"""T10 rollup + prefix cache 前缀稳定性测试。

验证交流文本的"恒定前缀"（version/request_id/query/meta/brief）在写入
progress/issues/decisions 后保持不变 —— 这是 llama-server --cache-reuse
命中、降低 prefill 开销的前提（D2 / 6.2 / T10）。
"""
import json

from router_system.workspace import Workspace

BRIEF = {
    "goal": "实现快排",
    "constraints": ["标准库"],
    "tags": ["code"],
    "acceptance": [{"id": "a1", "check": "可运行", "machine_checkable": True}],
    "plan": [{"id": "s1", "task": "实现", "deps": [], "done_criteria": "可运行"}],
}


def _ws():
    ws = Workspace.new("abc123def456", "写个快排")
    ws.apply_brief(BRIEF)
    return ws


def test_prefix_stable_across_writes():
    ws = _ws()
    sig0 = ws.prefix_signature()
    ws.add_progress("s1", "done", "完成", "a://s1.py")
    ws.add_issue("s1", "a://f.py#L1", "obs", "exp", "try", "ask")
    ws.add_decision("i1", "reply")
    ws.mark_round()
    ws.add_budget(input_tokens=100, output_tokens=20)
    assert ws.prefix_signature() == sig0  # 前缀不随写操作变化


def test_prefix_changes_with_brief():
    ws = _ws()
    sig = ws.prefix_signature()
    ws2 = Workspace.new("abc123def456", "写个快排")
    ws2.apply_brief({**BRIEF, "goal": "不同的目标"})
    assert ws2.prefix_signature() != sig


def test_prefix_changes_with_query():
    ws = _ws()
    sig = ws.prefix_signature()
    ws2 = Workspace.new("abc123def456", "另一个问题")
    ws2.apply_brief(BRIEF)
    assert ws2.prefix_signature() != sig


def test_rollup_keeps_prefix_stable():
    ws = _ws()
    ws.add_progress("s1", "done", "ok", "a://s1.py")
    sig_before = ws.prefix_signature()
    ws.rollup()
    assert ws.prefix_signature() == sig_before


def test_serialized_leading_is_stable():
    ws = _ws()
    head_before = _leading_json(ws)
    ws.add_progress("s1", "done", "ok", "a://s1.py")
    ws.add_issue("s1", "a://f.py#L1", "obs", "exp", "try", "ask")
    assert _leading_json(ws) == head_before


def _leading_json(ws: Workspace) -> str:
    d = ws.data
    stable = {k: d.get(k) for k in ("version", "request_id", "query", "meta", "brief")}
    return json.dumps(stable, ensure_ascii=False, sort_keys=True)