from flask import Blueprint, request, current_app, abort, jsonify, make_response, abort
import jwt, os, time, math
from utils import pgclass, setting_loader, logger
from utils.platform_consts import pList, pList_root
from functools import wraps
from sqlalchemy.orm import sessionmaker
from sqlalchemy import desc
from bcrypt import hashpw, gensalt, checkpw

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
            key = os.getenv("JWT_KEY", None)
            jwtsession = request.cookies.get("token", None)
            if jwtsession == None: return "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 "Token expired!", 401
            except jwt.exceptions.DecodeError: return "Invalid token!", 401
            if "id" not in jwtdata or "user" not in jwtdata: return "Invalid token!", 401
            
            # db
            db = current_app.shared_resource.engine
            Session = sessionmaker(bind=db)
            session = Session()
            table = pgclass.SQLuser
            res = session.query(table).filter(table.user == jwtdata["user"], table.id == jwtdata["id"]).first()
            session.close()
            if res is None: return "You do not have permission to view this page.", 401

            # permission check
            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 "The user has invalid permission.", 402
            for p in list(set(permreq)):
                if p not in permissionList: return "You do not have permission to view this page.", 402

            # return
            return f(*args, **kwargs)
        return decorated_function
    return decorator
# get operator
def getopuser(session, cookie):
    table = pgclass.SQLuser
    jwtsession = str(cookie)
    try: opuser = jwt.decode(jwt = jwtsession, key = os.getenv("JWT_KEY"), algorithms = ["HS256"])
    except jwt.exceptions.ExpiredSignatureError: return "Token expired!", 401
    except jwt.exceptions.DecodeError: return "Invalid token!", 401
    if "id" not in opuser or "user" not in opuser: return "Invalid token!", 401
    opuser = session.query(table).filter(table.user==opuser["user"],table.id==opuser["id"]).first()
    return opuser, None

# login
@admin.route("/login", methods=["POST"])
def login():
    # args
    if "username" not in request.json or "password" not in request.json: return "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
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    table = pgclass.SQLuser
    with Session() as session: u = session.query(table).filter(table.user==username).first()
    # auth
    if u is None: return "Login Failed", 401 # 找不到用戶
    if not checkpw(password.encode("utf-8"), u.password.encode("utf-8")): return "Login Failed", 401 # 密碼沒法跟hash對上
    
    # jwt
    key = os.getenv("JWT_KEY", None)
    if key is None: return abort(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(db, "login", "User:%s logined"%username)

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

@admin.route("me", methods=["GET"])
@role_required([])
def user_me():
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    with Session() as session:
        opuser, err = getopuser(session, request.cookies.get("token"))
        if err is not None: return opuser, err
    return jsonify({"id":opuser.id, "user":opuser.user, "permission":opuser.permission})

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

@admin.route("user/get/<int:id>", methods=["GET"])
@role_required([])
def user_get(id:int):
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    table = pgclass.SQLuser
    with Session() as session: users = session.query(table).filter(table.id==int(id)).all()
    res = [ {"id":u.id, "user":u.user, "permission":u.permission} for u in users ]

    return jsonify(res)

@admin.route("user/add", methods=["POST"])
@role_required(["usermgr"])
def user_add():
    # db 
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    table = pgclass.SQLuser
    with Session() as session:
        # user who requested
        opuser, err = getopuser(session, request.cookies.get("token"))
        if err is not None: return opuser, err
        if opuser is None: return "You don't have permission to view this page!", 402
        
        # 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 "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 "Invalid Username or Password!", 400
        # check permission list
        for p in permission:
            if p not in pList: return "Invalid Permission", 400 # 如果添加的權限名稱不合法
            if p not in opuser.permission: return "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(db, "user.create", "User:%s created a new user:%s"%(opuser.user, username)) # logger
            return jsonify({"user":username, "permission":permission})
        else:
            return "User already exist!"

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

    with Session() as session:
        # user who requested
        opuser, err = getopuser(session, request.cookies.get("token"))
        if err is not None: return opuser, err
        if opuser is None: return "You don't have permission to view this page!", 402
    
        # check root
        tguser = session.query(table).filter(table.id==int(id)).first()
        if tguser is None: return "User is not exist", 400
        if tguser.user == "root": return "You cannot delete user:root", 400
    
        # delete
        session.delete(tguser)
        session.commit()

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

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

@admin.route('article/list', methods = ["GET"])
@role_required(["article.read"])
def article_list():
    # variables
    if request.args.get("start") is None or request.args.get("count") is None or \
        request.args.get("start").isdigit()==False or request.args.get("count").isdigit()==False: return "Arguments error", 400
    rst = int(request.args.get("start"))
    count = int(request.args.get("count"))

    # db
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    # get ctx
    table = pgclass.SQLarticle
    ftab = pgclass.SQLfile
    with Session() as session: res = session.query(table).order_by(desc(table.id)).filter(table.reference == None).offset(rst).limit(count).all()

    # mapping
    res = [ {"id":r.id, "ctx":r.ctx, "igid":r.igid, "created_at":r.created_at, "mark":r.mark, "ip":r.ip,
             "files": [ f[0] for f in session.query(ftab.id).filter(ftab.reference == r.hash).all() ] } for r in res ]

    return jsonify(res), 200

@admin.route("article/get/<int:id>", methods=["GET"])
@role_required(["article.read"])
def article_read(id:int):
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    table = pgclass.SQLarticle
    ftab  = pgclass.SQLfile
    # get ctx
    with Session() as session: res = session.query(table).filter(table.id == int(id)).first()
    # mapping
    resfn = {
        "id":res.id, "ctx":res.ctx, "igid":res.igid, "created_at":res.created_at, "mark":res.mark, "reference":res.reference, "ip":res.ip,
        "files": [ f[0] for f in session.query(ftab.id).filter(ftab.reference==res.hash).all() ],
        "comment": [ c[0] for c in session.query(table.id).filter(table.reference==res.id).all() ]
    }
    return jsonify([resfn])

@admin.route("article/delete/<int:id>", methods=["DELETE"])
@role_required(["article.del"])
def article_del(id:int):
    # db
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    table = pgclass.SQLarticle
    ftab = pgclass.SQLfile

    with Session() as session:
        opuser, err = getopuser(session, request.cookies.get("token"))
        if err is not None: return opuser, err

        res = session.query(table).filter(table.id == id).first()     # 本體
        session.query(ftab).filter(ftab.reference == res.hash).delete() # 檔案

        rcl = []
        # 留言
        for c in session.query(table).filter(table.reference == res.id).all():
            rcl.append(c.id)
            # 刪留言的檔案
            session.query(ftab).filter(ftab.reference == c.hash).delete()
            # 刪留言
            session.delete(c)
        # 刪本體
        session.delete(res)
        # commit
        session.commit()
        # logger
        logger.logger(db, "article.delete", "User:%s deleted post (id=%d with comments %s): last_status=%s"%(opuser.user, res.id, str(rcl), res.mark))
        return "OK", 200

@admin.route("article/pend/<int:id>", methods=["PATCH"])
@role_required(["article.pend"])
def article_pend(id:int):
    # db
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)
    table = pgclass.SQLarticle
    with Session() as session:
        # 確保文章存在
        res = session.query(table).filter(table.id==int(id)).first()
        if res is None: return "Post not found", 400

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

            # run IG Post

            return "OK", 200
        else:
            return "Post mark error", 500

@admin.route("article/file/<int:id>", methods = ["GET"])
@role_required(["article.read"])
def article_fileget(id:int):
    db = current_app.shared_resource.engine
    Session = sessionmaker(bind=db)

    table = pgclass.SQLarticle
    ftab  = pgclass.SQLfile
    with Session() as session:
        fres = session.query(ftab).filter(ftab.id == id).first()
        if fres is None: return "File not found", 400       # 檢查檔案是否存在
        article = session.query(table).filter(table.hash == fres.reference).first()
        if article is None: return "File not found", 400    # 檢查文章本體是否存在
    resp = make_response(fres.binary)
    resp.headers.set("Content-Type", fres.type)
    resp.headers.set("Content-Disposition", f"attachment; filename=file{fres.id}")
    return resp

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

@admin.route("setting/set", methods=["POST"])
@role_required(["setting.edit"])
def setting_edit():
    req = request.json
    d = None
    for r in req:
        d = setting_loader.writeset(r, req.get(r))
        if d == 0: return "Failed", 401
    return jsonify(d), 200