"""评估与统计：从自身动作日志离线复算虚拟时刻与统计量。

"演练统计"验收要求：总时间与分项耗时可独立复算 [题面/计划 §6]。
recompute_virtual_time 是回放测试与本模块共用的唯一复算实现，
客户端日志格式为 SessionLog 中 accepted 事件的 {path, request, response}。
"""

from __future__ import annotations

from ..config import CostConfig
from ..protocol.rules import CLEAR_SUCCESS
from ..protocol.timing import clear_cost, measure_cost


def recompute_virtual_time(events: list[dict],
                           cost: CostConfig = CostConfig()) -> dict:
    """从动作日志复算逐步虚拟时刻。

    events 每项形如 {path, request, response}（accepted=true）。
    返回逐步表与最终时刻；任何一步与服务器响应偏差超过容差记入 mismatches。
    """
    position = (0.0, 0.0)
    channel = 1
    virtual = 0.0
    steps, mismatches = [], []
    for index, event in enumerate(events):
        path, request = event["path"], event["request"]
        response = event["response"]
        if response.get("accepted") is not True:
            mismatches.append({"index": index, "issue": "响应未被接受"})
            continue
        if path == "/enter":
            position, channel, virtual = (0.0, 0.0), 1, response["virtual_time_s"]
        elif path == "/measure":
            pos = (request["position"]["x"], request["position"]["y"])
            predicted = measure_cost(position, pos, channel, request["channel"], cost)
            position, channel = pos, request["channel"]
            virtual += predicted.total_s
        elif path == "/clear":
            pos = (request["position"]["x"], request["position"]["y"])
            success = response.get("clear_result") == CLEAR_SUCCESS
            predicted = clear_cost(position, pos, success, cost)
            position = pos
            virtual += predicted.total_s
        elif path == "/exit":
            pass  # /exit 不推进虚拟时钟 [题面]
        else:
            mismatches.append({"index": index, "issue": f"未知路径 {path}"})
            continue
        delta = response["virtual_time_s"] - virtual
        if abs(delta) > 1e-6:
            mismatches.append({"index": index, "path": path,
                               "recomputed_s": virtual,
                               "recorded_s": response["virtual_time_s"],
                               "gap_s": delta})
        steps.append({"index": index, "path": path,
                      "predicted_s": round(virtual, 9),
                      "recorded_s": response["virtual_time_s"]})
    return {"steps": steps, "final_virtual_time_s": virtual,
            "mismatches": mismatches}


def summarize(events: list[dict]) -> dict:
    """动作计数摘要：检测/清除/移动距离等基础统计。"""
    position = (0.0, 0.0)
    measures, clears, cleared, distance_m = 0, 0, 0, 0.0
    for event in events:
        request = event["request"]
        if event["path"] in ("/measure", "/clear"):
            pos = (request["position"]["x"], request["position"]["y"])
            distance_m += ((pos[0] - position[0]) ** 2
                           + (pos[1] - position[1]) ** 2) ** 0.5
            position = pos
        if event["path"] == "/measure":
            measures += 1
        elif event["path"] == "/clear":
            clears += 1
            if event["response"].get("clear_result") == CLEAR_SUCCESS:
                cleared += 1
    return {"measures": measures, "clears": clears, "cleared": cleared,
            "distance_m": distance_m}