#!/usr/bin/env python3

from os import environ
from flask import Flask, request, render_template

from .pg import query, select

app = Flask(__name__)

@app.route('/')
def home():
    if 'filter' in request.args:
        messages = select(
            '''
                SELECT * FROM messages
                ORDER BY date DESC
                WHERE from_url = :filter
                OR to_url = :filter
            ''',
            filter=request.args['filter']
        )
    else:
        messages = select(
            '''
                SELECT * FROM messages
                ORDER BY date DESC
                LIMIT 100
            '''
        )

    return render_template(
        "home.html",
        users=select(
            '''
                SELECT DISTINCT ON (url) url, name
                FROM (
                  (
                    SELECT DISTINCT ON (from_url) from_url as url, from_name as name
                    FROM messages
                    ORDER BY url, date DESC
                  )
                  UNION
                  (
                    SELECT DISTINCT ON (to_url) to_url as url, to_name as name
                    FROM messages
                    ORDER BY url, date DESC
                  )
                ) as nested;
            '''
        ),
        messages=messages,
    )