"""Phase 108 (task 02) E2E (Playwright): the owner's exact follow-up
scenario, byte-exact on the FULL browser wire.

Story: n/a — owner bug report 2026-09-16 (TODO.md L4): "I've noticed at
least one instance where a follow-up chat is missing the first message
and response as context. So if I ask 'What is my name' and then 'What
did I just ask you?' the model responds 'This is the first question
you've asked'. But if I send a third message 'What was the previous
question' the model responds correctly … Just check if there's a bug,
there may not be."

This is LAYER 3 of the phase's three-layer wire check (D13): layers 1-2
(the trimmer + the endpoint, task 01) prove the SERVER; this file proves
the CLIENT — the localStorage ``bor.chat.v1`` record →
``conversation.slice(0, -1)`` mapping → request body → the LLM — with
the owner's exact 3-message scenario. The oracle is the phase-74
``echo my history`` marker, reused unmodified (D14): the mock answers
``history: N prior messages; last answer tail: <last 24 chars of the
most recent prior assistant message, or "none">; thinking: yes|no`` —
N = non-system messages before the LAST user message (the current
question excluded). The marker is checked BEFORE the mock's
DEFLECT_MODE branch, so the echo fires on BOTH turn branches — the
owner's questions are personal, the gate branch is irrelevant to the
pin, and no branch is asserted.

The expected tails come from the ``bor.chat.v1`` record the client
persisted (the SAME array task 02's mapping sends as ``history`` —
what the record shows IS what the model received), read AFTER each turn
persists, exactly the ``test_llm_history.py`` idiom.

Run in isolation (DB must be up: ``podman compose up -d db``):

    uv run pytest tests/e2e/test_history_wire_check.py -v --no-cov

Each test pins:

* ``test_cold_start_echo_shows_no_phantom_history`` — a FRESH
  conversation: the first message's echo shows ``0 prior messages`` /
  ``last answer tail: none`` / ``thinking: no`` — no phantom prior
  turns leak into the first turn's history block.
* ``test_owner_scenario_three_turns_carry_the_full_prior_history`` —
  the owner's exact 3 messages (turns 2-3 carry the echo marker, the
  owner's words preserved verbatim as the prefix):
  T1 ``What is my name?`` → R1 (read raw from the record); T2
  ``What did I just ask you? echo my history`` → the echo must show
  ``2 prior messages`` + R1's exact 24-char tail; T3 ``What was the
  previous question? echo my history`` → ``4 prior messages`` + R2's
  exact tail. THE regression pin for the owner's symptom: the missing-
  first-turn bug renders T2's echo as ``0 prior messages`` /
  ``last answer tail: none``.

No thinking is ever triggered (none of the owner's questions carries
the ``think out loud`` marker), so every echo reads
``thinking: no``.
"""
from __future__ import annotations

import asyncio
import json
from pathlib import Path
from threading import Thread
from typing import Any

from playwright.sync_api import Page, expect
from sqlalchemy import text

from app.config import Settings
from app.db import SessionLocal
from app.rag.importer import ImportSummary, import_sources
from app.rag.llm import LLMClient
from e2e.auth_helpers import login

REPO = Path(__file__).resolve().parents[2]
FIXTURES = REPO / "tests" / "fixtures" / "docs"
MOCK_ANSWER_MARKER = "Deterministic mock answer for E2E"
STORAGE_KEY = "bor.chat.v1"

#: The owner's exact words (TODO.md L4, verbatim). Turn 1 stays marker-
#: free (its answer R1 is the tail the turn-2 echo must reproduce);
#: turns 2-3 append the phase-74 history-echo marker AFTER the owner's
#: question, so the marker question is the owner's question plus an
#: echo suffix — the prefix travels unchanged in the user message.
T1 = "What is my name?"
T2 = "What did I just ask you? echo my history"
T3 = "What was the previous question? echo my history"


async def _import_fixtures(mock_port: int) -> ImportSummary:
    kwargs: dict[str, Any] = {"_env_file": None, "llm_base_url": f"http://127.0.0.1:{mock_port}/v1"}
    settings = Settings(**kwargs)  # pyright: ignore[reportCallIssue]
    return await import_sources([FIXTURES], LLMClient(settings))


def _run_in_thread(coro: Any) -> Any:
    """Run a coroutine on a worker thread.

    Playwright's sync API keeps an asyncio loop running on the test
    thread, so ``asyncio.run`` cannot be called directly from a test
    body.
    """
    box: dict[str, Any] = {}

    def runner() -> None:
        try:
            box["value"] = asyncio.run(coro)
        except BaseException as e:  # noqa: BLE001 — re-raised on the test thread
            box["error"] = e

    t = Thread(target=runner)
    t.start()
    t.join()
    if "error" in box:
        raise box["error"]
    return box["value"]


def _reset_db(mock_port: int, seed: bool) -> ImportSummary | None:
    """Truncate the KB (+ query log + steering notes — deterministic
    mock answers), then optionally re-import fixtures."""
    with SessionLocal() as db:
        db.execute(text("TRUNCATE chunks, documents, query_log, steering_notes"))
        db.commit()
    if not seed:
        return None
    return _run_in_thread(_import_fixtures(mock_port))


def _ask(page: Page, question: str) -> None:
    """Send one turn and wait until the answer has fully landed (the
    ``done`` event restored the Send button)."""
    page.fill("#message-input", question)
    page.click("#send-btn")
    expect(page.locator(".msg.user .bubble").last).to_contain_text(question)
    expect(page.locator(".msg.brain .bubble").last).to_contain_text(
        MOCK_ANSWER_MARKER, timeout=60_000
    )
    expect(page.locator("#send-label")).to_have_text("Send")


def _record(page: Page) -> dict[str, Any]:
    """The persisted ``bor.chat.v1`` record (the same array the client
    maps into the request body's ``history`` — what it shows IS what
    the model receives next)."""
    raw = page.evaluate(f"localStorage.getItem({STORAGE_KEY!r})")
    return json.loads(raw) if raw else {"messages": []}


def _wait_record(page: Page, n_messages: int) -> dict[str, Any]:
    """Wait until the persisted record carries ``n_messages`` turns
    (the ``done`` event's save point has landed in localStorage)."""
    page.wait_for_function(
        """([key, n]) => {
            const raw = localStorage.getItem(key);
            const rec = raw ? JSON.parse(raw) : null;
            return !!rec && rec.messages.length >= n;
        }""",
        arg=[STORAGE_KEY, n_messages],
        timeout=15_000,
    )
    return _record(page)


def test_cold_start_echo_shows_no_phantom_history(
    page: Page, app_url: str, mock_llm: int, db_ready: None
) -> None:
    summary = _reset_db(mock_llm, seed=True)
    assert summary is not None and summary.added == 13  # A9 formats (phase 47 added quadlet+j2)
    page.set_default_timeout(30_000)
    # Cold start: no restored conversation — the first question's
    # history block is empty, whatever the mock answers.
    page.add_init_script("localStorage.clear()")
    login(page, app_url, next="/")

    # The FIRST message echoes: no prior turns at all — no phantom
    # question, no phantom answer tail, no phantom thinking.
    _ask(page, "echo my history")
    bubble = page.locator(".msg.brain .bubble").last
    expect(bubble).to_contain_text("history: 0 prior messages", timeout=30_000)
    expect(bubble).to_contain_text("last answer tail: none")
    expect(bubble).to_contain_text("thinking: no")


def test_owner_scenario_three_turns_carry_the_full_prior_history(
    page: Page, app_url: str, mock_llm: int, db_ready: None
) -> None:
    summary = _reset_db(mock_llm, seed=True)
    assert summary is not None and summary.added == 13  # A9 formats (phase 47 added quadlet+j2)
    page.set_default_timeout(30_000)
    # Cold start: the ONLY prior turns any turn sees are the ones this
    # test sends — no restored conversation.
    page.add_init_script("localStorage.clear()")
    login(page, app_url, next="/")

    # Turn 1 — the owner's exact first question, marker-free. R1's raw
    # text comes from the persisted record (NOT the rendered DOM): the
    # record IS the array the client sends as `history` next turn, so
    # its tail is exactly what the model will receive.
    _ask(page, T1)
    r1 = _wait_record(page, 2)["messages"][1]
    assert r1["who"] == "brain"
    assert r1["text"], "turn 1 must have persisted a non-empty answer"
    assert "thinking" not in r1 or not r1["thinking"]  # no thinking marker in T1

    # Turn 2 — the owner's exact second question + the echo marker.
    # THE regression pin: the missing-first-turn bug the owner reported
    # renders this echo as "history: 0 prior messages" /
    # "last answer tail: none". A complete wire shows BOTH prior
    # messages (T1 + R1) and R1's exact 24-char tail.
    _ask(page, T2)
    bubble = page.locator(".msg.brain .bubble").last
    expect(bubble).to_contain_text("history: 2 prior messages", timeout=30_000)
    expect(bubble).to_contain_text(f"last answer tail: {r1['text'][-24:]}")
    expect(bubble).to_contain_text("thinking: no")
    # The persisted record carries the streamed echo — what the client
    # saved is what it sends as R2 on turn 3.
    r2 = _wait_record(page, 4)["messages"][3]
    assert r2["who"] == "brain"
    assert "history: 2 prior messages" in r2["text"]

    # Turn 3 — the owner's exact third question + the echo marker: the
    # FULL prior conversation (T1, R1, T2, R2) must reach the model —
    # 4 prior messages, the most recent answer being R2 (the echo
    # itself), tail read from the record again.
    _ask(page, T3)
    bubble = page.locator(".msg.brain .bubble").last
    expect(bubble).to_contain_text("history: 4 prior messages", timeout=30_000)
    expect(bubble).to_contain_text(f"last answer tail: {r2['text'][-24:]}")
    expect(bubble).to_contain_text("thinking: no")
    r3 = _wait_record(page, 6)["messages"][5]
    assert r3["who"] == "brain"
    assert "history: 4 prior messages" in r3["text"]