import io
import os
import re
import time
import numpy as np
import logging
import urllib.request
from flask import Blueprint, request, jsonify
from PIL import Image

from app.models.sql_factory import search_by_phash, add_phash
from app.utils.im_utils import compute_phash_int
from app.utils.file_utils import sha256_stream

sanitize_re = re.compile('[\W]+')
valid_exts = ['.gif', '.jpg', '.jpeg', '.png']

MATCH_THRESHOLD = 1
MATCH_LIMIT = 1

SIMILAR_THRESHOLD = 20
SIMILAR_LIMIT = 10

api = Blueprint('api', __name__)

@api.route('/')
def index():
  """
  API status test endpoint
  """
  return jsonify({ 'status': 'ok' })

def get_params(default_threshold=MATCH_THRESHOLD, default_limit=MATCH_LIMIT):
  try:
    threshold = int(request.form.get('threshold') or default_threshold)
    limit = int(request.form.get('limit') or default_limit)
  except:
    return None, 'param_error'
  
  # Process uploaded file
  if 'q' in request.files:
    file = request.files['q']
    fn = file.filename
    # demo client currently uploads a jpeg called 'blob'
    if fn.endswith('blob'):
      logging.debug('received a blob, assuming JPEG')
      fn = 'filename.jpg'

    basename, ext = os.path.splitext(fn)
    if ext.lower() not in valid_exts:
      return None, 'not_an_image' 
    ext = ext[1:].lower()

    raw = None
    im = Image.open(file.stream).convert('RGB')
    url = None

  # Fetch remote URL
  else:
    url = request.form.get('url')
    if not url:
      return None, 'no_image'
    basename, ext = os.path.splitext(url)
    if ext.lower() not in valid_exts:
      return None, 'not_an_image'
    ext = ext[1:].lower()

    remote_request = urllib.request.Request(url)
    remote_response = urllib.request.urlopen(remote_request)
    raw = remote_response.read()
    im = Image.open(io.BytesIO(raw)).convert('RGB')
  return (threshold, limit, url, ext, raw, im,), None

@api.route('/v1/match', methods=['POST'])
def match():
  """
  Search by uploading an image
  """
  params, error = get_params()
  if error:
    return jsonify({
      'success': False,
      'match': False,
      'added': False,
      'error': error,
    })

  threshold, limit, url, ext, raw, im = params

  start = time.time()

  phash = compute_phash_int(im)

  results = search_by_phash(phash=phash, threshold=threshold, limit=limit)

  if len(results) == 0:
    if url:
      # hash = sha256_stream(file)
      hash = sha256_stream(io.BytesIO(raw))
      add_phash(sha256=hash, phash=phash, ext=ext, url=url)
    match = False
  else:
    match = True

  logging.debug('query took {0:.2g} s.'.format(time.time() - start))

  return jsonify({
    'success': True,
    'match': match,
    'added': not match,
    'results': results,
    'timing': time.time() - start,
  })

@api.route('/v1/similar', methods=['POST'])
def similar():
  """
  Search by uploading an image
  """
  params, error = get_params(default_threshold=SIMILAR_THRESHOLD, default_limit=SIMILAR_LIMIT)
  if error:
    return jsonify({
      'success': False,
      'match': False,
      'error': error,
    })

  threshold, limit, url, ext, raw, im = params

  start = time.time()

  phash = compute_phash_int(im)
  ext = ext[1:].lower()

  results = search_by_phash(phash=phash, threshold=threshold, limit=limit)

  if len(results) == 0:
    match = False
  else:
    match = True

  logging.debug('query took {0:.2g} s.'.format(time.time() - start))

  return jsonify({
    'success': True,
    'match': match,
    'results': results,
    'timing': time.time() - start,
  })