"""Colours, fonts and the application stylesheet.

One dark theme, tuned by hand: near-black charcoal surfaces a step apart, a
single warm accent (the bolt's amber), and colour used only where it carries
meaning — green for done, red for failed, amber for "needs you".
"""

from __future__ import annotations

import sys

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

BG = "#0e1014"          # window
SURFACE = "#15181e"     # cards, composer
SURFACE_HI = "#1b1f27"  # hover / user bubble
BORDER = "#252a34"
BORDER_HI = "#343b48"
TEXT = "#e7e9ee"
TEXT_DIM = "#9aa1ae"
TEXT_FAINT = "#6b7280"
ACCENT = "#f5b83d"      # the bolt
ACCENT_HI = "#ffc95c"
ACCENT_INK = "#1a1305"  # text on accent
GREEN = "#4ec98a"
RED = "#f06a6a"
BLUE = "#7aa7ff"
CODE = "#e8c98f"       # inline code in replies
DIFF_ADD_BG = "#12291d"
DIFF_DEL_BG = "#301719"

RADIUS = 12
COLUMN_WIDTH = 820  # the transcript's reading column


def _first_available(families, fallback: str) -> str:
    installed = set(QFontDatabase.families())
    for family in families:
        if family in installed:
            return family
    return fallback


def ui_font_family() -> str:
    return _first_available(
        ["Segoe UI Variable Text", "Inter", "SF Pro Text", "Segoe UI", "Cantarell", "Ubuntu"],
        QFont().defaultFamily(),
    )


def mono_font_family() -> str:
    return _first_available(
        ["Cascadia Code", "Cascadia Mono", "JetBrains Mono", "SF Mono", "Consolas",
         "DejaVu Sans Mono", "Menlo"],
        "monospace",
    )


def mono_font(size: float = 9.5) -> QFont:
    font = QFont(mono_font_family())
    font.setPointSizeF(size)
    font.setStyleHint(QFont.Monospace)
    return font


def palette() -> QPalette:
    pal = QPalette()
    for role, colour in (
        (QPalette.Window, BG), (QPalette.Base, SURFACE), (QPalette.AlternateBase, SURFACE_HI),
        (QPalette.Text, TEXT), (QPalette.WindowText, TEXT), (QPalette.ButtonText, TEXT),
        (QPalette.Button, SURFACE), (QPalette.Highlight, "#3a3222"),
        (QPalette.HighlightedText, TEXT), (QPalette.Link, BLUE),
        (QPalette.PlaceholderText, TEXT_FAINT), (QPalette.ToolTipBase, SURFACE_HI),
        (QPalette.ToolTipText, TEXT),
    ):
        pal.setColor(role, QColor(colour))
    return pal


def stylesheet() -> str:
    mono = mono_font_family()
    return f"""
QWidget {{ color: {TEXT}; font-size: 10.5pt; }}
QMainWindow, #Root {{ background: {BG}; }}
QToolTip {{ background: {SURFACE_HI}; color: {TEXT}; border: 1px solid {BORDER_HI};
            border-radius: 6px; padding: 5px 8px; }}

/* header */
#Header {{ background: {BG}; border-bottom: 1px solid {BORDER}; }}
#Wordmark {{ font-size: 12pt; font-weight: 600; letter-spacing: 0.3px; }}
#WordmarkSub {{ color: {TEXT_FAINT}; font-size: 9pt; }}
#Chip {{ background: {SURFACE}; border: 1px solid {BORDER}; border-radius: 15px;
         padding: 5px 12px 5px 30px; color: {TEXT_DIM}; text-align: left; }}
#Chip:hover {{ border-color: {BORDER_HI}; color: {TEXT}; background: {SURFACE_HI}; }}
#Chip:disabled {{ color: {TEXT_FAINT}; }}
#Segment {{ background: {SURFACE}; border: 1px solid {BORDER}; border-radius: 15px; }}
#SegmentButton {{ background: transparent; border: none; border-radius: 12px;
                  padding: 4px 14px; color: {TEXT_DIM}; font-weight: 500; }}
#SegmentButton:hover {{ color: {TEXT}; }}
#SegmentButton:checked {{ background: {SURFACE_HI}; color: {TEXT}; }}
#SegmentButton[danger="true"]:checked {{ background: #3a2c12; color: {ACCENT_HI}; }}

/* transcript */
QScrollArea {{ background: transparent; border: none; }}
#Transcript {{ background: {BG}; }}
QScrollBar:vertical {{ background: transparent; width: 10px; margin: 4px 2px; }}
QScrollBar::handle:vertical {{ background: {BORDER}; border-radius: 3px; min-height: 40px; }}
QScrollBar::handle:vertical:hover {{ background: {BORDER_HI}; }}
QScrollBar::add-line, QScrollBar::sub-line, QScrollBar::add-page, QScrollBar::sub-page {{
    background: none; height: 0; }}
QScrollBar:horizontal {{ height: 0; }}

#UserBubble {{ background: {SURFACE_HI}; border: 1px solid {BORDER}; border-radius: 16px; }}
#AssistantText {{ color: {TEXT}; }}
#Holding {{ color: {TEXT_FAINT}; font-style: italic; }}
#Notice {{ color: {TEXT_DIM}; font-size: 9.5pt; }}
#NoticeError {{ color: {RED}; }}

#ToolCard {{ background: {SURFACE}; border: 1px solid {BORDER}; border-radius: {RADIUS}px; }}
#ToolCard[state="waiting"] {{ border-color: #5a4418; }}
#ToolHeader {{ background: transparent; border: none; border-radius: {RADIUS}px; }}
#ToolHeader:hover {{ background: {SURFACE_HI}; }}
#ToolName {{ font-weight: 600; }}
#ToolArg {{ color: {TEXT_DIM}; font-family: "{mono}"; font-size: 9.5pt; }}
#ToolOutput {{ background: transparent; color: {TEXT_DIM}; border: none; border-top: 1px solid {BORDER};
               font-family: "{mono}"; font-size: 9.2pt; padding: 10px 14px; }}
#Pill {{ border-radius: 9px; padding: 1px 9px; font-size: 8.5pt; font-weight: 600; }}
#Pill[kind="running"] {{ background: #1c2433; color: {BLUE}; }}
#Pill[kind="ok"] {{ background: #13271d; color: {GREEN}; }}
#Pill[kind="error"] {{ background: #2e1618; color: {RED}; }}
#Pill[kind="waiting"] {{ background: #33280f; color: {ACCENT}; }}
#Pill[kind="declined"] {{ background: #22252c; color: {TEXT_DIM}; }}

#ApprovalBar {{ border-top: 1px solid {BORDER}; background: transparent; }}
#ApprovalQuestion {{ color: {TEXT}; }}
#Primary {{ background: {ACCENT}; color: {ACCENT_INK}; border: none; border-radius: 8px;
            padding: 6px 16px; font-weight: 600; }}
#Primary:hover {{ background: {ACCENT_HI}; }}
#Secondary {{ background: {SURFACE_HI}; color: {TEXT}; border: 1px solid {BORDER_HI};
              border-radius: 8px; padding: 6px 14px; }}
#Secondary:hover {{ border-color: {TEXT_FAINT}; }}
#Ghost {{ background: transparent; color: {TEXT_DIM}; border: none; padding: 6px 10px; }}
#Ghost:hover {{ color: {TEXT}; }}

/* empty state */
#Hero {{ font-size: 19pt; font-weight: 600; }}
#HeroSub {{ color: {TEXT_DIM}; }}
#Suggestion {{ background: {SURFACE}; border: 1px solid {BORDER}; border-radius: 12px;
               padding: 12px 14px; color: {TEXT_DIM}; text-align: left; }}
#Suggestion:hover {{ border-color: {BORDER_HI}; color: {TEXT}; background: {SURFACE_HI}; }}

/* composer */
#Composer {{ background: {SURFACE}; border: 1px solid {BORDER}; border-radius: 18px; }}
#Composer[focused="true"] {{ border-color: {BORDER_HI}; }}
#ComposerEdit {{ background: transparent; border: none; padding: 0; selection-background-color: #3a3222; }}
#Hint {{ color: {TEXT_FAINT}; font-size: 8.8pt; }}

/* chats dialog */
QDialog#ChatDialog {{ background: {BG}; }}
#ChatList {{ background: {SURFACE}; border: 1px solid {BORDER}; border-radius: {RADIUS}px;
             padding: 4px; outline: none; }}
#ChatList::item {{ border-radius: 9px; margin: 1px 0; }}
#ChatList::item:hover {{ background: {SURFACE_HI}; }}
#ChatList::item:selected {{ background: #262017; border: 1px solid #4a3a18; }}
#ChatTitle {{ font-weight: 600; }}
#ChatTime {{ color: {TEXT_FAINT}; font-size: 9pt; }}
#ChatPreview {{ color: {TEXT_DIM}; font-size: 9.5pt; }}
"""


def dark_title_bar(window) -> None:
    """Windows 11: dark caption, painted the same colour as the window so the
    title bar and the app read as one surface. Silently does nothing on other
    platforms or older Windows."""
    if sys.platform != "win32":
        return
    try:
        import ctypes
        from ctypes import wintypes

        hwnd = wintypes.HWND(int(window.winId()))
        dwm = ctypes.windll.dwmapi

        def attr(key: int, value: int) -> None:
            data = ctypes.c_int(value)
            dwm.DwmSetWindowAttribute(hwnd, key, ctypes.byref(data), ctypes.sizeof(data))

        attr(20, 1)  # DWMWA_USE_IMMERSIVE_DARK_MODE
        colour = BG.lstrip("#")
        r, g, b = int(colour[0:2], 16), int(colour[2:4], 16), int(colour[4:6], 16)
        attr(35, (b << 16) | (g << 8) | r)  # DWMWA_CAPTION_COLOR (COLORREF is 0x00BBGGRR)
        border = BORDER.lstrip("#")
        r, g, b = int(border[0:2], 16), int(border[2:4], 16), int(border[4:6], 16)
        attr(34, (b << 16) | (g << 8) | r)  # DWMWA_BORDER_COLOR
    except Exception:
        pass