"""
Mobile layout regression tests — run on every QA pass.

These tests check that the CSS and HTML structure required for correct
mobile rendering (375px–640px viewport widths) is intact after every change.
They are static checks (no server needed) that catch common regressions:

  - Mobile breakpoints present for key layout elements
  - Right panel slide-over markup and CSS intact
  - Profile dropdown not clipped by overflow on mobile
  - Composer footer chips scroll correctly on narrow viewports
  - Mobile sidebar navigation stays available on phones
  - No full-viewport overflow that would break scroll

Run as part of the standard test suite:
    pytest tests/test_mobile_layout.py -v
"""

import pathlib
import re

REPO = pathlib.Path(__file__).parent.parent
HTML = (REPO / "static" / "index.html").read_text(encoding="utf-8")
CSS  = (REPO / "static" / "style.css").read_text(encoding="utf-8")


# ── Mobile breakpoint rules ───────────────────────────────────────────────────

def test_mobile_breakpoint_900px_present():
    """@media(max-width:900px) must hide the right panel and show mobile-files-btn."""
    assert "@media(max-width:900px)" in CSS or "@media (max-width: 900px)" in CSS, \
        "Missing @media(max-width:900px) breakpoint in style.css"
    # Right panel should be hidden at 900px, replaced by slide-over
    assert ".rightpanel{display:none" in CSS or ".rightpanel {display:none" in CSS or \
           re.search(r'max-width:900px\).*?\.rightpanel\{display:none', CSS, re.DOTALL), \
        ".rightpanel must be display:none at max-width:900px (slide-over replaces it)"


def test_mobile_breakpoint_640px_present():
    """@media(max-width:640px) must exist for narrow phone layouts."""
    assert "@media(max-width:640px)" in CSS or "@media (max-width: 640px)" in CSS, \
        "Missing @media(max-width:640px) breakpoint in style.css"


def test_rightpanel_mobile_slide_over_css():
    """Right panel must have position:fixed slide-over CSS for mobile."""
    # At max-width:900px the rightpanel should be position:fixed, off-screen right
    assert "position:fixed" in CSS, \
        "style.css must have position:fixed for rightpanel mobile slide-over"
    assert ".rightpanel.mobile-open{right:0" in CSS or ".rightpanel.mobile-open {right:0" in CSS, \
        ".rightpanel.mobile-open must set right:0 to slide panel in from right"
    assert "right:-320px" in CSS or "right: -320px" in CSS, \
        "rightpanel must start off-screen (right:-320px) on mobile"


def test_mobile_overlay_present():
    """Mobile overlay element must exist for tap-to-close sidebar behavior."""
    assert 'id="mobileOverlay"' in HTML, \
        "#mobileOverlay element missing from index.html"
    assert "mobile-overlay" in CSS, \
        ".mobile-overlay CSS rule missing from style.css"


def test_sidebar_nav_present():
    """Sidebar top navigation tabs must be present."""
    assert 'class="sidebar-nav"' in HTML, \
        ".sidebar-nav missing from index.html"
    assert ".sidebar-nav{" in CSS or ".sidebar-nav {" in CSS, \
        ".sidebar-nav CSS rule missing from style.css"


def test_mobile_does_not_hide_sidebar_nav():
    """Phone breakpoint must keep the sidebar top navigation visible."""
    mobile_block = re.search(r'@media\(max-width:640px\)\{(.*)\n\s*\}', CSS, re.DOTALL)
    assert mobile_block, "Missing @media(max-width:640px) block in style.css"
    assert ".sidebar-nav{display:none" not in mobile_block.group(1).replace(" ", ""), \
        ".sidebar-nav must stay visible on mobile"


def test_mobile_files_button_present():
    """Mobile files toggle button (#btnWorkspacePanelToggle.workspace-toggle-btn) must be in HTML and CSS."""
    assert 'id="btnWorkspacePanelToggle"' in HTML, \
        "#btnWorkspacePanelToggle missing from index.html"
    assert "workspace-toggle-btn" in CSS, \
        ".workspace-toggle-btn CSS missing from style.css"


# ── Profile dropdown overflow ─────────────────────────────────────────────────

def test_profile_dropdown_not_clipped_by_overflow():
    """Profile dropdown must not be inside an overflow:hidden or overflow-x:auto ancestor
    without a higher z-index escape hatch.

    The topbar-chips container uses overflow-x:auto on mobile, which creates a
    stacking context that clips absolutely-positioned children. The profile dropdown
    must use position:fixed on mobile OR the topbar-chips must not clip it.
    """
    # The profile-chip wrapper must have position:relative so the dropdown can escape
    assert 'id="profileChipWrap"' in HTML, \
        "#profileChipWrap missing from index.html"
    # Profile dropdown must have a z-index high enough to clear the topbar
    assert ".profile-dropdown{" in CSS or ".profile-dropdown {" in CSS, \
        ".profile-dropdown CSS rule missing"
    # z-index must be at least 200 (topbar is z-index:10)
    m = re.search(r'\.profile-dropdown\{[^}]*z-index:(\d+)', CSS)
    if m:
        assert int(m.group(1)) >= 100, \
            f".profile-dropdown z-index {m.group(1)} is too low — must be >= 100 to clear topbar"


def test_topbar_chips_mobile_overflow():
    """topbar-chips must use overflow-x:auto on mobile for chip scrolling.

    Chips (profile, workspace, model, files) must scroll horizontally on narrow
    viewports rather than wrapping onto a second line which would break the topbar layout.
    """
    # At narrow viewport, topbar-chips should scroll
    assert "overflow-x:auto" in CSS or "overflow-x: auto" in CSS, \
        "topbar-chips must have overflow-x:auto for mobile chip scrolling"


# ── Workspace panel close ─────────────────────────────────────────────────────

def test_workspace_close_button_present():
    """Workspace panel must have a close/hide button accessible on mobile."""
    # Accept handleWorkspaceClose() (two-step close: file→browse→closed), or the
    # lower-level functions directly.  handleWorkspaceClose is preferred because
    # it dismisses a file preview first before closing the panel.
    has_close = (
        'onclick="handleWorkspaceClose()"' in HTML or
        'onclick="closeWorkspacePanel()"' in HTML or
        'onclick="toggleWorkspacePanel()"' in HTML
    )
    assert has_close, \
        "handleWorkspaceClose() or closeWorkspacePanel() must be wired to a button to close the workspace panel on mobile"


def test_toggle_mobile_files_js_defined():
    """toggleMobileFiles() must be defined in boot.js."""
    boot_js = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
    assert "function toggleMobileFiles()" in boot_js, \
        "toggleMobileFiles() missing from static/boot.js"
    assert "mobile-open" in boot_js, \
        "toggleMobileFiles() must toggle mobile-open class on the right panel"


def test_new_conversation_closes_mobile_sidebar():
    """New conversation must close the mobile drawer so the chat pane is visible immediately."""
    boot_js = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
    click_line = next((ln for ln in boot_js.splitlines() if "$('btnNewChat').onclick" in ln), "")
    assert click_line, "btnNewChat onclick handler missing from static/boot.js"
    assert "closeMobileSidebar" in click_line, \
        "btnNewChat handler must closeMobileSidebar() after creating the new session"

    shortcut_line = next((ln for ln in boot_js.splitlines() if "e.key==='k'" in ln or "e.key === 'k'" in ln), "")
    assert shortcut_line, "Cmd/Ctrl+K new chat shortcut missing from static/boot.js"
    shortcut_block = "\n".join(boot_js.splitlines()[boot_js.splitlines().index(shortcut_line):boot_js.splitlines().index(shortcut_line)+4])
    assert "closeMobileSidebar" in shortcut_block, \
        "Cmd/Ctrl+K new chat shortcut must closeMobileSidebar() after creating the new session"


# ── Viewport and scroll safety ────────────────────────────────────────────────

def test_body_overflow_hidden():
    """body must have overflow:hidden to prevent double scrollbars on mobile."""
    assert "body{" in CSS or "body {" in CSS, \
        "body rule missing from style.css"
    assert re.search(r'body\{[^}]*overflow:hidden', CSS), \
        "body must have overflow:hidden to prevent double scrollbars"


def test_flex_parents_allow_message_scroller_to_shrink():
    """The top-level flex containers must opt into min-height:0 so .messages can scroll on mobile.

    Mobile Safari/Chrome can trap scroll when a flex child with overflow:auto sits inside
    parents whose min-height remains auto. Both .layout and .main need min-height:0.
    """
    assert re.search(r'\.layout\{[^}]*min-height:0', CSS), \
        ".layout must set min-height:0 so the chat column can shrink and scroll"
    assert re.search(r'\.main\{[^}]*min-height:0', CSS), \
        ".main must set min-height:0 so .messages remains scrollable while busy"


def test_messages_touch_scrolling_hints_present():
    """The messages scroller must advertise touch-friendly scrolling behavior.

    On mobile browsers, momentum scrolling and explicit pan-y/overscroll behavior help
    prevent the chat area from feeling locked while the app body itself stays overflow:hidden.
    """
    assert re.search(r'\.messages\{[^}]*-webkit-overflow-scrolling:\s*touch', CSS), \
        ".messages must enable -webkit-overflow-scrolling:touch for mobile momentum scroll"
    assert re.search(r'\.messages\{[^}]*touch-action:\s*pan-y', CSS), \
        ".messages must set touch-action:pan-y so vertical swipe gestures scroll the transcript"
    assert re.search(r'\.messages\{[^}]*overscroll-behavior-y:\s*contain', CSS), \
        ".messages must contain vertical overscroll so the transcript keeps the gesture"


def test_100dvh_viewport_height():
    """Layout must use 100dvh (dynamic viewport height) for correct mobile sizing.

    On mobile Safari and Chrome, 100vh includes the browser chrome (address bar),
    causing content to be hidden. 100dvh accounts for the actual available height.
    """
    assert "100dvh" in CSS, \
        "style.css must use 100dvh for correct mobile viewport height (100vh hides content under address bar)"


def test_composer_touch_target_size():
    """Send button and composer inputs must have minimum 44px touch targets on mobile.

    Apple HIG and Google Material guidelines both require 44px minimum touch targets.
    """
    # Check that mobile CSS doesn't make the send button smaller than 44×44
    # We check that there's at least a min-height definition for touch targets
    assert re.search(r'(min-height|height).*44px', CSS), \
        "style.css must define 44px minimum touch targets for mobile (send button, nav buttons)"


# ── Input zoom prevention ─────────────────────────────────────────────────────

def test_composer_textarea_font_size_mobile():
    """Composer textarea must have font-size >= 16px on mobile.

    iOS Safari zooms the viewport when an input with font-size < 16px is focused,
    which breaks the layout. The composer textarea must be >= 16px at mobile widths.
    """
    # Check for 16px font-size on the textarea in a mobile breakpoint
    assert re.search(r'font-size:16px', CSS), \
        "Composer textarea must have font-size:16px at mobile widths to prevent iOS zoom-on-focus"



# ── Sidebar tabs on mobile ───────────────────────────────────────────────────

def test_profiles_sidebar_tab_present():
    """Sidebar tab strip must include Profiles."""
    assert 'class="nav-tab" data-panel="profiles"' in HTML, \
        "Sidebar nav must have a Profiles tab"


def test_mobile_bottom_nav_removed():
    """The old fixed mobile bottom nav should not be present anymore."""
    assert "mobile-bottom-nav" not in HTML, \
        "mobile-bottom-nav markup should be removed from index.html"
    assert "mobile-bottom-nav" not in CSS, \
        "mobile-bottom-nav CSS should be removed from style.css"


# ── Mobile Enter key inserts newline (PR #315, fixes #269) ───────────────────

def test_mobile_enter_newline_condition_present():
    """boot.js keydown handler must detect touch-primary devices via pointer:coarse."""
    boot_js = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
    assert "pointer:coarse" in boot_js, \
        "boot.js must use pointer:coarse media query for mobile Enter detection"


def test_mobile_enter_newline_uses_match_media():
    """boot.js must call matchMedia for pointer detection, not a hardcoded flag."""
    boot_js = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
    assert "matchMedia('(pointer:coarse)')" in boot_js or 'matchMedia("(pointer:coarse)")' in boot_js, \
        "boot.js must use matchMedia('(pointer:coarse)') for mobile detection"


def test_mobile_enter_newline_only_overrides_enter_default():
    """Mobile newline override must only apply when _sendKey is the default 'enter'."""
    boot_js = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
    # The _mobileDefault check must gate on _sendKey==='enter' so ctrl+enter users aren't affected
    assert "_sendKey===" in boot_js and "'enter'" in boot_js, \
        "Mobile newline fallback must check window._sendKey==='enter' to avoid overriding user preference"


def test_mobile_enter_does_not_affect_desktop_logic():
    """The mobile Enter override must not alter the existing else branch for desktop users."""
    boot_js = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
    # The else branch (desktop, sends on Enter without Shift) must still be present
    assert "if(!e.shiftKey){e.preventDefault();send();" in boot_js, \
        "Desktop Enter-to-send logic (else branch) must still be present in boot.js"
