"""Rail icons must sit on one vertical line, and stay there when it collapses.

Two bugs this catches:
  · "Cài đặt" sat 42px right of "Dashboard"/"Giám sát" — its QSS margin pushed
    the button in while the tree rows above start at the rail edge.
  · Collapsing re-placed the icon of every label-less button, sliding ＋ to the
    middle of the 54px rail.

Runs with the app's real stylesheet loaded. Without it the window has no
padding, margins or borders and neither bug is visible — see _apply_theme.
"""
from __future__ import annotations

import os
import sys

sys.stdout.reconfigure(encoding="utf-8", errors="replace")
from pathlib import Path

REPO = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(REPO.parent))
sys.path.insert(0, str(Path(__file__).resolve().parent))
os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")

from capture_screens import (  # noqa: E402
    _apply_theme, _freeze_schedulers, _isolate_home, _load_fonts)

TOL = 2   # px; anti-aliasing on an icon edge


def main() -> int:
    sandbox = _isolate_home()
    from PySide6.QtCore import QPoint
    from PySide6.QtWidgets import QApplication

    app = QApplication([])
    _load_fonts()
    _freeze_schedulers()
    theme_name = _apply_theme(app)

    from cowork_local.config import CONFIG_DIR
    assert str(sandbox) in str(CONFIG_DIR), f"isolation failed: {CONFIG_DIR}"

    from seed_demo_data import seed
    seed()

    from cowork_local.app import MainWindow
    from cowork_local.config import AppConfig
    from cowork_local.i18n import set_language
    from cowork_local.state import AppContext

    set_language("vi")
    win = MainWindow(AppContext(AppConfig.load()), user_name="local")
    win.resize(1400, 900)
    win.show()
    app.processEvents()
    rail = win._nav_wrap

    def ink_x(w):
        """Leftmost painted pixel of a widget, in rail coordinates."""
        img = w.grab().toImage()
        bg = img.pixelColor(w.width() - 3, 2)
        for x in range(img.width()):
            for y in range(2, img.height() - 2):
                c = img.pixelColor(x, y)
                if (abs(c.red() - bg.red()) + abs(c.green() - bg.green())
                        + abs(c.blue() - bg.blue())) > 60:
                    return w.mapTo(rail, QPoint(x, 0)).x()
        return None

    def tree_text_x(tree):
        from PySide6.QtWidgets import QStyle, QStyleOptionViewItem
        index = tree.indexFromItem(tree.topLevelItem(0), 0)
        opt = QStyleOptionViewItem()
        tree.initViewItemOption(opt)
        opt.rect = tree.visualRect(index)
        tree.itemDelegate().initStyleOption(opt, index)
        txt = tree.style().subElementRect(QStyle.SE_ItemViewItemText, opt, tree)
        return tree.mapTo(rail, QPoint(txt.left(), 0)).x()

    def btn_text_x(w):
        """Left edge of the label: first ink past the icon's gap."""
        from PySide6.QtGui import QIcon
        if not w.text():
            return None
        img = w.grab().toImage()
        bg = img.pixelColor(w.width() - 3, 2)
        ink = []
        for x in range(img.width()):
            for y in range(2, img.height() - 2):
                c = img.pixelColor(x, y)
                if (abs(c.red() - bg.red()) + abs(c.green() - bg.green())
                        + abs(c.blue() - bg.blue())) > 60:
                    ink.append(x)
                    break
        if not ink:
            return None
        for a, b in zip(ink, ink[1:]):        # first gap = icon/label spacing
            if b - a > 2:
                return w.mapTo(rail, QPoint(b, 0)).x()
        return None

    def tree_icon_x(tree):
        from PySide6.QtWidgets import QStyle, QStyleOptionViewItem
        index = tree.indexFromItem(tree.topLevelItem(0), 0)
        opt = QStyleOptionViewItem()
        tree.initViewItemOption(opt)
        opt.rect = tree.visualRect(index)
        tree.itemDelegate().initStyleOption(opt, index)
        deco = tree.style().subElementRect(
            QStyle.SE_ItemViewItemDecoration, opt, tree)
        return tree.mapTo(rail, QPoint(deco.left(), 0)).x()

    def snapshot():
        app.processEvents()
        out = {"nav rows": tree_icon_x(win.nav),
               "bottom rows": tree_icon_x(win.nav_bottom),
               "bottom rows text": tree_text_x(win.nav_bottom)}
        for label, attr in (("MENU", "_nav_toggle_btn"),
                            ("new chat", "nav_new_chat"),
                            ("settings", "_nav_settings_btn")):
            w = getattr(win, attr, None)
            if w is not None and w.isVisible():
                out[label] = ink_x(w)
                if label == "settings":
                    out["settings text"] = btn_text_x(w)
        return out

    fails = []
    for theme_name in ("dark", "light"):
        _apply_theme(app, theme_name)
        app.processEvents()
        if win._nav_collapsed:
            win._toggle_nav()
        opened = snapshot()
        win._toggle_nav()
        app.processEvents()
        closed = snapshot()
        win._toggle_nav()
        app.processEvents()
        fails += compare(theme_name, rail, opened, closed)

    print()
    for f in fails:
        print(f"FAIL  {f}")
    print("PASS  every rail icon holds its line" if not fails
          else f"{len(fails)} problem(s)")
    sys.stdout.flush()
    os._exit(1 if fails else 0)


def compare(theme_name, rail, opened, closed):
    print()
    print(f"theme={theme_name}")
    print(f"{'element':<12}{'open':>7}{'collapsed':>11}{'drift':>8}")
    fails = []
    for key in opened:
        a, b = opened[key], closed.get(key)
        drift = "-" if a is None or b is None else f"{b - a:+d}"
        print(f"{key:<12}{str(a):>7}{str(b):>11}{drift:>8}")
        if a is not None and b is not None and abs(b - a) > TOL:
            fails.append(f"{key}: icon moves {b - a:+d}px when the rail collapses")

    # Settings is a button but reads as one more row in the bottom list, so
    # both its icon and its label have to start where theirs do.
    for state, snap in (("open", opened), ("collapsed", closed)):
        for what in ("", " text"):
            ref, got = snap.get("bottom rows" + what), snap.get("settings" + what)
            if ref is not None and got is not None and abs(got - ref) > TOL:
                fails.append(f"{theme_name} {state}: settings{what} x={got} but "
                             f"the rows above it start at x={ref}")
    return fails


if __name__ == "__main__":
    raise SystemExit(main())