"""Tema visual del Studio — aplica los design tokens del Sprint 0 a PySide6.

Los tokens canónicos viven en `docs/design_system.md` y `docs/mockups/_tokens.css`.
Este módulo replica esos valores en Python para construir el QSS (Qt Style Sheets)
y los QPalette necesarios.
"""

from __future__ import annotations

from PySide6.QtGui import QColor, QFont, QFontDatabase, QPalette
from PySide6.QtWidgets import QApplication

# ----- Paleta Deep Ocean (canónica) --------------------------------------

C_ABYSS = "#04111F"
C_MIDNIGHT = "#0A1A2E"
C_STEEL = "#1A2B42"
C_IRON = "#2C3E5C"
C_FOG = "#7C8B9F"
C_SAND = "#E6EAF0"
C_FOAM = "#F2F5F9"
C_CYAN = "#00D9FF"
C_CYAN_DEEP = "#1B7FB5"
C_HORIZON = "#5BC0EB"

C_OK = "#00E08A"
C_INFO = "#5BC0EB"
C_WARN = "#FFB020"
C_HIGH = "#FF8030"
C_EMERGENCY = "#FF3B47"


# ----- Fuentes -----------------------------------------------------------

FAMILY_DISPLAY = "Space Grotesk"
FAMILY_UI = "Inter"
FAMILY_MONO = "JetBrains Mono"

FALLBACK_DISPLAY = "Segoe UI"
FALLBACK_UI = "Segoe UI"
FALLBACK_MONO = "Cascadia Mono"


def best_family(preferred: str, fallback: str) -> str:
    """Devuelve `preferred` si está instalado, si no `fallback`."""
    families = set(QFontDatabase.families())
    if preferred in families:
        return preferred
    return fallback


def display_font(
    point_size: int = 16, weight: QFont.Weight | int = QFont.Weight.DemiBold
) -> QFont:
    f = QFont(best_family(FAMILY_DISPLAY, FALLBACK_DISPLAY))
    f.setPointSize(point_size)
    if isinstance(weight, int):
        # PySide6 6.11 requiere QFont.Weight, no int. Aproximamos.
        if weight <= 300:
            weight = QFont.Weight.Light
        elif weight <= 400:
            weight = QFont.Weight.Normal
        elif weight <= 500:
            weight = QFont.Weight.Medium
        elif weight <= 600:
            weight = QFont.Weight.DemiBold
        elif weight <= 700:
            weight = QFont.Weight.Bold
        else:
            weight = QFont.Weight.Black
    f.setWeight(weight)
    return f


def ui_font(point_size: int = 10) -> QFont:
    f = QFont(best_family(FAMILY_UI, FALLBACK_UI))
    f.setPointSize(point_size)
    return f


def mono_font(point_size: int = 10) -> QFont:
    f = QFont(best_family(FAMILY_MONO, FALLBACK_MONO))
    f.setPointSize(point_size)
    return f


# ----- Stylesheet global -------------------------------------------------


_QSS = f"""
QMainWindow, QDialog, QWidget {{
    background-color: {C_ABYSS};
    color: {C_SAND};
}}

QWidget#topbar {{
    background-color: {C_MIDNIGHT};
    border-bottom: 1px solid {C_STEEL};
}}

QWidget#sidebar {{
    background-color: {C_MIDNIGHT};
    border-right: 1px solid {C_STEEL};
}}

QWidget#statusbar {{
    background-color: {C_MIDNIGHT};
    border-top: 1px solid {C_STEEL};
    color: {C_FOG};
}}

QLabel {{
    color: {C_SAND};
}}

QLabel#title {{
    color: {C_FOAM};
    font-weight: 600;
}}

QLabel#h1 {{
    color: {C_FOAM};
    font-size: 22pt;
    font-weight: 600;
}}

QLabel#caption {{
    color: {C_FOG};
    font-size: 9pt;
}}

QLabel#overline {{
    color: {C_FOG};
    font-size: 9pt;
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
}}

QPushButton {{
    background-color: transparent;
    color: {C_SAND};
    border: 1px solid {C_IRON};
    border-radius: 6px;
    padding: 8px 16px;
    min-width: 80px;
}}
QPushButton:hover {{
    background-color: {C_STEEL};
}}
QPushButton:pressed {{
    background-color: {C_IRON};
}}
QPushButton:disabled {{
    background-color: {C_STEEL};
    color: {C_FOG};
    border-color: transparent;
}}

QPushButton#primary {{
    background-color: {C_CYAN};
    color: {C_ABYSS};
    border: none;
    font-weight: 600;
}}
QPushButton#primary:hover {{
    background-color: {C_HORIZON};
}}

QPushButton#danger {{
    background-color: {C_EMERGENCY};
    color: {C_FOAM};
    border: none;
    font-weight: 700;
}}

QLineEdit, QSpinBox, QDoubleSpinBox, QComboBox, QPlainTextEdit, QTextEdit {{
    background-color: {C_STEEL};
    color: {C_FOAM};
    border: 1px solid {C_IRON};
    border-radius: 4px;
    padding: 6px 10px;
    selection-background-color: {C_CYAN};
    selection-color: {C_ABYSS};
}}
QLineEdit:focus, QSpinBox:focus, QDoubleSpinBox:focus, QComboBox:focus {{
    border-color: {C_CYAN};
}}

QComboBox::drop-down {{
    border: none;
    width: 24px;
}}
QComboBox::down-arrow {{
    image: none;
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 6px solid {C_FOG};
    margin-right: 8px;
}}
QComboBox QAbstractItemView {{
    background-color: {C_MIDNIGHT};
    color: {C_SAND};
    border: 1px solid {C_IRON};
    selection-background-color: {C_CYAN_DEEP};
    selection-color: {C_FOAM};
}}

QCheckBox {{
    color: {C_SAND};
    spacing: 8px;
}}
QCheckBox::indicator {{
    width: 18px;
    height: 18px;
    background-color: {C_STEEL};
    border: 1px solid {C_IRON};
    border-radius: 3px;
}}
QCheckBox::indicator:hover {{
    border-color: {C_CYAN};
}}
QCheckBox::indicator:checked {{
    background-color: {C_CYAN};
    border-color: {C_CYAN};
    image: none;
}}

QListWidget, QTreeWidget, QTableWidget {{
    background-color: {C_MIDNIGHT};
    color: {C_SAND};
    border: 1px solid {C_STEEL};
    border-radius: 6px;
    outline: 0;
}}
QListWidget::item, QTreeWidget::item {{
    padding: 8px 10px;
    border-radius: 4px;
}}
QListWidget::item:hover, QTreeWidget::item:hover {{
    background-color: {C_STEEL};
}}
QListWidget::item:selected, QTreeWidget::item:selected {{
    background-color: rgba(0, 217, 255, 30);
    color: {C_FOAM};
    border-left: 2px solid {C_CYAN};
}}

QHeaderView::section {{
    background-color: {C_MIDNIGHT};
    color: {C_FOG};
    border: none;
    border-right: 1px solid {C_STEEL};
    padding: 8px;
    font-weight: 600;
}}

QMenuBar {{
    background-color: {C_MIDNIGHT};
    color: {C_SAND};
    border-bottom: 1px solid {C_STEEL};
}}
QMenuBar::item {{
    padding: 6px 12px;
    background: transparent;
}}
QMenuBar::item:selected {{
    background-color: {C_STEEL};
    color: {C_CYAN};
}}

QMenu {{
    background-color: {C_MIDNIGHT};
    color: {C_SAND};
    border: 1px solid {C_IRON};
}}
QMenu::item {{
    padding: 6px 24px;
}}
QMenu::item:selected {{
    background-color: {C_STEEL};
    color: {C_CYAN};
}}

QToolBar {{
    background-color: {C_MIDNIGHT};
    border: none;
    spacing: 4px;
    padding: 4px;
}}

QStatusBar {{
    background-color: {C_MIDNIGHT};
    color: {C_FOG};
    border-top: 1px solid {C_STEEL};
}}

QScrollBar:vertical {{
    background: {C_ABYSS};
    width: 12px;
    border: none;
}}
QScrollBar::handle:vertical {{
    background: {C_IRON};
    border-radius: 6px;
    min-height: 30px;
}}
QScrollBar::handle:vertical:hover {{
    background: {C_FOG};
}}
QScrollBar::add-line:vertical, QScrollBar::sub-line:vertical {{
    height: 0;
}}
QScrollBar:horizontal {{
    background: {C_ABYSS};
    height: 12px;
    border: none;
}}
QScrollBar::handle:horizontal {{
    background: {C_IRON};
    border-radius: 6px;
    min-width: 30px;
}}
QScrollBar::add-line:horizontal, QScrollBar::sub-line:horizontal {{
    height: 0;
}}

QGroupBox {{
    color: {C_FOAM};
    border: 1px solid {C_STEEL};
    border-radius: 8px;
    margin-top: 18px;
    padding-top: 12px;
    font-weight: 600;
}}
QGroupBox::title {{
    subcontrol-origin: margin;
    left: 12px;
    padding: 0 6px;
    color: {C_FOG};
    font-size: 9pt;
    letter-spacing: 1.5px;
    text-transform: uppercase;
}}

QWizard {{
    background-color: {C_ABYSS};
}}
QWizard QWidget {{
    background-color: {C_ABYSS};
}}

QToolTip {{
    background-color: {C_MIDNIGHT};
    color: {C_FOAM};
    border: 1px solid {C_CYAN};
    padding: 6px 10px;
    border-radius: 4px;
}}
"""


def apply_theme(app: QApplication) -> None:
    """Aplica el tema completo Deep Ocean a la app.

    - Stylesheet QSS
    - QPalette (para widgets que no respetan QSS)
    - Fuentes default
    """
    app.setStyle("Fusion")

    palette = QPalette()
    palette.setColor(QPalette.Window, QColor(C_ABYSS))
    palette.setColor(QPalette.WindowText, QColor(C_SAND))
    palette.setColor(QPalette.Base, QColor(C_MIDNIGHT))
    palette.setColor(QPalette.AlternateBase, QColor(C_STEEL))
    palette.setColor(QPalette.Text, QColor(C_FOAM))
    palette.setColor(QPalette.Button, QColor(C_STEEL))
    palette.setColor(QPalette.ButtonText, QColor(C_SAND))
    palette.setColor(QPalette.BrightText, QColor(C_EMERGENCY))
    palette.setColor(QPalette.Highlight, QColor(C_CYAN))
    palette.setColor(QPalette.HighlightedText, QColor(C_ABYSS))
    palette.setColor(QPalette.Link, QColor(C_CYAN))
    palette.setColor(QPalette.ToolTipBase, QColor(C_MIDNIGHT))
    palette.setColor(QPalette.ToolTipText, QColor(C_FOAM))
    palette.setColor(QPalette.PlaceholderText, QColor(C_FOG))
    app.setPalette(palette)

    app.setFont(ui_font(10))
    app.setStyleSheet(_QSS)