import os
import pathlib
import io
import json
from types import SimpleNamespace
from urllib.parse import urlsplit

import pytest


REPO_ROOT = pathlib.Path(__file__).parent.parent.resolve()


def _read(path: str) -> str:
    return (REPO_ROOT / path).read_text(encoding="utf-8")


def test_terminal_is_opened_by_slash_command_not_permanent_composer_icon():
    html = _read("static/index.html")
    commands_js = _read("static/commands.js")
    sw = _read("static/sw.js")
    assert 'id="btnTerminalToggle"' not in html
    assert "name:'terminal'" in commands_js
    assert "fn:cmdTerminal" in commands_js
    assert "api('/api/workspaces')" in commands_js
    assert "await newSession()" in commands_js
    assert "toggleComposerTerminal(true)" in commands_js
    assert 'id="terminalViewport"' in html
    assert 'id="terminalSurface"' in html
    assert 'static/terminal.js' in html
    assert './static/terminal.js' in sw
    assert "xterm@5.3.0" in html


def test_terminal_surface_uses_composer_flyout_card_pattern():
    html = _read("static/index.html")
    style_css = _read("static/style.css")

    flyout = html.split('<div class="composer-flyout">', 1)[1].split('<div class="queue-pill-outer">', 1)[0]
    assert 'id="composerTerminalPanel"' in flyout
    assert 'class="composer-terminal-inner"' in flyout
    assert 'id="composerTerminalDock"' in flyout
    assert 'id="terminalResizeHandle"' in flyout
    assert 'id="composerTerminalPanel"' not in html.split('<div class="queue-pill-outer">', 1)[1]
    assert ".composer-terminal-panel{position:absolute" in style_css
    assert "bottom:-24px" in style_css
    assert "width:min(calc(100% - 64px),720px)" in style_css
    assert ".composer-wrap.terminal-dock-visible .composer-flyout{z-index:4" in style_css
    assert ".composer-terminal-panel.is-collapsed{bottom:-2px;width:min(calc(100% - 112px),560px);overflow:visible;z-index:4" in style_css
    assert ".composer-terminal-panel.is-expanding-from-dock .composer-terminal-inner{transition:opacity .18s ease" in style_css
    assert ".messages.terminal-expanding-from-dock{transition:none!important" in style_css
    assert ".composer-terminal-dock{min-height:42px" in style_css
    assert ".composer-terminal-inner{height:var(--composer-terminal-height,260px)" in style_css
    assert "transform:translateY(100%)" in style_css


def test_terminal_uses_controlled_desktop_resize_handle():
    html = _read("static/index.html")
    style_css = _read("static/style.css")
    terminal_js = _read("static/terminal.js")

    assert 'class="composer-terminal-resize-handle"' in html
    assert 'role="separator"' in html
    assert 'aria-orientation="horizontal"' in html
    terminal_inner_rule = style_css.split(".composer-terminal-inner{", 1)[1].split("}", 1)[0]
    assert "resize:" not in terminal_inner_rule
    assert "cursor:ns-resize" in style_css
    assert "const TERMINAL_HEIGHT_DEFAULT=260" in terminal_js
    assert "const TERMINAL_HEIGHT_MIN=180" in terminal_js
    assert "const TERMINAL_HEIGHT_MAX=520" in terminal_js
    assert "max:Math.max(min,Math.min(hardMax,maxByViewport))" in terminal_js


def test_terminal_resize_path_refits_backend_and_transcript_space():
    terminal_js = _read("static/terminal.js")

    assert "function _applyTerminalHeight" in terminal_js
    apply_block = terminal_js.split("function _applyTerminalHeight", 1)[1].split("function _resetTerminalHeightForViewport", 1)[0]
    assert "_fitTerminal();" in apply_block
    assert "_syncTerminalTranscriptSpace(true);" in apply_block
    assert "function _moveTerminalHeightResize" in terminal_js
    assert "_applyTerminalHeight(TERMINAL_UI.resizeStartHeight+(TERMINAL_UI.resizeStartY-ev.clientY))" in terminal_js
    assert "handle.addEventListener('pointerdown',_startTerminalHeightResize)" in terminal_js
    assert "handle.addEventListener('pointermove',_moveTerminalHeightResize)" in terminal_js
    assert "clearTimeout(TERMINAL_UI.resizeTimer)" in terminal_js
    assert "api('/api/terminal/resize'" in terminal_js


def test_terminal_open_reserves_transcript_space():
    style_css = _read("static/style.css")
    terminal_js = _read("static/terminal.js")

    assert ".messages.terminal-open{padding-bottom:var(--terminal-card-height" in style_css
    assert ".messages.terminal-collapsed{padding-bottom:var(--terminal-dock-height" in style_css
    assert "scroll-padding-bottom:var(--terminal-card-height" in style_css
    assert "classList.add('terminal-open')" in terminal_js
    assert "classList.add('terminal-collapsed')" in terminal_js
    assert "classList.remove('terminal-open')" in terminal_js
    assert "classList.remove('terminal-collapsed')" in terminal_js
    assert "messages.style.setProperty('--terminal-card-height'" in terminal_js
    assert "messages.style.setProperty('--terminal-dock-height'" in terminal_js
    assert "messages.style.removeProperty('--terminal-card-height')" in terminal_js
    assert "messages.style.removeProperty('--terminal-dock-height')" in terminal_js
    assert "function _terminalIsMessagesNearBottom" in terminal_js
    assert "scrollToBottom" in terminal_js


def test_terminal_initial_open_settles_transcript_space_before_reveal():
    terminal_js = _read("static/terminal.js")

    open_block = terminal_js.split("async function toggleComposerTerminal", 1)[1].split("function collapseComposerTerminal", 1)[0]
    assert "messages.classList.add('terminal-expanding-from-dock')" in open_block
    assert "_syncTerminalTranscriptSpace(true,{immediate:true});" in open_block
    assert "void messages.offsetHeight;" in open_block
    assert "panel.classList.add('is-open')" in open_block
    assert "messages.classList.remove('terminal-expanding-from-dock')" in open_block
    assert open_block.index("_syncTerminalTranscriptSpace(true,{immediate:true});") < open_block.index("panel.classList.add('is-open')")
    assert open_block.index("void messages.offsetHeight;") < open_block.index("panel.classList.add('is-open')")


def test_terminal_collapsed_state_preserves_pty_and_output_surface():
    html = _read("static/index.html")
    terminal_js = _read("static/terminal.js")

    assert 'id="btnTerminalCollapse"' in html
    assert 'onclick="collapseComposerTerminal()"' in html
    assert 'id="btnTerminalExpand"' in html
    assert 'onclick="expandComposerTerminal()"' in html
    assert 'id="btnTerminalDockClose"' in html
    assert 'onclick="closeComposerTerminal()"' in html
    assert "collapsed:false" in terminal_js
    collapse_block = terminal_js.split("function collapseComposerTerminal", 1)[1].split("function expandComposerTerminal", 1)[0]
    assert "api('/api/terminal/close'" not in collapse_block
    assert "_disposeXterm" not in collapse_block
    assert "_setTerminalChromeState('collapsed')" in collapse_block
    assert "composerWrap.classList.toggle('terminal-dock-visible',collapsed)" in terminal_js
    expand_block = terminal_js.split("function expandComposerTerminal", 1)[1].split("function _disposeXterm", 1)[0]
    assert "_setTerminalChromeState('expanded')" in expand_block
    assert "panel.classList.add('is-expanding-from-dock')" in expand_block
    assert "panel.classList.remove('is-expanding-from-dock')" in expand_block
    assert "messages.classList.add('terminal-expanding-from-dock')" in expand_block
    assert "messages.classList.remove('terminal-expanding-from-dock')" in expand_block
    assert "_syncTerminalTranscriptSpace(true,{immediate:true});" in expand_block
    assert "void messages.offsetHeight;" in expand_block
    assert expand_block.index("_syncTerminalTranscriptSpace(true,{immediate:true});") < expand_block.index("_setTerminalChromeState('expanded')")
    assert expand_block.index("void messages.offsetHeight;") < expand_block.index("_setTerminalChromeState('expanded')")
    assert "_resetTerminalHeightForViewport();" in expand_block
    assert "focusComposerTerminalInput();" in expand_block
    close_block = terminal_js.split("async function closeComposerTerminal", 1)[1].split("async function restartComposerTerminal", 1)[0]
    assert "api('/api/terminal/close'" in close_block
    assert "_disposeXterm();" in close_block


def test_terminal_slash_command_expands_existing_collapsed_terminal():
    commands_js = _read("static/commands.js")
    terminal_js = _read("static/terminal.js")

    assert "await toggleComposerTerminal(true)" in commands_js
    toggle_block = terminal_js.split("async function toggleComposerTerminal", 1)[1].split("function collapseComposerTerminal", 1)[0]
    assert "if(TERMINAL_UI.open)" in toggle_block
    assert "if(TERMINAL_UI.collapsed)expandComposerTerminal();" in toggle_block
    assert "else focusComposerTerminalInput();" in toggle_block


def test_terminal_slash_command_preflights_remote_backend_before_session_create():
    commands_js = _read("static/commands.js")

    cmd_block = commands_js.split("async function cmdTerminal", 1)[1].split("async function cmdNew", 1)[0]
    assert "api('/api/workspaces')" in cmd_block
    assert "syncTerminalBackendState(data)" in cmd_block
    assert "data&&data.terminal_remote_backend" in cmd_block
    assert "_terminalRemoteBackendUnsupportedMessage" in cmd_block
    # #6022: the auto-mint passes explicit worktree:false so the config
    # default can't leak a worktree from opening the terminal.
    assert cmd_block.index("data&&data.terminal_remote_backend") < cmd_block.index("await newSession(false, {worktree: false})")


def test_terminal_v1_does_not_expose_send_to_chat_action():
    html = _read("static/index.html")
    terminal_js = _read("static/terminal.js")
    combined = html + terminal_js
    assert "Send latest result to chat" not in combined
    assert "send latest result" not in combined.lower()
    assert "Send to chat" not in combined


def test_terminal_ui_handles_shell_close_commands():
    terminal_js = _read("static/terminal.js")

    assert "function _isTerminalCloseCommand" in terminal_js
    for command in ("exit", "quit", "logout", "close"):
        assert f"'{command}'" in terminal_js
    assert "closeComposerTerminal();" in terminal_js


def test_terminal_restart_ignores_stale_sse_events():
    terminal_js = _read("static/terminal.js")

    assert "if(TERMINAL_UI.source!==source)return;" in terminal_js
    assert "async function restartComposerTerminal" in terminal_js
    restart_block = terminal_js.split("async function restartComposerTerminal", 1)[1].split("function clearComposerTerminal", 1)[0]
    assert "TERMINAL_UI.source.close()" in restart_block
    assert "TERMINAL_UI.source=null" in restart_block


def test_terminal_routes_are_registered():
    routes = _read("api/routes.py")
    for path in (
        "/api/terminal/start",
        "/api/terminal/input",
        "/api/terminal/output",
        "/api/terminal/resize",
        "/api/terminal/close",
    ):
        assert path in routes


def test_terminal_process_does_not_mutate_global_terminal_cwd(tmp_path, monkeypatch):
    from api.terminal import close_terminal, start_terminal

    if os.name == "nt":
        pytest.skip("Embedded terminal PTY startup is not supported on Windows")

    monkeypatch.delenv("TERMINAL_CWD", raising=False)
    sid = "test-terminal-env"
    term = start_terminal(sid, tmp_path, rows=8, cols=40, restart=True)
    try:
        assert term.workspace == str(tmp_path.resolve())
        assert os.environ.get("TERMINAL_CWD") is None
    finally:
        close_terminal(sid)


def test_terminal_output_preserves_control_sequences_for_xterm():
    import codecs
    from api.terminal import _decode_terminal_output

    raw = "\x1b[?2004h$ \x1b[32mhello\x1b[0m\n"
    decoder = codecs.getincrementaldecoder("utf-8")("replace")
    assert _decode_terminal_output(decoder, raw.encode()) == raw


def test_terminal_xterm_theme_follows_appearance_tokens():
    terminal_js = _read("static/terminal.js")
    style_css = _read("static/style.css")

    assert "function _terminalTheme" in terminal_js
    assert "_terminalCssVar('--code-bg'" in terminal_js
    assert "_terminalCssVar('--pre-text'" in terminal_js
    assert "syncComposerTerminalAppearance" in terminal_js
    assert "attributeFilter:['class','data-skin','style']" in terminal_js
    assert "background:var(--code-bg)" in style_css
    assert "color:var(--pre-text)" in style_css


def test_terminal_button_and_start_path_respect_remote_backend_guard():
    terminal_js = _read("static/terminal.js")

    sync_block = terminal_js.split("function syncTerminalButton", 1)[1].split("function focusComposerTerminalInput", 1)[0]
    start_block = terminal_js.split("async function _startComposerTerminal", 1)[1].split("async function toggleComposerTerminal", 1)[0]
    assert "function syncTerminalBackendState" in terminal_js
    assert "function _terminalRemoteBackendUnsupportedMessage" in terminal_js
    assert "toggle.disabled=!hasWorkspace||remoteBackend;" in sync_block
    assert "_terminalRemoteBackendUnsupportedMessage()" in sync_block
    assert "if(S.terminalRemoteBackend)" in start_block
    assert "showToast(_terminalRemoteBackendUnsupportedMessage(),3200,'warning');" in start_block
    assert "payload&&payload.error==='remote_terminal_backend_unsupported'" in terminal_js


class _RouteHandler:
    def __init__(self):
        self.headers = {}
        # Real terminal requests come from a same-host browser; present as a
        # genuine loopback client so the embedded-terminal local-origin gate
        # (CVD #3 / test_cvd3_terminal_local_origin_gate.py) admits the request
        # and these tests exercise the terminal logic they target.
        self.client_address = ("127.0.0.1", 12345)
        self.wfile = io.BytesIO()
        self.responses = []

    def send_response(self, status):
        self.responses.append(status)

    def send_header(self, _name, _value):
        pass

    def end_headers(self):
        pass


def test_workspaces_route_exposes_terminal_remote_backend_flag(monkeypatch):
    import api.routes as routes

    monkeypatch.setattr(
        routes,
        "load_workspaces",
        lambda: [{"path": "/tmp/project", "name": "Project"}],
    )
    monkeypatch.setattr(routes, "get_last_workspace", lambda: "/tmp/project")
    monkeypatch.setattr(routes, "get_config", lambda: {"terminal": {"backend": "ssh"}})

    handler = _RouteHandler()
    routes.handle_get(handler, urlsplit("/api/workspaces"))
    payload = json.loads(handler.wfile.getvalue().decode("utf-8"))

    assert handler.responses == [200]
    assert payload["terminal_remote_backend"] is True
    assert payload["workspaces"][0]["path"] == "/tmp/project"
    assert payload["last"] == "/tmp/project"


def test_terminal_start_rejects_remote_backend_with_stale_workspace_before_local_validation(monkeypatch):
    import api.routes as routes

    monkeypatch.setattr(
        routes,
        "get_session",
        lambda sid: SimpleNamespace(
            session_id=sid,
            workspace="/Users/other/projects/stale-remote-workspace",
        ),
    )
    monkeypatch.setattr(
        routes,
        "get_config",
        lambda: {"terminal": {"backend": "docker", "cwd": "/Users/joeyshiue"}},
    )

    handler = _RouteHandler()
    routes._handle_terminal_start(
        handler,
        {"session_id": "session-1", "rows": 24, "cols": 80, "restart": False},
    )
    payload = json.loads(handler.wfile.getvalue().decode("utf-8"))

    assert handler.responses == [400]
    assert payload == {
        "error": "remote_terminal_backend_unsupported",
        "message": "Embedded terminal is only supported for local terminal backends.",
    }