import os
import subprocess
import json
import shutil
import logging

class ConvertOBJ:
    def __init__(self, output_dir: str, center_lat: float, center_lon: float):
        self.output_dir = output_dir
        self.center_lat = center_lat
        self.center_lon = center_lon
        self.logger = logging.getLogger('UAV_Preprocess.ConvertOBJ')
        
    def convert_grid_obj(self, grid_points):
        """转换每个网格的OBJ文件为OSGB格式"""
        os.makedirs(os.path.join(self.output_dir, "osgb", "Data"), exist_ok=True)
        tile_infos = []
        
        for grid_id in grid_points.keys():
            try:
                tile_info = self._convert_single_grid(grid_id, grid_points)
                tile_infos.append(tile_info)
            except Exception as e:
                self.logger.error(f"网格 {grid_id} 转换失败: {str(e)}")
        
        self._create_merged_metadata(tile_infos)
        
    def _convert_single_grid(self, grid_id, grid_points):
        """转换单个网格的OBJ文件"""
        # 1. 构建相关路径
        grid_name = f"grid_{grid_id[0]}_{grid_id[1]}"
        project_dir = os.path.join(self.output_dir, grid_name, "project")
        texturing_dir = os.path.join(project_dir, "odm_texturing")
        opensfm_dir = os.path.join(project_dir, "opensfm")
        
        # 检查输入文件是否存在
        obj_file = os.path.join(texturing_dir, "odm_textured_model_geo.obj")
        if not os.path.exists(obj_file):
            raise FileNotFoundError(f"找不到OBJ文件: {obj_file}")
            
        # 2. 执行格式转换
        self.logger.info(f"开始转换网格 {grid_id} 的OBJ文件")
        output_osgb = os.path.join(texturing_dir, "Tile.osgb")
        
        # 计算当前网格相对于中心点的偏移
        grid_data = grid_points[grid_id]
        lats = [point['lat'] for point in grid_data]
        lons = [point['lon'] for point in grid_data]
        
        min_lat = min(lats)
        min_lon = min(lons)
        
        # 计算偏移量（米）
        offset_x = self._calculate_distance(self.center_lat, self.center_lon, self.center_lat, min_lon)
        offset_y = self._calculate_distance(self.center_lat, self.center_lon, min_lat, self.center_lon)
        
        # 修改转换命令，使用正确的参数格式
        cmd = (
            f"osgconv {obj_file} {output_osgb} "
            f"--compressed --smooth --fix-transparency "
            f"-t {offset_x},{offset_y},0 "  # 使用 -t 参数进行平移
            f"-o 0,1,0-0,0,-1"
        )
        
        try:
            subprocess.run(cmd, shell=True, check=True, cwd=texturing_dir)
        except subprocess.CalledProcessError as e:
            raise RuntimeError(f"OSGB转换失败: {str(e)}")
            
        # 3. 读取地理信息
        ref_lla_file = os.path.join(opensfm_dir, "reference_lla.json")
        with open(ref_lla_file, 'r') as f:
            ref_lla = json.load(f)
            
        # 4. 创建OSGB目录结构
        osgb_base_dir = os.path.join(self.output_dir, "osgb")
        data_dir = os.path.join(osgb_base_dir, "Data")
        tile_dir = os.path.join(data_dir, f"Tile_{grid_id[0]}_{grid_id[1]}")
        os.makedirs(tile_dir, exist_ok=True)
        
        # 5. 复制OSGB文件
        target_osgb = os.path.join(tile_dir, f"Tile_{grid_id[0]}_{grid_id[1]}.osgb")
        shutil.copy2(output_osgb, target_osgb)
        
        # 计算当前网格的边界框
        grid_data = grid_points[grid_id]
        # 假设grid_data是一个列表，每个元素都是包含lat和lon的字典
        lats = [point['lat'] for point in grid_data]
        lons = [point['lon'] for point in grid_data]
        
        min_lat = min(lats)
        max_lat = max(lats)
        min_lon = min(lons)
        max_lon = max(lons)
        
        # 计算相对于中心点的偏移
        offset_x = self._calculate_distance(self.center_lat, self.center_lon, self.center_lat, min_lon)
        offset_y = self._calculate_distance(self.center_lat, self.center_lon, min_lat, self.center_lon)
        
        tile_info = {
            'id': f"{grid_id[0]}_{grid_id[1]}",
            'bounds': {
                'min_lat': min_lat,
                'max_lat': max_lat,
                'min_lon': min_lon,
                'max_lon': max_lon
            },
            'offset': (offset_x, offset_y)
        }
        return tile_info

    def _calculate_distance(self, lat1, lon1, lat2, lon2):
        """计算两点间的距离（米）"""
        from math import sin, cos, sqrt, atan2, radians
        R = 6371000  # 地球半径（米）
        
        lat1, lon1, lat2, lon2 = map(radians, [lat1, lon1, lat2, lon2])
        dlat = lat2 - lat1
        dlon = lon2 - lon1
        
        a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
        c = 2 * atan2(sqrt(a), sqrt(1-a))
        return R * c

    def _create_merged_metadata(self, tile_infos):
        """创建合并后的metadata.xml文件"""
        metadata_content = f"""<?xml version="1.0" encoding="utf-8"?>
<ModelMetadata version="1">
    <SRS>EPSG:4326</SRS>
    <SRSOrigin>{self.center_lon},{self.center_lat},0.000000</SRSOrigin>
    <TileStructure>
        <RootNode>
            <BoundingBox>
                <MinLat>{min([t['bounds']['min_lat'] for t in tile_infos])}</MinLat>
                <MaxLat>{max([t['bounds']['max_lat'] for t in tile_infos])}</MaxLat>
                <MinLon>{min([t['bounds']['min_lon'] for t in tile_infos])}</MinLon>
                <MaxLon>{max([t['bounds']['max_lon'] for t in tile_infos])}</MaxLon>
            </BoundingBox>
            <Tiles>"""
        
        for tile in tile_infos:
            metadata_content += f"""
                    <Tile id="{tile['id']}">
                        <Offset>{tile['offset'][0]},{tile['offset'][1]},0</Offset>
                        <BoundingBox>
                            <MinLat>{tile['bounds']['min_lat']}</MinLat>
                            <MaxLat>{tile['bounds']['max_lat']}</MaxLat>
                            <MinLon>{tile['bounds']['min_lon']}</MinLon>
                            <MaxLon>{tile['bounds']['max_lon']}</MaxLon>
                        </BoundingBox>
                    </Tile>"""
        
        metadata_content += """
                </Tiles>
            </RootNode>
        </TileStructure>
        <Texture>
            <ColorSource>Visible</ColorSource>
        </Texture>
    </ModelMetadata>"""
        
        metadata_file = os.path.join(self.output_dir, "osgb", "metadata.xml")
        with open(metadata_file, 'w', encoding='utf-8') as f:
            f.write(metadata_content)