import os, sys, shutil, tempfile, json
from opendm import system
from opendm import log
from opendm import context
from opendm.system import run

def filter(input_point_cloud, output_point_cloud, standard_deviation=2.5, meank=16, confidence=None, verbose=False):
    """
    Filters a point cloud
    """
    if standard_deviation <= 0 or meank <= 0:
        log.ODM_INFO("Skipping point cloud filtering")
        return

    log.ODM_INFO("Filtering point cloud (statistical, meanK {}, standard deviation {})".format(meank, standard_deviation))
    if confidence:
        log.ODM_INFO("Keeping only points with > %s confidence" % confidence)

    if not os.path.exists(input_point_cloud):
        log.ODM_ERROR("{} does not exist, cannot filter point cloud. The program will now exit.".format(input_point_cloud))
        sys.exit(1)

    filter_program = os.path.join(context.odm_modules_path, 'odm_filterpoints')
    if not os.path.exists(filter_program):
        log.ODM_WARNING("{} program not found. Will skip filtering, but this installation should be fixed.")
        shutil.copy(input_point_cloud, output_point_cloud)
        return

    filterArgs = {
      'bin': filter_program,
      'inputFile': input_point_cloud,
      'outputFile': output_point_cloud,
      'sd': standard_deviation,
      'meank': meank,
      'verbose': '-verbose' if verbose else '',
      'confidence': '-confidence %s' % confidence if confidence else '',
    }

    system.run('{bin} -inputFile {inputFile} '
         '-outputFile {outputFile} '
         '-sd {sd} '
         '-meank {meank} {confidence} {verbose} '.format(**filterArgs))

    # Remove input file, swap temp file
    if not os.path.exists(output_point_cloud):
        log.ODM_WARNING("{} not found, filtering has failed.".format(output_point_cloud))

def get_extent(input_point_cloud):
    fd, json_file = tempfile.mkstemp(suffix='.json')
    os.close(fd)
    
    # Get point cloud extent
    fallback = False

    # We know PLY files do not have --summary support
    if input_point_cloud.lower().endswith(".ply"):
        fallback = True
        run('pdal info {0} > {1}'.format(input_point_cloud, json_file))

    try:
        if not fallback:
            run('pdal info --summary {0} > {1}'.format(input_point_cloud, json_file))
    except:
        fallback = True
        run('pdal info {0} > {1}'.format(input_point_cloud, json_file))

    bounds = {}
    with open(json_file, 'r') as f:
        result = json.loads(f.read())
        
        if not fallback:
            summary = result.get('summary')
            if summary is None: raise Exception("Cannot compute summary for %s (summary key missing)" % input_point_cloud)
            bounds = summary.get('bounds')
        else:
            stats = result.get('stats')
            if stats is None: raise Exception("Cannot compute bounds for %s (stats key missing)" % input_point_cloud)
            bbox = stats.get('bbox')
            if bbox is None: raise Exception("Cannot compute bounds for %s (bbox key missing)" % input_point_cloud)
            native = bbox.get('native')
            if native is None: raise Exception("Cannot compute bounds for %s (native key missing)" % input_point_cloud)
            bounds = native.get('bbox')

        if bounds is None: raise Exception("Cannot compute bounds for %s (bounds key missing)" % input_point_cloud)
        
        if bounds.get('maxx', None) is None or \
            bounds.get('minx', None) is None or \
            bounds.get('maxy', None) is None or \
            bounds.get('miny', None) is None or \
            bounds.get('maxz', None) is None or \
            bounds.get('minz', None) is None:
            raise Exception("Cannot compute bounds for %s (invalid keys) %s" % (input_point_cloud, str(bounds)))
            
    os.remove(json_file)
    return bounds