"""
Rhizi web API

@deprecated: destined to split into rz_api_rest & rz_api_websocket
"""
from datetime import datetime
from flask import Flask
from flask import escape
from flask import jsonify
from flask import make_response
from flask import redirect
from flask import render_template
from flask import request
from flask import send_from_directory
from flask import session
from flask import url_for
import flask
import json
import logging
import os
import traceback

import crypt_util
import db_controller as dbc
from db_op import DBO_add_node_set
from db_op import DBO_diff_commit__topo
from db_op import DBO_load_link_set
from db_op import DBO_match_node_id_set
from db_op import DBO_match_node_set_by_id_attribute
from db_op import DBO_rz_clone
from model.graph import Topo_Diff
from model.model import Link
from rz_api_common import __sanitize_input
from rz_api_common import sanitize_input__topo_diff
from rz_api_rest import common_resp_handle
from rz_kernel import RZ_Kernel
from rz_req_handling import make_json_response


log = logging.getLogger('rhizi')

db_ctl = None  # injected: DB controller

def __common_exec(op, on_success=common_resp_handle, on_error=common_resp_handle):
    """
    @param on_success: should return a Flask Response object
    @param on_error: should return a Flask Response object
    """
    try:
        op_ret = db_ctl.exec_op(op)
        return on_success(op_ret)
    except Exception as e:
        log.error(e.message)
        log.error(traceback.print_exc())
        return on_error(error='error occurred')

def load_node_set_by_id_attr():
    """
    load node-set by ID attribute
    
    @param id_set: list of node ids to match id attribute against
    @return: a list of nodes whose id attribute matches 'id' or
            an empty list if the requested node is not found
    @raise exception: on error
    """
    req_json = request.get_json()
    id_set = req_json['id_set']

    __sanitize_input(id_set)

    return __load_node_set_by_id_attr_common(id_set)

def __load_node_set_by_id_attr_common(id_set):
    """
    @param f_k: optional attribute filter key
    @param f_vset: possible key values to match against
    """
    op = DBO_match_node_set_by_id_attribute(id_set=id_set)
    try:
        n_set = db_ctl.exec_op(op)
        return common_resp_handle(data=n_set)
    except Exception as e:
        log.exception(e)
        return common_resp_handle(error='unable to load node with ids: {0}'.format(id_set))

def match_node_set_by_attr_filter_map(attr_filter_map):
    """
    @param attr_filter_map
    
    @return: a set of node DB id's
    """
    op = DBO_match_node_id_set(attr_filter_map)
    return __common_exec(op)

def load_link_set_by_link_ptr_set():

    def deserialize_param_set(param_json):
        l_ptr_set_raw = param_json['link_ptr_set']

        __sanitize_input(l_ptr_set_raw)

        l_ptr_set = []
        for lptr_dict in l_ptr_set_raw:
            src_id = lptr_dict.get('__src_id')
            dst_id = lptr_dict.get('__dst_id')
            l_ptr_set += [Link.Link_Ptr(src_id=src_id, dst_id=dst_id) ]

        return l_ptr_set

    l_ptr_set = deserialize_param_set(request.get_json())

    op = DBO_load_link_set.init_from_link_ptr_set(l_ptr_set)
    return __common_exec(op)

def rz_clone():

    def on_success(op_op_ret_pair):
        # serialize Topo_Diff before including in response
        for _, op_ret in op_op_ret_pair:  # discard op

            assert isinstance(op_ret, Topo_Diff), 'rz_clone: op_ret != Topo_Diff'

            topo_diff = op_ret
            topo_diff_json = topo_diff.to_json_dict()
            return common_resp_handle(topo_diff_json)

    op = DBO_rz_clone()
    return __common_exec(op, on_success=on_success)

def diff_commit__set():
    """
    commit a diff set
    """
    def sanitize_input(req):
        diff_set_dict = request.get_json()['diff_set']
        topo_diff_dict = diff_set_dict['__diff_set_topo'][0]
        topo_diff = Topo_Diff.from_json_dict(topo_diff_dict)

        sanitize_input__topo_diff(topo_diff)
        return topo_diff;

    topo_diff = sanitize_input(request)

    op = DBO_diff_commit__topo(topo_diff)
    return __common_exec(op)

def monitor__server_info():
    """
    server monitor stub
    """
    dt = datetime.now()
    return "<html><body>" + \
           "<h1>Rhizi Server v0.1</h1><p>" + \
           "date: " + dt.strftime("%Y-%m-%d") + "<br>" + \
           "time: " + dt.strftime("%H:%M:%S") + "<br>" + \
           "</p></body></html>"

def index():
    session_username = session.get('username')
    username = escape(session_username if session_username != None else "Anonymous Stranger")
    return render_template('index.html', username=username)

def login():

    def sanitize_input(req):
        req_json = request.get_json()
        u = req_json['username']
        p = req_json['password']
        return u, p

    if request.method == 'POST':
        try:
            u, p = sanitize_input(request)
        except:
            log.warn('failed to sanitize inputs. request: %s' % request)
            return make_json_response(status=401)  # return empty response
        try:
            crypt_util.validate_login(flask.current_app.rz_config, u, p)
        except Exception as e:
            # login failed
            log.warn('login: unauthorized: user: %s' % (u))
            return make_json_response(status=401)  # return empty response

        # login successful
        session['username'] = u
        log.debug('login: success: user: %s' % (u))
        return make_json_response(status=200)  # return empty response

    if request.method == 'GET':
        return render_template('login.html')

def logout():
    # remove the username from the session if it's there
    u = session.pop('username', None)
    log.debug('logout: success: user: %s' % (u))
    return redirect(url_for('login'))