/climate.py

'''
The MIT License (MIT)
Copyright (c) 2016 Suhas SG

API
---

## Climate summaries

    /state?id=
    /district?id=
    /subdistrict?id=
    /village?id=


    {
        "state_code": "...",
        "metric_a": "...",
        "metric_b": "...",
        ...
    }

## Time series for a metric

    /state?id=&metric=
    /district?id=&metric=
    /subdistrict?id=&metric=
    /village?id=&metric=

    {
        "state_code": "...",
        "metric": {
            "1984": "...",
            ...
        }
    }

'''
import os
import yaml
import logging
import StringIO
import sqlalchemy
import pandas as pd
import json
from flask import Flask
from flask import request
from flask import make_response
from flask import send_from_directory
from flask import render_template, jsonify
from orderedattrdict.yamlutils import AttrDictYAMLLoader
app = Flask(__name__)

logging.basicConfig(
    format='%(asctime)s|%(levelname)s|%(message)s',
    level=logging.INFO
)


cfg = yaml.load(open('config.yaml'), Loader=AttrDictYAMLLoader)


def connect():
    '''Returns a connection and a metadata object'''
    con = sqlalchemy.create_engine(cfg.dburl, client_encoding='utf8')
    meta = sqlalchemy.MetaData(bind=con, reflect=True)
    return con, meta

con, meta = connect()
lookup = pd.read_csv('lookup_villages.csv')


@app.route('/')
def explore():
    return render_template('index.html')


@app.route('/<level>')
def metrics(level):
    '''
    Get metrics for the following levels:
        - /state?id=
        - /district?id=
        - /subdistrict?id=
        - /village?id=
    '''
    table, col = cfg.api[level].table, cfg.api[level].col

    # Filter
    table = meta.tables[table]
    claus = table.select().where(table.c[col] == request.args.get('id'))

    # Select
    df = pd.read_sql(claus, con)

    if len(df) == 0:
        return jsonify(**{})

    if 'metric' in request.args:
        res = {
            col: df[col].iloc[0],
            'data': df[[request.args.get('metric'), 'year']].to_dict(orient='records')
        }
        return jsonify(**res)

    # Clean
    del df['year']
    return jsonify(**df.mean().to_dict())


def get_data(table, col, val):
    table = meta.tables[table]
    claus = table.select().where(table.c[col] == val)
    df = pd.read_sql(claus, con)
    return df


@app.route('/lookup')
def lookitup():
    '''
    Lookup one level with another
        - /lookup?id=&lookup=state&for=district
        - /lookup?id=&lookup=district&for=subdistrict
        - /lookup?id=&lookup=subdistrict&for=village

    # Example: Get all villages of a particular subdistrict
        - /lookup?for=subdistrict&id=345&lookup=village
    '''
    lev = request.args.get('for')
    par = request.args.get('lookup')
    col, val = '%s_code' % lev, request.args.get('id')

    if par == 'village':
        dat = lookup[lookup[col] == int(val)][['%s_code' % par, '%s_name' % par]]
        res = {}
        if len(dat):
            return jsonify(**{
                "village": dat.to_dict(orient='records'),
                lev: int(val)
            })

    dat = lookup[lookup[col] == int(val)]['%s_code' % par]
    res = {}
    if len(dat):
        dat = map(int, dat.unique())
        res = {par: list(dat) if len(dat) > 1 else dat[0], lev: int(val)}

    return jsonify(**res)


@app.route('/favicon.ico')
def favicon():
    return send_from_directory(
        os.path.join(app.root_path, 'static'),
        'favicon.ico', mimetype='image/vnd.microsoft.icon'
    )


@app.route('/subdistmap')
def getdistmap():
    with open('static/subdist.json') as distmap:
        distmap = json.load(distmap)

    temp = distmap['objects']['subdist_2011_splitcode']['geometries']
    newgeos = []
    for geo in temp:
        t = geo['properties']['dist_code']
        if t == int(request.args.get('code')):
            newgeos.append(geo)

    distmap['objects']['subdist_2011_splitcode']['geometries'] = newgeos
    return jsonify(**distmap)


@app.route('/download/<level>')
def download(level):
    table, col = cfg.api[level].table, cfg.api[level].col
    val = request.args.get('id')

    _df = get_data(table, col, val)
    si = StringIO.StringIO()
    _df.to_csv(si, index=False)
    output = make_response(si.getvalue())
    output.headers["Content-Disposition"] = "attachment; filename=data-{}.csv".format(val)
    output.headers["Content-type"] = "text/csv"
    return output


if __name__ == '__main__':
    app.run(host='0.0.0.0', port=9500, debug=True)