"""
Issue #5545 three-panel desktop layout regression checks.

These tests stay source-level so they can verify the declared CSS contract
without needing a browser or rendered layout.
"""

import pathlib
import re

REPO = pathlib.Path(__file__).parent.parent
CSS = (REPO / "static" / "style.css").read_text(encoding="utf-8")
BOOT_JS = (REPO / "static" / "boot.js").read_text(encoding="utf-8")


def _media_blocks(kind):
    pattern = re.compile(rf"@media\s*\(\s*{kind}\s*:\s*(\d+)px\s*\)\s*\{{")
    blocks = []
    for match in pattern.finditer(CSS):
        width_px = int(match.group(1))
        open_brace = match.end() - 1
        depth = 0
        for idx in range(open_brace, len(CSS)):
            if CSS[idx] == "{":
                depth += 1
            elif CSS[idx] == "}":
                depth -= 1
                if depth == 0:
                    blocks.append((width_px, CSS[open_brace + 1:idx]))
                    break
    return blocks


def _normalize_css(css):
    return re.sub(r"\s+", "", css)


def _media_block(kind, width_px, needle):
    normalized_needle = _normalize_css(needle)
    for current_width, block in _media_blocks(kind):
        if current_width == width_px and normalized_needle in _normalize_css(block):
            return block
    raise AssertionError(f"Missing @media({kind}:{width_px}px) block containing {needle!r}")


def _strip_css_comments(css):
    return re.sub(r"/\*.*?\*/", "", css, flags=re.DOTALL)


def _rule_body(css, selector):
    for match in re.finditer(r"([^{}]+)\{([^{}]*)\}", _strip_css_comments(css)):
        selectors = {part.strip() for part in match.group(1).split(",")}
        if selector in selectors:
            return match.group(2)
    raise AssertionError(f"Missing CSS rule for {selector}")


def _declarations(rule_body):
    declarations = {}
    for item in rule_body.split(";"):
        if ":" not in item:
            continue
        prop, value = item.split(":", 1)
        declarations[prop.strip()] = re.sub(r"\s+", " ", value.strip())
    return declarations


def test_desktop_three_panel_contract_gives_main_readable_floor():
    desktop = _media_block("min-width", 901, ".main{flex:1 1 420px;min-width:420px;}")
    main = _declarations(_rule_body(desktop, ".main"))

    assert main.get("flex") == "1 1 420px"
    assert main.get("min-width") == "420px"


def test_desktop_side_rails_can_shrink_to_resize_minima():
    desktop = _media_block("min-width", 901, ".sidebar{flex-shrink:1;min-width:180px;}")
    sidebar = _declarations(_rule_body(desktop, ".sidebar"))
    rightpanel = _declarations(_rule_body(desktop, ".rightpanel"))
    closed_rightpanel = _declarations(
        _rule_body(desktop, 'html[data-workspace-panel="closed"] .rightpanel')
    )
    collapsed_rightpanel = _declarations(
        _rule_body(desktop, ".layout.workspace-panel-collapsed .rightpanel")
    )

    assert re.search(r"\bSIDEBAR_MIN\s*=\s*180\b", BOOT_JS)
    assert re.search(r"\bPANEL_MIN\s*=\s*180\b", BOOT_JS)
    assert sidebar.get("flex-shrink") == "1"
    assert sidebar.get("min-width") == "180px"
    assert rightpanel.get("flex-shrink") == "1"
    assert rightpanel.get("min-width") == "180px"
    assert closed_rightpanel.get("width") == "0 !important"
    assert closed_rightpanel.get("min-width") == "0 !important"
    assert collapsed_rightpanel.get("width") == "0 !important"
    assert collapsed_rightpanel.get("min-width") == "0 !important"


def test_compact_breakpoint_900px_remains_hidden_right_panel_boundary():
    assert "@media(max-width:900px)" in CSS or "@media (max-width: 900px)" in CSS

    compact = _media_block("max-width", 900, ".rightpanel{display:none}")
    rightpanel = _declarations(_rule_body(compact, ".rightpanel"))
    workspace_toggle = _declarations(_rule_body(compact, ".workspace-toggle-btn"))
    mobile_files = _declarations(_rule_body(compact, ".mobile-files-btn"))

    assert rightpanel.get("display") == "none"
    assert workspace_toggle.get("display") == "inline-flex!important"
    assert mobile_files.get("display") == "inline-flex!important"


def test_mobile_slide_over_breakpoint_640px_remains_intact():
    assert "@media(max-width:640px)" in CSS or "@media (max-width: 640px)" in CSS

    mobile = _media_block("max-width", 640, ".rightpanel.mobile-open")
    rightpanel = _declarations(_rule_body(mobile, ".rightpanel"))
    rightpanel_open = _declarations(_rule_body(mobile, ".rightpanel.mobile-open"))

    assert rightpanel.get("display") == "flex!important"
    assert rightpanel.get("position") == "fixed"
    assert rightpanel.get("right") == "calc(-1 * var(--mobile-rightpanel-width))!important"
    assert rightpanel.get("width") == "var(--mobile-rightpanel-width)!important"
    assert rightpanel.get("box-shadow") == "none!important"
    assert rightpanel_open.get("right") == "0!important"


def test_no_unmatched_desktop_hide_breakpoint_above_900():
    hidden_widths = []
    for width_px, block in _media_blocks("max-width"):
        if re.search(r"\.rightpanel\s*\{\s*display\s*:\s*none", block):
            hidden_widths.append(width_px)

    assert 900 in hidden_widths
    assert all(width_px <= 900 for width_px in hidden_widths)