressed {{
    background-color: {c['accent_pressed']};
    border-color: {c['accent_pressed']};
}}
QPushButton[variant="primary"]:disabled {{
    background-color: {c['accent_subtle']};
    color: {c['text_tertiary']};
    border-color: transparent;
}}

/* 危险按钮 */
QPushButton[variant="danger"] {{
    background-color: {c['bg_surface']};
    color: {c['danger']};
    border: 1px solid {c['danger']};
}}
QPushButton[variant="danger"]:hover {{
    background-color: {c['danger_subtle']};
}}
QPushButton[variant="danger"]:pressed {{
    background-color: {c['danger']};
    color: {c['text_on_danger']};
}}

/* 幽灵按钮（图标按钮等） */
QPushButton[variant="ghost"] {{
    background-color: transparent;
    border: 1px solid transparent;
    color: {c['text_secondary']};
}}
QPushButton[variant="ghost"]:hover {{
    background-color: {c['accent_subtle']};
    color: {c['accent']};
}}

/* 短暂成功反馈（"已复制"等，2秒后回退）*/
QPushButton[variant="success-flash"] {{
    background-color: {c['success']};
    color: white;
    border: 1px solid {c['success']};
}}

/* 链接按钮 — 像超链接 */
QPushButton[variant="link"] {{
    background-color: transparent;
    border: none;
    color: {c['accent']};
    padding: 2px 6px;
    min-height: 0;
}}
QPushButton[variant="link"]:hover {{
    color: {c['accent_hover']};
    text-decoration: underline;
}}

/* ========== 输入框 ========== */
QLineEdit, QTextEdit, QPlainTextEdit {{
    background-color: {c['bg_surface']};
    color: {c['text_primary']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    padding: 6px 10px;
    selection-background-color: {c['accent']};
    selection-color: {c['text_on_accent']};
    font-size: {s['font_base']};
}}
QLineEdit:focus, QTextEdit:focus, QPlainTextEdit:focus {{
    border: 2px solid {c['accent']};
    padding: 5px 9px;
}}
QLineEdit:disabled, QTextEdit:disabled, QPlainTextEdit:disabled {{
    background-color: {c['bg_subtle']};
    color: {c['text_tertiary']};
}}
QLineEdit[placeholder="true"], QTextEdit[placeholder="true"] {{
    color: {c['text_tertiary']};
}}

/* ========== 下拉框 ========== */
QComboBox {{
    background-color: {c['bg_surface']};
    color: {c['text_primary']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    padding: 5px 10px;
    min-height: {s['control_h_md']};
    min-width: 100px;
}}
QComboBox:hover {{
    border-color: {c['border_strong']};
}}
QComboBox:focus {{
    border: 2px solid {c['accent']};
    padding: 4px 9px;
}}
QComboBox::drop-down {{
    width: 20px;
    border: none;
    background: transparent;
}}
QComboBox QAbstractItemView {{
    background-color: {c['bg_elevated']};
    color: {c['text_primary']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    selection-background-color: {c['accent_subtle']};
    selection-color: {c['text_primary']};
    padding: 4px;
    outline: none;
}}
QComboBox QAbstractItemView::item {{
    padding: 6px 10px;
    border-radius: {s['radius_sm']};
}}
QComboBox QAbstractItemView::item:hover {{
    background-color: {c['accent_subtle']};
}}

/* ========== Tab ========== */
QTabWidget::pane {{
    border: none;
    background-color: {c['bg_canvas']};
    top: -1px;
}}
QTabWidget::tab-bar {{
    left: 4px;
}}
QTabBar {{
    background: transparent;
    qproperty-drawBase: 0;
}}
QTabBar::tab {{
    background: transparent;
    color: {c['text_secondary']};
    padding: 8px 16px;
    margin: 0 2px;
    border: none;
    border-bottom: 2px solid transparent;
    font-size: {s['font_base']};
    min-width: 80px;
}}
QTabBar::tab:hover {{
    color: {c['text_primary']};
}}
QTabBar::tab:selected {{
    color: {c['accent']};
    border-bottom: 2px solid {c['accent']};
    font-weight: 600;
}}
QTabBar::tab:disabled {{
    color: {c['text_tertiary']};
}}

/* ========== 列表 ========== */
QListWidget, QListView, QTreeWidget, QTreeView {{
    background-color: {c['bg_surface']};
    color: {c['text_primary']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    outline: none;
    padding: 4px;
}}
QListWidget::item, QListView::item {{
    padding: 8px;
    border-radius: {s['radius_sm']};
    color: {c['text_primary']};
}}
QListWidget::item:hover, QListView::item:hover {{
    background-color: {c['bg_hover']};
}}
QListWidget::item:selected, QListView::item:selected {{
    background-color: {c['accent_subtle']};
    color: {c['text_primary']};
}}

/* ========== 滚动区 ========== */
QScrollArea {{
    background-color: {c['bg_canvas']};
    border: none;
}}
QScrollArea > QWidget > QWidget {{
    background-color: transparent;
}}

/* ========== 滚动条（Apple 隐式风格）========== */
QScrollBar:vertical {{
    background: transparent;
    width: 10px;
    margin: 2px;
    border: none;
}}
QScrollBar::handle:vertical {{
    background: {c['border_strong']};
    border-radius: 3px;
    min-height: 30px;
}}
QScrollBar::handle:vertical:hover {{
    background: {c['text_tertiary']};
}}
QScrollBar::add-line:vertical, QScrollBar::sub-line:vertical {{
    height: 0;
    background: transparent;
    border: none;
}}
QScrollBar::add-page:vertical, QScrollBar::sub-page:vertical {{
    background: transparent;
}}

QScrollBar:horizontal {{
    background: transparent;
    height: 10px;
    margin: 2px;
    border: none;
}}
QScrollBar::handle:horizontal {{
    background: {c['border_strong']};
    border-radius: 3px;
    min-width: 30px;
}}
QScrollBar::handle:horizontal:hover {{
    background: {c['text_tertiary']};
}}
QScrollBar::add-line:horizontal, QScrollBar::sub-line:horizontal {{
    width: 0;
    background: transparent;
    border: none;
}}
QScrollBar::add-page:horizontal, QScrollBar::sub-page:horizontal {{
    background: transparent;
}}

/* ========== 进度条 ========== */
QProgressBar {{
    background-color: {c['bg_subtle']};
    border: none;
    border-radius: 4px;
    height: 6px;
    text-align: center;
    color: {c['text_secondary']};
    font-size: {s['font_xs']};
}}
QProgressBar::chunk {{
    background-color: {c['accent']};
    border-radius: 4px;
}}

/* ========== 复选 / 单选 ========== */
QCheckBox, QRadioButton {{
    color: {c['text_primary']};
    spacing: 6px;
    background: transparent;
}}
QCheckBox::indicator, QRadioButton::indicator {{
    width: 16px;
    height: 16px;
}}
QCheckBox::indicator:unchecked {{
    background: {c['bg_surface']};
    border: 1px solid {c['border_strong']};
    border-radius: 3px;
}}
QCheckBox::indicator:checked {{
    background: {c['accent']};
    border: 1px solid {c['accent']};
    border-radius: 3px;
}}
QRadioButton::indicator:unchecked {{
    background: {c['bg_surface']};
    border: 1px solid {c['border_strong']};
    border-radius: 8px;
}}
QRadioButton::indicator:checked {{
    background: {c['accent']};
    border: 1px solid {c['accent']};
    border-radius: 8px;
}}

/* ========== 工具提示 ========== */
QToolTip {{
    background-color: {c['bg_elevated']};
    color: {c['text_primary']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_sm']};
    padding: 4px 8px;
    font-size: {s['font_sm']};
}}

/* ========== 菜单 ========== */
QMenu {{
    background-color: {c['bg_elevated']};
    color: {c['text_primary']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    padding: 4px;
}}
QMenu::item {{
    padding: 6px 16px;
    border-radius: {s['radius_sm']};
}}
QMenu::item:selected {{
    background-color: {c['accent_subtle']};
    color: {c['text_primary']};
}}
QMenu::separator {{
    height: 1px;
    background: {c['divider']};
    margin: 4px 6px;
}}

/* ========== 分割器 ========== */
QSplitter::handle {{
    background-color: {c['divider']};
}}
QSplitter::handle:horizontal {{
    width: 1px;
}}
QSplitter::handle:vertical {{
    height: 1px;
}}

/* ========== 任务队列 sidebar ========== */
#taskQueueSidebar {{
    background-color: {c['bg_surface']};
    border-left: 1px solid {c['divider']};
}}
#sidebarHeader {{
    background-color: {c['bg_surface']};
    border-bottom: 1px solid {c['divider']};
    min-height: 40px;
    max-height: 40px;
}}
#sidebarHeader QLabel {{
    color: {c['text_primary']};
    font-size: {s['font_base']};
    font-weight: 600;
    padding: 0 12px;
}}

/* ========== 登录对话框 ========== */
#loginDialog {{
    background-color: {c['bg_canvas']};
}}
#loginDialog QLabel#loginTitle {{
    font-size: {s['font_xl']};
    font-weight: 600;
    color: {c['text_primary']};
}}
#loginDialog QLabel#loginSubtitle {{
    font-size: {s['font_sm']};
    color: {c['text_secondary']};
}}

/* ========== 预览区占位 ========== */
#previewPlaceholder {{
    color: {c['text_tertiary']};
    background: {c['bg_subtle']};
    border-radius: {s['radius_md']};
}}

/* ========== 参考图拖拽区（drag_state property）========== */
#referenceImageDrop[drag_state="idle"] {{
    border: 2px dashed {c['border_default']};
    border-radius: {s['radius_md']};
    background-color: {c['bg_subtle']};
}}
#referenceImageDrop[drag_state="idle"]:hover {{
    border: 2px dashed {c['accent']};
    background-color: {c['accent_subtle']};
}}
#referenceImageDrop[drag_state="active"] {{
    border: 2px dashed {c['accent']};
    border-radius: {s['radius_md']};
    background-color: {c['accent_subtle']};
}}

/* ========== 已生成图片缩略图卡 ========== */
QLabel[role="thumb"] {{
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_sm']};
    background-color: {c['bg_surface']};
}}
QLabel[role="thumb_index"] {{
    color: {c['text_secondary']};
    font-size: {s['font_base']};
    font-weight: 600;
}}

/* ========== 预览区生成图（result_label / generated_image_label）========== */
QLabel#previewImage {{
    background-color: {c['bg_subtle']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    color: {c['text_tertiary']};
}}
QLabel#previewImage[has_image="true"] {{
    background-color: {c['bg_canvas']};
    border-color: {c['border_default']};
}}

/* ========== 历史详情提示词显示框 ========== */
QLabel#promptDisplay {{
    background-color: {c['bg_subtle']};
    border: 1px solid {c['border_default']};
    border-radius: {s['radius_md']};
    padding: 8px 10px;
    color: {c['text_primary']};
}}

/* ========== 缩略图删除按钮（20x20 紧凑）========== */
QPushButton#thumbDeleteBtn {{
    background-color: {c['danger']};
    color: white;
    border: none;
    border-radius: 3px;
    padding: 0;
    min-height: 0;
    font-size: {s['font_xs']};
    font-weight: 700;
}}
QPushButton#thumbDeleteBtn:hover {{
    background-color: {c['danger_hover']};
}}
"""


# =============================================================================
# 主题管理器
# =============================================================================

def _detect_system_mode() -> str:
    """检测当前系统色彩偏好。Qt 6.5+ 支持，回退到 light。"""
    try:
        scheme = QGuiApplication.styleHints().colorScheme()
        if scheme == Qt.ColorScheme.Dark:
            return "dark"
        return "light"
    except Exception:
        return "light"


class ThemeManager(QObject):
    """全局主题管理器。监听系统色彩偏好变化，自动切换 QSS。

    使用：在 main() 创建 QApplication 后调用 apply_theme(app) 即可。
    业务代码不需要直接接触 ThemeManager。

    通过 force_mode('light'|'dark'|None) 可以强制锁定，传 None 恢复跟随系统。
    """

    theme_changed = Signal(str)  # 'light' | 'dark'

    def __init__(self, app: QApplication):
        super().__init__(app)
        self._app = app
        self._forced_mode: str | None = None
        self._current_mode: str = _detect_system_mode()
        self._apply_qss()

        # 监听系统色彩切换
        try:
            QGuiApplication.styleHints().colorSchemeChanged.connect(
                self._on_system_color_scheme_changed
            )
        except Exception:
            # Qt 版本不支持 / 平台不发射，无所谓
            pass

    def current_mode(self) -> str:
        return self._current_mode

    def force_mode(self, mode: str | None) -> None:
        """锁定主题。None = 跟随系统。"""
        self._forced_mode = mode
        new_mode = mode if mode in ("light", "dark") else _detect_system_mode()
        if new_mode != self._current_mode:
            self._current_mode = new_mode
            self._apply_qss()
            self.theme_changed.emit(new_mode)

    def _on_system_color_scheme_changed(self, scheme) -> None:
        if self._forced_mode in ("light", "dark"):
            return  # 用户锁定模式时不响应系统切换
        new_mode = "dark" if scheme == Qt.ColorScheme.Dark else "light"
        if new_mode != self._current_mode:
            self._current_mode = new_mode
            self._apply_qss()
            self.theme_changed.emit(new_mode)

    def _apply_qss(self) -> None:
        self._app.setStyleSheet(build_qss(self._current_mode))


def apply_theme(app: QApplication) -> ThemeManager:
    """主题应用入口。在 main() 创建 QApplication 后立即调用。

    返回 ThemeManager 实例，调用方应持有引用以保持信号连接（否则会被
    Python GC 当作未引用的 QObject 回收，导致系统切换失效）。
    """
    mgr = ThemeManager(app)
    # 全局可访问点，方便 get_color() 等无 widget 引用的场景
    app.theme_manager = mgr
    return mgr


def get_color(token: str, fallback: str = "#000000") -> str:
    """读取当前主题下的颜色 token。

    用于 widget 内嵌颜色调用（如 QListWidgetItem.setForeground 等），
    QSS 命中不到的渲染层 API。注意：返回的是当前快照，主题切换后需要
    在下一次重绘时重新读取。
    """
    try:
        app = QApplication.instance()
        mgr = getattr(app, "theme_manager", None)
        mode = mgr.current_mode() if mgr else "light"
    except Exception:
        mode = "light"
    table = TOKENS_DARK if mode == "dark" else TOKENS_LIGHT
    return table.get(token, fallback)