import json
import os
import psycopg2
from psycopg2 import pool
from psycopg2.extras import RealDictCursor
from urllib.parse import urlparse
from flask import g

class DataBase():
    def __init__(self):
        self.pool = None

    def init_app(self, app):
        db_url = urlparse(os.environ['DATABASE_URL'])
        if not db_url:
            raise Exception("No DATABASE_URL environment variable set")
        
        self.pool = psycopg2.pool.SimpleConnectionPool(
            1, 20,
            database=db_url.path[1:],
            user=db_url.username,
            password=db_url.password,
            host=db_url.hostname,
            port=db_url.port
        )
        
        app.teardown_appcontext(self.close_conn)

    def get_conn(self):
        if 'db_conn' not in g:
            g.db_conn = self.pool.getconn()
        return g.db_conn

    def close_conn(self, e=None):
        db_conn = g.pop('db_conn', None)
        if db_conn is not None:
            self.pool.putconn(db_conn)

    def close_all_connections(self):
        if self.pool:
            self.pool.closeall()

    def execute(self, query, args=(), one=False, commit=False):
        conn = self.get_conn()
        cur = conn.cursor(cursor_factory=RealDictCursor)
        try:
            cur.execute(query, args)
            rv = None
            if cur.description is not None:
                rv = cur.fetchall()
            if commit:
                conn.commit()
            return (rv[0] if rv else None) if one else rv
        except Exception as e:
            conn.rollback()
            raise e
        finally:
            cur.close()
    
    def get_http_functions_for_user(self, user_id):
        http_functions = self.execute(
            'SELECT id, user_id, NAME, script_content, invoked_count, environment_info, is_public, log_request, log_response, version_number, runtime FROM http_functions WHERE user_id=%s ORDER by id DESC', [user_id])
        return http_functions
    
    def get_http_function(self, user_id, name):
        http_function = self.execute(
            'SELECT id, user_id, NAME, script_content, invoked_count, environment_info, is_public, log_request, log_response, version_number, created_at, runtime FROM http_functions WHERE user_id=%s AND NAME=%s', [user_id, name], one=True)
        return http_function
    
    def get_http_function_by_id(self, user_id, http_function_id):
        http_function = self.execute(
            'SELECT id, user_id, NAME, script_content, invoked_count, environment_info, is_public, log_request, log_response, version_number, created_at, runtime FROM http_functions WHERE user_id=%s AND id=%s', [user_id, http_function_id], one=True)
        return http_function
    
    def create_new_http_function(self, user_id, name, script_content, environment_info, is_public, log_request, log_response, runtime):
        self.execute(
            'INSERT INTO http_functions (user_id, NAME, script_content, environment_info, is_public, log_request, log_response, runtime) VALUES (%s, %s, %s, %s, %s, %s, %s, %s)',
            [user_id, name, script_content, environment_info, is_public, log_request, log_response, runtime],
            commit=True
        )

    def edit_http_function(self, user_id, function_id, name, script_content, environment_info, is_public, log_request, log_response, runtime):
        updated_version = self.execute(
            'UPDATE http_functions SET NAME=%s, script_content=%s, environment_info=%s, is_public=%s, log_request=%s, log_response=%s, runtime=%s WHERE user_id=%s AND id=%s RETURNING version_number',
            [name, script_content, environment_info, is_public, log_request, log_response, runtime, user_id, function_id],
            commit=True, one=True
        )
        return updated_version
    
    def update_http_function_environment_info_and_invoked_count(self, user_id, name, environment_info):
        self.execute(
            'UPDATE http_functions SET environment_info=%s, invoked_count = invoked_count + 1 WHERE user_id=%s AND NAME=%s', [json.dumps(environment_info), user_id, name], commit=True)

    def delete_http_function(self, user_id, function_id):
        self.execute(
            'DELETE FROM http_functions WHERE user_id=%s AND id=%s', [user_id, function_id], commit=True)

    def add_http_function_invocation(self, http_function_id, status, request_data, response_data, logs, version_number, execution_time):
        self.execute(
            'INSERT INTO http_function_invocations (http_function_id, status, request_data, response_data, logs, version_number, execution_time) VALUES (%s, %s, %s, %s, %s, %s, %s)', [http_function_id, status, json.dumps(request_data), json.dumps(response_data), json.dumps(logs), version_number, execution_time], commit=True)

    def get_http_function_invocations(self, http_function_id):
        http_function_invocations = self.execute(
            """SELECT id, http_function_id, STATUS, invocation_time, request_data, response_data, LOGS, version_number, execution_time
FROM http_function_invocations
WHERE http_function_id=%s
ORDER BY invocation_time DESC""", [http_function_id])
        return http_function_invocations
    
    def get_user(self, user_id):
        user = self.execute(
            'SELECT id, username, password_hash, created_at FROM users WHERE id=%s', [int(user_id)], one=True)
        return user

    def get_user_by_username(self, username):
        user = self.execute(
            'SELECT id, username, password_hash, created_at FROM users WHERE username=%s', [username], one=True)
        return user

    def create_new_user(self, username, password_hash):
        new_user = self.execute(
            'INSERT INTO users (username, password_hash) VALUES (%s, %s) RETURNING id, username, password_hash, created_at', [username, password_hash], commit=True, one=True)
        return new_user
    
    def get_http_function_history(self, function_id):
        http_function_history = self.execute(
            'SELECT version_id, http_function_id, script_content, version_number, updated_at FROM http_functions_versions WHERE http_function_id=%s ORDER BY version_number DESC', [function_id])
        return http_function_history