"""Story 路由候选 JSON：排序、summary 优先、预算降级。"""

from __future__ import annotations

import json
from datetime import datetime, timezone
from types import SimpleNamespace

from app.agents.memoir.story_route_payload import (
    build_route_candidate_json,
    build_route_candidate_rows,
    sort_stories_for_route,
    _truncate_body_for_route,
)
from app.core.config import Settings


def _story(**kwargs):
    defaults = dict(
        id="s-default",
        title="T",
        summary=None,
        canonical_markdown="",
        updated_at=None,
        chapter_links=[],
    )
    defaults.update(kwargs)
    return SimpleNamespace(**defaults)


def test_sort_has_summary_first_then_recency():
    older = _story(
        id="old",
        summary="x" * 40,
        updated_at=datetime(2020, 1, 1, tzinfo=timezone.utc),
    )
    newer = _story(
        id="new",
        summary="",
        canonical_markdown="body",
        updated_at=datetime(2025, 1, 1, tzinfo=timezone.utc),
    )
    meta = {
        "old": {"char_count": 10, "version_count": 1},
        "new": {"char_count": 20, "version_count": 2},
    }
    out = sort_stories_for_route([newer, older], meta, summary_min_chars=30)
    assert [s.id for s in out] == ["old", "new"]


def test_sort_tiebreak_version_then_char_then_id():
    t = datetime(2024, 6, 1, tzinfo=timezone.utc)
    a = _story(id="a", summary="", canonical_markdown="a", updated_at=t)
    b = _story(id="b", summary="", canonical_markdown="bb", updated_at=t)
    meta = {
        "a": {"char_count": 100, "version_count": 1},
        "b": {"char_count": 50, "version_count": 3},
    }
    out = sort_stories_for_route([a, b], meta, summary_min_chars=30)
    assert [s.id for s in out] == ["b", "a"]


def test_summary_sufficient_omits_body():
    s = _story(
        id="1",
        summary="信" * 40,
        canonical_markdown="正文" * 500,
    )
    settings = Settings()
    rows = build_route_candidate_rows(
        [s], {"1": {"char_count": 10, "version_count": 1}}, settings
    )
    assert "summary" in rows[0]
    assert "body_for_route" not in rows[0]


def test_short_summary_falls_back_to_body():
    s = _story(
        id="1",
        summary="短",
        canonical_markdown="唯一的正文用于路由",
    )
    settings = Settings()
    rows = build_route_candidate_rows(
        [s], {"1": {"char_count": 20, "version_count": 1}}, settings
    )
    assert "summary" not in rows[0]
    assert rows[0].get("body_for_route")


def test_long_body_uses_head_tail():
    md = "块" * 3000
    out = _truncate_body_for_route(
        md,
        body_max_chars=1600,
        head_chars=100,
        tail_chars=100,
    )
    assert "中间省略" in out
    assert len(out) < len(md)


def test_total_budget_downgrades_tail_rows(monkeypatch):
    settings = Settings()
    monkeypatch.setattr(settings, "story_route_candidate_total_max_chars", 800)
    monkeypatch.setattr(settings, "story_route_index_preview_chars", 40)
    stories = [
        _story(
            id="1",
            summary="",
            canonical_markdown="A" * 400,
            updated_at=datetime(2025, 1, 2, tzinfo=timezone.utc),
        ),
        _story(
            id="2",
            summary="",
            canonical_markdown="B" * 400,
            updated_at=datetime(2025, 1, 1, tzinfo=timezone.utc),
        ),
    ]
    meta = {
        "1": {"char_count": 400, "version_count": 1},
        "2": {"char_count": 400, "version_count": 1},
    }
    payload = build_route_candidate_json(stories, meta, settings)
    data = json.loads(payload)
    assert any("preview" in row and "body_for_route" not in row for row in data)


def test_json_includes_core_fields():
    s = _story(
        id="x1",
        title="标题",
        summary="y" * 40,
        updated_at=datetime(2024, 1, 1, tzinfo=timezone.utc),
    )
    settings = Settings()
    js = build_route_candidate_json(
        [s], {"x1": {"char_count": 5, "version_count": 2}}, settings
    )
    row = json.loads(js)[0]
    assert row["id"] == "x1"
    assert row["title"] == "标题"
    assert row["version_count"] == 2
    assert row["char_count"] == 5
    assert "updated_at" in row