import os
import time
import math
import json

import jwt
from flask import Blueprint, request, jsonify, make_response, g
from bcrypt import hashpw, gensalt, checkpw
from functools import wraps

from utils import pgclass, setting_loader, logger
from utils.misc import error
from utils.dbhelper import db, solo_article_fetcher, multi_article_fetcher, solo_file_fetcher, solo_article_remover
from utils.platform_consts import PLIST, PLIST_ROOT

admin = Blueprint("admin", __name__)

# jwt = {"id":user.id, "user":user.user, "exp":time.time}

# auth decorator
def role_required(permreq: list):
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            # get data 嘗試解碼jwt
            key = os.getenv("JWT_KEY", None)
            jwtsession = request.cookies.get("token", None)
            if jwtsession == None: return error("You do not have permission to view this page."), 401
            jwtsession = str(jwtsession)
            try: jwtdata = jwt.decode(jwt = jwtsession, key = key, algorithms = ["HS256"])
            except jwt.exceptions.ExpiredSignatureError: return error("Token expired!"), 401
            except jwt.exceptions.DecodeError: return error("Invalid token!"), 401
            if "id" not in jwtdata or "user" not in jwtdata: return error("Invalid token!"), 401
            
            # db 驗證帳號是否正確
            table = pgclass.SQLuser
            with db.getsession() as session:
                res = session.query(table).filter(table.user == jwtdata["user"], table.id == jwtdata["id"]).first()
            if res is None: return error("You do not have permission to view this page."), 401

            # permission check 確保用戶有此路徑要求的權限 並且權限名稱皆合法
            permissionList = list(set(res.permission))
            for p in permissionList: # 檢查用戶JWT是否有不合法的權限名稱
                if p not in PLIST_ROOT: return error("The user has invalid permission."), 402
            for p in list(set(permreq)):
                if p not in permissionList: return error("You do not have permission to view this page."), 402

            # return
            g.opuser = res
            return f(*args, **kwargs)
        return decorated_function
    return decorator

# login
@admin.route("/login", methods=["POST"])
def login():
    # args
    if "username" not in request.json or "password" not in request.json: return error("Arguments error"), 400
    username = str(request.json["username"])
    password = str(request.json["password"])

    # variables
    settings = setting_loader.loadset()
    exptime = int(settings["JWT_Valid_Time"])

    # db
    table = pgclass.SQLuser
    with db.getsession() as session: u = session.query(table).filter(table.user==username).first()
    # auth
    if u is None: return error("Login Failed"), 401 # 找不到用戶
    if not checkpw(password.encode("utf-8"), u.password.encode("utf-8")): return error("Login Failed"), 401 # 密碼沒法跟hash對上
    
    # jwt
    key = os.getenv("JWT_KEY", None)
    if key is None: return error("JWT_KEY error"), 500
    jwtdata = {"id": u.id, "user":username, "exp":int(math.floor(time.time() + exptime))}
    jwtdata = jwt.encode(payload = jwtdata, key = str(key), algorithm = "HS256")

    # logger
    logger.logger("login", "User:%s logined"%username)

    # cookie
    r = make_response("Access Granted")
    r.set_cookie("token", jwtdata)
    return r, 200

@admin.route("me", methods=["GET"])
@role_required([])
def user_me():
    opuser = g.opuser
    return jsonify({"id":opuser.id, "user":opuser.user, "permission":opuser.permission}), 200

####################
#     User Area    #
####################
# list / get / add / delete
@admin.route("/user/list", methods={"GET"})
@role_required([])
def user_list():
    table = pgclass.SQLuser
    with db.getsession() as session: users = session.query(table).all()
    res = [ {"id":u.id, "user":u.user, "permission":u.permission} for u in users ]
    return jsonify(res), 200

@admin.route("/user/<int:id>", methods=["GET"])
@role_required([])
def user_get(id:int):
    table = pgclass.SQLuser
    with db.getsession() as session: u = session.query(table).filter(table.id==int(id)).first()
    if u is None: return error("User not found"), 404
    return jsonify({"id":u.id, "user":u.user, "permission":u.permission}), 200

@admin.route("/user/<int:id>", methods=["DELETE"])
@role_required(["usermgr"])
def user_del(id:int):
    # db 
    table = pgclass.SQLuser

    with db.getsession() as session:
        opuser = g.opuser # user who requested

        # check root
        tguser = session.query(table).filter(table.id==int(id)).first()
        if tguser is None: return error("User is not exist"), 400
        if tguser.user == "root": return error("You cannot delete user:root"), 400
    
        # delete
        session.delete(tguser)
        session.commit()

        logger.logger("user.delete", "User:%s deleted an user:%s"%(opuser.user, tguser.user)) # logger
    return jsonify({"result":"OK"}), 200

@admin.route("/user", methods=["POST"])
@role_required(["usermgr"])
def user_add():
    # db 
    table = pgclass.SQLuser
    with db.getsession() as session:
        # user who requested
        opuser = g.opuser
        
        # payload
        if "username" not in request.json or "password" not in request.json or \
                "permission" not in request.json or not(isinstance(request.json["permission"], list)): 
            return error("Arguments error"), 400
        username = str(request.json["username"])
        password = str(request.json["password"])
        permission = list(set([ str(p) for p in list(request.json["permission"]) ]))
        # check username and password
        if username == None or len(username) == 0 or password is None or len(password) == 0: 
            return error("Invalid Username or Password!"), 400
        # check permission list
        for p in permission:
            if p not in PLIST: return error("Invalid Permission"), 400 # 如果添加的權限名稱不合法
            if p not in opuser.permission: return error("You don't have the permission: %s"%p), 402 # 如果用戶本身不具有相同權限

        # add
        users = session.query(table).filter(table.user==username).first()
        if users is None: # check whether the user already exist
            pwhash = hashpw(password.encode("utf-8"), gensalt()).decode("utf-8")
            session.add(table(user=username, password=pwhash, permission=permission))
            session.commit()
            logger.logger("user.create", "User:%s created a new user:%s"%(opuser.user, username)) # logger
            return jsonify({"user":username, "permission":permission}), 200
        else:
            return error("User already exist!"), 400

####################
#   Article Area   #
####################
# list / get / pend / delete / fileget

@admin.route("/article/file/<int:id>", methods = ["GET"])
@role_required(["article.read"])
def article_fileget(id:int):
    resp, code = solo_file_fetcher("admin", id)
    return resp, code

@admin.route('/article/list', methods = ["GET"])
@role_required(["article.read"])
def article_list():
    res, code = multi_article_fetcher("admin", request.args.get("start"), request.args.get("count"))
    return res, code

@admin.route("/article/<int:id>", methods=["GET"])
@role_required(["article.read"])
def article_read(id:int):
    res, code = solo_article_fetcher("admin", id)
    return jsonify(res), code

@admin.route("/article/<int:id>", methods=["DELETE"])
@role_required(["article.del"])
def article_del(id:int):
    opuser = g.opuser

    result, code = solo_article_remover("admin", id=id)
    if "error" in result: return jsonify(result), code

    logger.logger("article.delete", "User:%s deleted post (id=%d with comments %s): last_status=%s"%(opuser.user, result["id"], result["rcl"], result["mark"]))
    return jsonify({"result":"OK"}), 200

@admin.route("/article/<int:id>", methods=["PUT"])
@role_required(["article.pend"])
def article_pend(id:int):
    # db
    table = pgclass.SQLarticle
    with db.getsession() as session:
        # 確保文章存在
        res = session.query(table).filter(table.id==int(id)).first()
        if res is None: return error("Post not found"), 404

        # 如果文章已經公開
        if res.mark == "visible":
            return error("Post is already visible."), 400
        elif res.mark == "pending":
            res.mark = "visible"
            session.commit()

            # run IG Post

            return jsonify({"result":"OK"}), 200
        else:
            return error("Post mark error"), 500

####################
#   Setting Area   #
####################
# get / set
@admin.route("/setting", methods=["GET"])
@role_required(["setting.edit"])
def setting_get():
    return jsonify(setting_loader.loadset()), 200

@admin.route("/setting", methods=["POST"])
@role_required(["setting.edit"])
def setting_edit():
    opuser = g.opuser.user

    req = request.json
    d = None
    for r in req:
        d = setting_loader.writeset(r, req.get(r))
        if d == 0: return error("Failed"), 401
    logger.logger("setting.modify", "User:%s modified settings: %s"%(opuser, json.dumps(request.json)))

    return jsonify(d), 200