import os
import re
import json
import sqlalchemy
from functools import wraps
from sqlalchemy.sql import select
from sqlalchemy.sql import text
from flask import Flask
from flask import render_template, send_from_directory, request, Response
from werkzeug.utils import secure_filename

app = Flask(__name__)

db_engine = {}
db_metadata = {}
parts = {}

def check_auth(username, password):
	admin_list = []
	with open('edit_admin.json', 'r') as admin:
		admin_list = json.load(admin)
	for user in admin_list:
		if username == user['username']:
			return password == user['password']

def authenticate():
	return Response('Could not verify access level. Please retry', 401, {'WWW-Authenticate' :  'Basic realm="Login Required"'})

def requires_auth(f):
	@wraps(f)
	def decorated(*args, **kwargs):
		auth = request.authorization
		if not auth or not check_auth(auth.username, auth.password):
			return authenticate()
		return f(*args, **kwargs)
	return decorated

@app.route('/parts')
def index():
    return render_template('partsearch.html')

@app.route('/parts/getpartinfo/<partID>')
def get_part_info(partID):
    s = 'select * from parts where id = :id;'
    r = db_engine.execute(text(s), id=partID)
    l = []
    for row in r:
        l.append(dict(row))
    r.close()
    return json.dumps(l[0])

@app.route('/parts/query/<filter>/<query>')
def query(filter, query):
    query = '%' + query + '%'
    filter = int(filter)
    s = 'select * from parts where '
    if filter & (1 << 1) != 0:
        s += 'LOWER(partno) like LOWER(:name) or '
    if filter & (1 << 4) != 0:
        s += 'LOWER(description) like LOWER(:name) or '
    if filter & (1 << 5) != 0:
        s += 'LOWER(notes) like LOWER(:name) or '
    s = s[:-4] + ';'
    s = text(s)
    r = db_engine.execute(s, name=query)
    l = []
    for row in r:
        l.append(dict(row))
    r.close()
    return json.dumps(l)

@app.route('/parts/getfile/<filename>')
def getfile(filename):
    if(re.match('^[\w\-_]+$', filename) == None):
        return 'No injections pls.'

    return send_from_directory('/srv/datasheets/', filename + '.pdf')

@app.route('/parts/alter/<partID>', methods=['POST'])
@requires_auth
def alter(partID):
    partID = int(partID)
    s = ''
    if partID < 0:
        # New entry
        s =  'insert into parts (block, type, partno, partnoalt, partnoalt2, description, quantity, datasheet, notes) '
        s += 'values (:block, :type, :partno, :partnoalt, :partnoalt2, :description, :quantity, :datasheet, :notes);'
        s = text(s)
        if len(request.files) != 0:
            datasheet_file = request.files['datasheet-file']
            datasheet_filename = secure_filename(datasheet_file.filename)
            i = 1
            while os.path.isfile('srv/datasheet/' + datasheet_filename):
                datasheet_filename = datasheet_filename[:-4] + str(i) + '.pdf'
                i += 1
            datasheet_file.save('/srv/datasheets/' + datasheet_filename)
        else:
            datasheet_filename = None
        r = db_engine.execute(s, block=request.form['block'],
                                 type=request.form['type'],
                                 partno=request.form['partno'],
                                 partnoalt=request.form['partnoalt'],
                                 partnoalt2=request.form['partnoalt2'],
                                 description=request.form['description'],
                                 quantity=request.form['quantity'],
                                 datasheet=datasheet_filename,
                                 notes=request.form['notes'])
    else:
        # Modify entry
        r = db_engine.execute(text('select * from parts where id=:id;'), id=partID)
        l = []
        for row in r:
            l.append(dict(row))
        r.close()
        s = 'update parts '
        s += 'set block=:block, type=:type, partno=:partno, partnoalt=:partnoalt, partnoalt2=:partnoalt2, description=:description, quantity=:quantity, datasheet=:datasheet, notes=:notes '
        if len(request.files) != 0:
            datasheet_file = request.files['datasheet-file']
            datasheet_filename = secure_filename(datasheet_file.filename)
            i = 1
            while os.path.isfile('srv/datasheet/' + datasheet_filename):
                datasheet_filename = datasheet_filename[:-4] + str(i) + '.pdf'
                i += 1
            datasheet_file.save('/srv/datasheets/' + datasheet_filename)
            if l[0]['datasheet'] != None:
                os.remove('/srv/datasheets/' + l[0]['datasheet'])
        else:
            datasheet_filename = l[0]['datasheet']
        s += 'where id=:id;'
        s = text(s)
        r = db_engine.execute(s, location_id=request.form['block'],
                                 type=request.form['type'],
                                 partno=request.form['partno'],
                                 partnoalt=request.form['partnoalt'],
                                 partnoalt2=request.form['partnoalt2'],
                                 description=request.form['description'],
                                 quantity=request.form['quantity'],
                                 datasheet=datasheet_filename,
                                 notes=request.form['notes'],
                                 id=partID)


    return '{"status":"ok"}'

@app.route('/parts/delete/<partID>')
@requires_auth
def delete(partID):
    if partID < 0:
        abort(400)
    s = text('delete from parts where id=:id;')
    r = db_engine.execute(s, id=partID)
    return '{"status":"ok"}'

def connect(user, password, db, host='localhost', port=5432):
    '''Returns a connection and a metadata object'''
    # We connect with the help of the PostgreSQL URL
    url = 'postgresql://{}:{}@{}:{}/{}'
    url = url.format(user, password, host, port, db)

    # The return value of create_engine() is our connection object
    con = sqlalchemy.create_engine(url, client_encoding='utf8')

    # We then bind the connection to MetaData()
    meta = sqlalchemy.MetaData(bind=con, reflect=True)

    return con, meta

if __name__ == '__main__':
    with open('admin.json') as f:
        postgres_credentials = json.load(f)
    db_engine, db_metadata = connect(postgres_credentials['username'], postgres_credentials['password'], 'parts_v2')
    parts = sqlalchemy.Table('parts', db_metadata)
    # Example query
    '''s = select([parts]).where(parts.c.notes != '')
    for row in db_engine.execute(s):
        print row'''
    app.run('0.0.0.0')