"""Audit the payload of every endpoint that could load a ton of data
(phase 167, task 05, D5, LOCKED A5).

TODO L5 is one sentence: "Fix that **any any other endpoints** that could
load a ton of data." ``GET /api/docs/tree`` was the reported offender; this
script is the measured answer for the rest of the API, against the app the
operator actually runs:

    uv run python -m scripts.api_payload_audit --base-url http://localhost:8000
    # (or against the deployed app: --base-url https://brain.reeseapps.com)

It signs in through the real ``POST /api/login`` (the session cookie is the
only credential — nothing is hardcoded: ``--password`` or the
``BOR_ADMIN_PASSWORD`` the app itself reads from ``.env``), walks the
candidate read routes, and prints one row per endpoint with the IDENTITY and
the GZIP transfer size, the ratio, the wall time and a verdict against the
budget (default 256 KB — the phase's "look at it" bar; LOCKED A5: this is a
report, never a gate, so the exit code is 0 whenever the measurement
succeeded).

**Credentials are password-only on purpose.** The single-admin session is
``POST /api/login {"password": …}`` (PLAN A10) — there is no username field
to send, so there is no ``--username``; ``BOR_ADMIN_PASSWORD`` (or
``--password``) is the whole credential.

Both variants are measured on every endpoint because that is the pair the
byte-budget log line reports (``bytes=`` / ``enc=``): ``Accept-Encoding:
identity`` gives the payload the route produced, ``Accept-Encoding: gzip``
gives what the client puts on the wire (``response.num_bytes_downloaded``,
the raw bytes — ``response.content`` is already decompressed by httpx). The
routes that publish a validator (the three catalogue reads, phase 167 task
03) get one extra conditional request each: the expected answer is
``304`` with an empty body, which is the row's verdict.

Run it against the 1,000-document live-replica snapshot (the
``restore-test-db`` skill) so the numbers are the production order of
magnitude and not the fixture KB's — the corpus the run measured is printed
with the table for exactly that reason.

Exit codes: **0** the table printed (an over-budget row is a FINDING, shown
as ``LOOK``, not a failure), **2** a precondition failed — the app
unreachable, the login rejected, or no credential available.
"""
from __future__ import annotations

import argparse
import os
import sys
import time
from dataclasses import dataclass
from typing import Any

import httpx
from dotenv import load_dotenv

load_dotenv()

#: The phase's "look at it" bar (256 KB uncompressed — D5/A5). Rows over it
#: are verdict ``LOOK`` and must be fixed in the phase or carry a named
#: follow-up in ``AUDIT.md``; nothing here rejects a request.
DEFAULT_BUDGET = 262_144

#: Per-request wall-clock ceiling. A large catalogue read on the restored
#: 1,000-doc replica is fast, but a cold first query can take seconds.
DEFAULT_TIMEOUT = 60.0


@dataclass
class Row:
    """One measured endpoint."""

    label: str
    path: str
    status: int = 0
    identity_bytes: int | None = None
    identity_ms: int | None = None
    gzip_bytes: int | None = None
    gzip_ms: int | None = None
    revalidated: bool | None = None
    note: str = ""

    @property
    def ratio(self) -> str:
        """identity / gzip — how much the compression layer bought (< 1 is
        a win; ``—`` when the route did not compress)."""
        if not self.gzip_bytes or not self.identity_bytes:
            return "—"
        return f"{self.gzip_bytes / self.identity_bytes:.3f}"

    def verdict(self, budget: int) -> str:
        if self.status == 0:
            # Nothing was measured — the corpus has no such row (an empty KB,
            # no saved chats). Honest gap, not a pass and not a finding.
            return "n/a"
        if self.status == 304:
            return "304"
        if self.status != 200:
            return f"HTTP {self.status}"
        if self.revalidated:
            return "304"
        if (self.identity_bytes or 0) > budget:
            return f"LOOK (> {budget})"
        return "ok"


def build_parser() -> argparse.ArgumentParser:
    p = argparse.ArgumentParser(
        prog="python -m scripts.api_payload_audit",
        description=(
            "Measure the response size (identity AND gzip) of every "
            "candidate large-payload endpoint, against a byte budget."
        ),
    )
    p.add_argument(
        "--base-url",
        default="http://localhost:8000",
        metavar="URL",
        help="app to measure (default: http://localhost:8000)",
    )
    p.add_argument(
        "--password",
        default=None,
        metavar="PASSWORD",
        help=(
            "admin password; falls back to $BOR_ADMIN_PASSWORD (the app's "
            "own variable). The single-admin login has no username (A10)."
        ),
    )
    p.add_argument(
        "--budget",
        type=int,
        default=DEFAULT_BUDGET,
        metavar="BYTES",
        help=f"the LOOK threshold in bytes (default: {DEFAULT_BUDGET})",
    )
    p.add_argument(
        "--timeout",
        type=float,
        default=DEFAULT_TIMEOUT,
        metavar="SECONDS",
        help=f"per-request timeout (default: {DEFAULT_TIMEOUT:g})",
    )
    return p


def _fail(message: str) -> int:
    print(f"api_payload_audit: {message}", file=sys.stderr)
    return 2


def _get(client: httpx.Client, path: str, accept: str) -> tuple[int, int, int, int]:
    """GET ``path`` with an explicit ``Accept-Encoding`` →
    ``(status, body bytes, wire bytes, ms)``.

    ``body`` is the decoded payload (what the route produced); ``wire`` is
    the raw transfer, which is what the browser pays. They differ exactly
    when the response came back gzipped.
    """
    started = time.perf_counter()
    response = client.get(path, headers={"Accept-Encoding": accept})
    ms = int(round((time.perf_counter() - started) * 1000))
    return response.status_code, len(response.content), response.num_bytes_downloaded, ms


def measure(
    client: httpx.Client, label: str, path: str, *, conditional: bool = False
) -> Row:
    """One endpoint, both encodings, plus the conditional re-request on the
    routes that publish a validator (``conditional=True``)."""
    row = Row(label=label, path=path)
    row.status, row.identity_bytes, _, row.identity_ms = _get(client, path, "identity")
    gzip_status, _, wire, ms = _get(client, path, "gzip")
    row.gzip_bytes, row.gzip_ms = wire, ms
    if gzip_status != row.status:  # pragma: no cover - defensive
        row.status = gzip_status
    if conditional:
        # The ETag from a fresh unconditional GET, replayed (fetch does the
        # same thing on the second page view).
        etag = client.get(path, headers={"Accept-Encoding": "identity"}).headers.get("etag")
        if etag is None:
            row.revalidated = False
        else:
            again = client.get(
                path, headers={"Accept-Encoding": "identity", "If-None-Match": etag}
            )
            row.revalidated = again.status_code == 304 and len(again.content) == 0
    return row


def _first_folder(tree: dict[str, Any]) -> tuple[str, str] | None:
    """``(source, folder path)`` of the first folder node the depth-1 tree
    reports — a representative drill target for the node route."""
    for source in tree.get("sources", []):
        for child in source.get("children", []):
            if child.get("kind") == "folder":
                return str(source.get("name", "")), str(child.get("path", ""))
    return None


def run(args: argparse.Namespace) -> tuple[int, list[Row], list[str]]:
    """Do the whole audit; returns ``(exit code, rows, corpus lines)``."""
    password = args.password or os.environ.get("BOR_ADMIN_PASSWORD", "")
    if not password:
        return (
            _fail(
                "no admin password — pass --password or set BOR_ADMIN_PASSWORD "
                "(the app's own variable; it is never hardcoded here)"
            ),
            [],
            [],
        )

    client = httpx.Client(
        base_url=args.base_url, timeout=args.timeout, follow_redirects=False
    )
    try:
        login = client.post("/api/login", json={"password": password})
    except httpx.HTTPError as exc:
        return (
            _fail(
                f"cannot reach the app at {args.base_url} ({exc.__class__.__name__}: {exc}) "
                "— start it with `uv run uvicorn app.main:app`"
            ),
            [],
            [],
        )
    if login.status_code != 204:
        detail = ""
        try:
            detail = str(login.json().get("detail", ""))
        except Exception:  # noqa: BLE001 - a non-JSON error body is still an error
            detail = login.text[:120]
        hint = {
            401: "wrong password (BOR_ADMIN_PASSWORD of the app under test)",
            429: "rate limited (10 failed attempts / 15 min) — wait for the window",
        }.get(login.status_code, "unexpected answer from the real login route")
        return (
            _fail(
                f"login to {args.base_url} failed: HTTP {login.status_code} — "
                f"{hint} {detail}"
            ),
            [],
            [],
        )

    rows: list[Row] = []
    corpus: list[str] = []

    # --- the corpus the numbers describe (printed with the table) ---------
    docs_response = client.get("/api/docs", headers={"Accept-Encoding": "identity"})
    documents: list[dict[str, Any]] = list(docs_response.json().get("documents", []))
    by_chunks = sorted(documents, key=lambda d: int(d.get("chunks", 0)), reverse=True)
    biggest_doc = by_chunks[0] if by_chunks else None
    chunks_total = sum(int(d.get("chunks", 0)) for d in documents)
    corpus.append(f"documents={len(documents)} chunks_total={chunks_total}")

    chats: list[dict[str, Any]] = list(
        client.get("/api/chats", headers={"Accept-Encoding": "identity"}).json().get("chats", [])
    )
    biggest_chat = (
        sorted(chats, key=lambda c: int(c.get("message_count", 0)), reverse=True)[0]
        if chats
        else None
    )

    # --- the candidates ---------------------------------------------------
    rows.append(
        measure(client, "tree depth=1 (default)", "/api/docs/tree?depth=1", conditional=True)
    )
    rows.append(
        measure(client, "tree depth=8 (full)", "/api/docs/tree?depth=8", conditional=True)
    )

    depth1 = client.get(
        "/api/docs/tree?depth=1", headers={"Accept-Encoding": "identity"}
    ).json()
    folder = _first_folder(depth1)
    if folder is not None and folder[0]:
        node_path = f"/api/docs/tree/node?source={folder[0]}&path={folder[1]}&depth=1"
        rows.append(
            measure(client, f"tree node {folder[0]}/{folder[1]}", node_path, conditional=True)
        )
    else:  # the honest gap: an empty KB has no drill to measure
        rows.append(
            Row(label="tree node (drill)", path="/api/docs/tree/node", note="no folder in corpus")
        )

    rows.append(measure(client, "docs catalogue", "/api/docs", conditional=True))
    if biggest_doc is not None:
        content_path = (
            f"/api/documents/content?source={biggest_doc['source']}&path={biggest_doc['path']}"
        )
        row = measure(client, f"document content (biggest: {biggest_doc['path']})", content_path)
        body = client.get(content_path, headers={"Accept-Encoding": "identity"}).json()
        row.note = f"content field {len(str(body.get('content', '')))} chars"
        rows.append(row)
    else:
        rows.append(Row(label="document content", path="/api/documents/content", note="empty KB"))

    rows.append(measure(client, "saved chats list", "/api/chats"))
    if biggest_chat is not None:
        rows.append(
            measure(
                client,
                f"saved chat (biggest: {int(biggest_chat.get('message_count', 0))} msgs)",
                f"/api/chats/{biggest_chat['id']}",
            )
        )
    else:
        rows.append(Row(label="saved chat (one)", path="/api/chats/{id}", note="no saved chats"))

    rows.append(measure(client, "git sources", "/api/git-sources"))
    rows.append(measure(client, "suggestions", "/api/suggestions"))
    rows.append(measure(client, "sync status (polled)", "/api/sync/status"))
    rows.append(measure(client, "tokens", "/api/tokens"))
    rows.append(measure(client, "config", "/api/config"))
    rows.append(measure(client, "whoami", "/api/whoami"))
    rows.append(measure(client, "admin settings (catalogue)", "/api/admin/settings"))

    corpus.append(f"sources={len(depth1.get('sources', []))}")
    totals = depth1.get("totals") or {}
    if totals:
        corpus.append(
            f"tree totals documents={totals.get('documents')} chunks={totals.get('chunks')}"
        )
    corpus.append(f"saved_chats={len(chats)}")
    corpus.append(f"biggest_doc={biggest_doc['path'] if biggest_doc else '—'}")
    return 0, rows, corpus


def render(rows: list[Row], *, base_url: str, budget: int, corpus: list[str]) -> None:
    """The table: endpoint, identity bytes, gzip bytes, ratio, ms, verdict."""
    header: tuple[str, ...] = ("endpoint", "identity", "gzip", "ratio", "ms", "verdict")
    table: list[tuple[str, ...]] = [header]
    for row in rows:
        table.append(
            (
                row.label,
                f"{row.identity_bytes:,}" if row.identity_bytes is not None else "—",
                f"{row.gzip_bytes:,}" if row.gzip_bytes is not None else "—",
                row.ratio,
                f"{row.gzip_ms}" if row.gzip_ms is not None else "—",
                row.verdict(budget),
            )
        )
    widths = [max(len(str(r[i])) for r in table) for i in range(len(header))]

    def _line(values: tuple[Any, ...]) -> str:
        return (
            f"  {str(values[0]):<{widths[0]}}  {str(values[1]):>10}  "
            f"{str(values[2]):>10}  {str(values[3]):>{widths[3]}}  "
            f"{str(values[4]):>6}  {str(values[5])}"
        )

    print(f"api_payload_audit: base={base_url} budget={budget:,} bytes (LOOK threshold)")
    print(f"api_payload_audit: corpus {' '.join(corpus)}")
    print(_line(header))
    print(f"  {'-' * (widths[0] + 44)}")
    for row, source in zip(rows, table[1:], strict=True):
        print(_line(source))
        if row.note:
            print(f"      note: {row.note}")
    print(
        "api_payload_audit: ms is the gzip (real-client) variant; identity is the "
        "route's own bytes — the pair the ' :: api ' log line reports."
    )


def main(argv: list[str] | None = None) -> int:
    args = build_parser().parse_args(argv)
    code, rows, corpus = run(args)
    if code != 0 or not rows:
        return code
    render(rows, base_url=args.base_url, budget=args.budget, corpus=corpus)
    return 0


if __name__ == "__main__":
    sys.exit(main())