"""
NHTSA 2024 分心驾驶类型分析
基于 IIHS/CMT 车联网数据
"""

from dataclasses import dataclass
from typing import List
import numpy as np

@dataclass
class DistractionType:
    name: str
    description: str
    nhtsa_2024_deaths: int
    iihs_telematics_share: float  # CMT 车联网占比
    police_report_share: float    # 警察报告占比
    undercount_factor: float      # 低估倍数

distraction_types = [
    DistractionType(
        name="phone_manipulation",
        description="手机操作（打字/滑动/点击）",
        nhtsa_2024_deaths=450,
        iihs_telematics_share=3.85,
        police_report_share=0.10,
        undercount_factor=38.5,
    ),
    DistractionType(
        name="phone_passive",
        description="手机被动使用（屏幕解锁但未操作，含导航）",
        nhtsa_2024_deaths=380,
        iihs_telematics_share=3.49,
        police_report_share=0.09,
        undercount_factor=38.8,
    ),
    DistractionType(
        name="phone_handheld_call",
        description="手持电话通话",
        nhtsa_2024_deaths=120,
        iihs_telematics_share=0.12,
        police_report_share=0.04,
        undercount_factor=3.0,
    ),
    DistractionType(
        name="phone_handsfree",
        description="免提通话",
        nhtsa_2024_deaths=80,
        iihs_telematics_share=0.57,
        police_report_share=0.01,
        undercount_factor=57.0,
    ),
]

print("分心类型 | CMT占比 | 警察报告 | 低估倍数")
print("--------|---------|---------|--------")
for d in distraction_types:
    print(f"{d.name} | {d.iihs_telematics_share:.2f}% | {d.police_report_share:.2f}% | {d.undercount_factor:.1f}x")

"""
DMS 分心检测：手机使用场景识别
基于 Euro NCAP 2026 DSM 协议 + IIHS 数据
"""

import numpy as np
from dataclasses import dataclass
from typing import Optional, Tuple
from enum import IntEnum

class DistractionLevel(IntEnum):
    NONE = 0          # 无分心
    LOW = 1           # 低风险（短暂视线偏离）
    MODERATE = 2      # 中风险（视线偏离 >2s）
    HIGH = 3          # 高风险（手机操作/长时间偏离）

class PhoneUseType(IntEnum):
    NONE = 0
    HANDHELD_CALL = 1    # 手持通话
    PHONE_MANIPULATION = 2  # 手机操作（打字/滑动）
    NAVIGATION = 3       # 导航（被动使用）
    HANDSFREE = 4        # 免提通话（合规）

@dataclass
class GazeMetrics:
    """视线指标"""
    gaze_x: float        # 视线水平方向（-1左 ~ +1右）
    gaze_y: float        # 视线垂直方向（-1上 ~ +1下）
    gaze_confidence: float  # 置信度 0-1
    head_yaw: float      # 头部偏航角（度）
    head_pitch: float    # 头部俯仰角（度）
    timestamp: float

@dataclass
class DistractionResult:
    level: DistractionLevel
    phone_use_type: PhoneUseType
    gaze_off_road_duration: float  # 视线离开道路时长（秒）
    confidence: float
    alert_required: bool
    alert_level: int  # 0=无, 1=一级, 2=二级

class DistractionDetector:
    """
    分心检测器
    
    Euro NCAP 2026 DSM 分心场景：
    - D-01: 视线偏离道路 ≤2s → 不警告
    - D-02: 视线偏离道路 >2s 且 <3.5s → 一级警告
    - D-03: 视线偏离道路 ≥3.5s → 二级警告
    - D-04: 手持手机至耳边 → 一级警告 ≤3s
    - D-05: 手机操作（打字/滑动） → 一级警告 ≤3s
    """
    
    def __init__(self):
        self.gaze_off_threshold = 0.3  # 视线偏离阈值（归一化）
        self.gaze_off_time_low = 2.0   # 低风险阈值（秒）
        self.gaze_off_time_moderate = 3.5  # 中风险阈值（秒）
        self.gaze_off_time_high = 5.0  # 高风险阈值（秒）
        self.phone_detection_threshold = 0.7
        
        self.gaze_history = []
        self.gaze_off_duration = 0.0
        self.last_gaze_on_road = True
        
    def update(self, metrics: GazeMetrics, 
               phone_detected: bool = False,
               phone_type: PhoneUseType = PhoneUseType.NONE) -> DistractionResult:
        """更新检测状态"""
        self.gaze_history.append(metrics)
        if len(self.gaze_history) > 300:  # 10秒 @30fps
            self.gaze_history.pop(0)
        
        # 判断视线是否在道路上
        gaze_on_road = self._is_gaze_on_road(metrics)
        
        if not gaze_on_road:
            if self.last_gaze_on_road:
                self.gaze_off_duration = 0.0
            self.gaze_off_duration += 1/30  # 假设30fps
        else:
            self.gaze_off_duration = 0.0
        
        self.last_gaze_on_road = gaze_on_road
        
        # 手机使用检测
        if phone_detected and phone_type == PhoneUseType.PHONE_MANIPULATION:
            return DistractionResult(
                level=DistractionLevel.HIGH,
                phone_use_type=phone_type,
                gaze_off_road_duration=self.gaze_off_duration,
                confidence=0.85,
                alert_required=True,
                alert_level=2,  # 二级警告
            )
        
        if phone_detected and phone_type == PhoneUseType.HANDHELD_CALL:
            return DistractionResult(
                level=DistractionLevel.MODERATE,
                phone_use_type=phone_type,
                gaze_off_road_duration=self.gaze_off_duration,
                confidence=0.80,
                alert_required=True,
                alert_level=1,  # 一级警告
            )
        
        # 视线偏离检测（Euro NCAP 场景）
        if self.gaze_off_duration >= self.gaze_off_time_high:
            return DistractionResult(
                level=DistractionLevel.HIGH,
                phone_use_type=PhoneUseType.NONE,
                gaze_off_road_duration=self.gaze_off_duration,
                confidence=0.90,
                alert_required=True,
                alert_level=2,
            )
        elif self.gaze_off_duration >= self.gaze_off_time_moderate:
            return DistractionResult(
                level=DistractionLevel.MODERATE,
                phone_use_type=PhoneUseType.NONE,
                gaze_off_road_duration=self.gaze_off_duration,
                confidence=0.85,
                alert_required=True,
                alert_level=1,
            )
        elif self.gaze_off_duration >= self.gaze_off_time_low:
            return DistractionResult(
                level=DistractionLevel.LOW,
                phone_use_type=PhoneUseType.NONE,
                gaze_off_road_duration=self.gaze_off_duration,
                confidence=0.75,
                alert_required=False,
                alert_level=0,
            )
        
        return DistractionResult(
            level=DistractionLevel.NONE,
            phone_use_type=PhoneUseType.NONE,
            gaze_off_road_duration=0.0,
            confidence=0.95,
            alert_required=False,
            alert_level=0,
        )
    
    def _is_gaze_on_road(self, metrics: GazeMetrics) -> bool:
        """判断视线是否在道路上"""
        # 道路区域：视线在水平±0.3以内，垂直-0.2到+0.3以内
        if abs(metrics.gaze_x) < self.gaze_off_threshold and \
           -0.2 < metrics.gaze_y < 0.3 and \
           metrics.gaze_confidence > 0.5:
            return True
        return False


# 测试
if __name__ == "__main__":
    detector = DistractionDetector()
    
    # 场景1：正常驾驶
    for i in range(60):
        m = GazeMetrics(gaze_x=0.0, gaze_y=0.0, gaze_confidence=0.95,
                       head_yaw=0, head_pitch=0, timestamp=i/30)
        r = detector.update(m)
    print(f"Normal: level={r.level.name}, alert={r.alert_required}")
    
    # 场景2：看手机4秒（D-03）
    for i in range(120):
        m = GazeMetrics(gaze_x=0.5, gaze_y=0.4, gaze_confidence=0.85,
                       head_yaw=20, head_pitch=-15, timestamp=i/30)
        r = detector.update(m)
    print(f"Phone gaze 4s: level={r.level.name}, duration={r.gaze_off_road_duration:.1f}s, alert=L{r.alert_level}")
    
    # 场景3：手机操作
    m = GazeMetrics(gaze_x=0.6, gaze_y=0.5, gaze_confidence=0.80,
                   head_yaw=25, head_pitch=-20, timestamp=0)
    r = detector.update(m, phone_detected=True, phone_type=PhoneUseType.PHONE_MANIPULATION)
    print(f"Phone manipulation: level={r.level.name}, alert=L{r.alert_level}")