import ecto
import cv2
import pyexiv2

from opendm import log
from opendm import system
from opendm import io
from opendm import types

class ODMResizeCell(ecto.Cell):    
    def declare_params(self, params):
        pass

    def declare_io(self, params, inputs, outputs):
        inputs.declare("tree", "Struct with paths", [])
        inputs.declare("args", "The application arguments.", [])
        inputs.declare("photos", "Clusters inputs. list of ODMPhoto's", [])
        outputs.declare("photos", "Clusters output. list of ODMPhoto's", [])

    def process(self, inputs, outputs):

        log.ODM_INFO('Running ODM Resize Cell')

        # get inputs
        args = self.inputs.args
        tree = self.inputs.tree
        photos = self.inputs.photos

        if not photos:
            log.ODM_ERROR('Not enough photos in photos to resize')
            return ecto.QUIT
        
        # create working directory
        system.mkdir_p(tree.dataset_resize)

        log.ODM_DEBUG('Resizing dataset to: %s' % tree.dataset_resize)

        # check if we rerun cell or not
        rerun_cell = args['rerun'] is not None \
            and args['rerun'] == 'resize'

        # loop over photos
        for photo in photos:

            # TODO(edgar): check if resize is needed, else copy img.
            # Try to avoid oversampling!
            new_path_file = io.join_paths(tree.dataset_resize, photo.filename)

            if not io.file_exists(new_path_file) or rerun_cell:
                # open and resize image with opencv
                img = cv2.imread(photo.path_file)
                # compute new size
                max_side = max(photo.width, photo.height)
                ratio = float(args['resize_to']) / float(max_side)
                img_r = cv2.resize(img, None, fx=ratio, fy=ratio)
                # write image with opencv
                cv2.imwrite(new_path_file, img_r)
                # read metadata with pyexiv2
                old_meta = pyexiv2.ImageMetadata(photo.path_file)
                new_meta = pyexiv2.ImageMetadata(new_path_file)
                old_meta.read()
                new_meta.read()
                # copy metadata
                old_meta.copy(new_meta)
                # update metadata size
                new_meta['Exif.Photo.PixelXDimension'].value = img_r.shape[0]
                new_meta['Exif.Photo.PixelYDimension'].value = img_r.shape[1]
                new_meta.write()
                # update photos array with new values
                photo.path_file = new_path_file
                photo.width = img_r.shape[0]
                photo.height = img_r.shape[1]
                photo.update_focal()

                # log message
                log.ODM_DEBUG('Resized %s | dimensions: %s' % \
                    (photo.filename, img_r.shape))
            else:
                # log message
                log.ODM_WARNING('Already resized %s | dimensions: %s x %s' % \
                    (photo.filename, photo.width, photo.height))

        log.ODM_INFO('Resized %s images' % len(photos))
        
        # append photos to cell output
        self.outputs.photos = photos

        log.ODM_INFO('Running ODM Resize Cell - Finished')
        return ecto.OK if args['end_with'] != 'resize' else ecto.QUIT