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"), exist_ok=True)
        for grid_id in grid_points.keys():
            try:
                self._convert_single_grid(grid_id)
            except Exception as e:
                self.logger.error(f"网格 {grid_id} 转换失败: {str(e)}")
                
        # 在所有网格处理完成后创建总的metadata.xml
        self._create_merged_metadata()
        
    def _convert_single_grid(self, grid_id):
        """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")
        
        cmd = (
            f"osgconv --compressed --smooth --fix-transparency -o 0,1,0-0,0,-1 "
            f"{obj_file} {output_osgb}"
        )
        
        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)
        
        self.logger.info(f"网格 {grid_id} 转换完成")

    def _create_merged_metadata(self):
        """创建合并后的metadata.xml文件"""
        metadata_content = f"""<?xml version="1.0" encoding="utf-8"?>
<ModelMetadata version="1">
    <!--Spatial Reference System-->
    <SRS>EPSG:4326</SRS>
    <!--Origin in Spatial Reference System-->
    <SRSOrigin>{self.center_lon},{self.center_lat},0.000000</SRSOrigin>
    <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)