#!/usr/bin/env python
############################################################################
#
# MODULE:       d.vect.colboxplot
# AUTHOR:       Paulo van Breugel
# PURPOSE:      Draws the boxplot(s) of values in a vector attribute column
#
# COPYRIGHT:    (c) 2019 Paulo van Breugel, and the GRASS Development Team
#               This program is free software under the GNU General Public
#               License (>=v2). Read the file COPYING that comes with GRASS
#               for details.
#
#############################################################################

#%module
#% description: Draws the boxplot of values in a vector attribute column
#% keyword: display
#% keyword: vector
#% keyword: plot
#% keyword: histogram
#% keyword: boxplot
#%end

#%option G_OPT_V_MAP
#% guisection: General
#%end

#%option G_OPT_V_FIELD
#%end

#%option G_OPT_DB_COLUMN
#% key: column
#% description: Attribute column value to be plotted
#% required: yes
#% guisection: General
#%end

#%option G_OPT_DB_WHERE
#%guisection: General
#%end

#%option G_OPT_F_OUTPUT
#% key: plot_output
#% required: no
#% guisection: General
#%end

#%option G_OPT_DB_COLUMN
#% key: group_by
#% description: Attribute column with categories to group the data by
#% required: no
#% guisection: Plot options
#%end

#%option
#% key: order
#% type: string
#% label: Sort boxplots
#% description: Sort boxplots based on their median values
#% required: no
#% options: descending,ascending
#% guisection: Plot options
#%end

#%flag
#% key: h
#% label: horizontal boxplot(s)
#% description: Draw the boxplot horizontal
#% guisection: Plot options
#%end

#%flag
#% key: o
#% label: hide outliers
#% description: Draw boxplot(s) without outliers
#% guisection: Plot options
#%end

#%flag
#% key: n
#% label: notch
#% description: Draw boxplot(s) with notch
#% guisection: Plot options
#%end

#%flag
#% key: r
#% label: Rotate labels
#% description: rotate x-axis labels
#% guisection: Plot options
#%end

import sys
import matplotlib #required by windows
matplotlib.use('wxAGG') #required by windows
import matplotlib.pyplot as plt
import grass.script as gscript
import operator
import numpy as np

def main():
    # input
    vector = options['map']
    column = options['column']
    group_by = options['group_by'] if options['group_by'] else None
    output = options['plot_output'] if options['plot_output'] else None
    where = options['where'] + " AND " + column + " IS NOT NULL" \
            if options['where'] else column + " IS NOT NULL"
    sort = options['order'] if options['order'] else None
    if sort == 'descending':
        reverse = True
    elif sort == 'ascending':
        reverse = False
    else:
        reverse = None
    cols = filter(None, [group_by, column])
    flag_h = not flags['h']
    flag_o = not flags['o']
    flag_n = flags['n']
    flag_r = flags['r']
    
    # Get data with where clause
    if where:
        df=[x for x in gscript.read_command('v.db.select',
                                            map_=vector,
                                            column=cols,
                                            where=where,
                                            flags='c').splitlines()]
    # Get all column data
    else:
        df=[x for x in gscript.read_command('v.db.select',
                                            map_=vector,
                                            column=cols,
                                            flags='c').splitlines()]
    # for grouped boxplot
    if group_by:
        # Split columns and create list with data and with labels
        df=[x.split('|') for x in df]
        vals = [float(i[1]) for i in df]
        groups = [i[0] for i in df] 
        uid = list(set(groups))
        data = []
        sf = []
        for i,m in enumerate(uid):
            a = [ j for j, grp in enumerate(groups) if grp == m]
            data.append([vals[i] for i in a])
            sf.append([m, np.median([vals[i] for i in a])])
        
        # Order boxes
        if sort:
            sf.sort(key = operator.itemgetter(1), reverse=reverse)
        sf = [i[0] for i in sf] 
        ii = { e: i for i, e in enumerate(sf) }
        sfo = [(ii[e]) for i, e in enumerate(uid) if e in ii]
      
        # Draw boxplot
        plt.boxplot(data, notch=flag_n, sym='gD', labels=uid, vert=flag_h,
                        showfliers=flag_o, positions=sfo)
    else:
        data=[float(x) for x in df]
        plt.boxplot(data, notch=flag_n, sym='gD', vert=flag_h,
                        showfliers=flag_o)
    if flag_r:
        plt.xticks(rotation=90)
    plt.tight_layout()
    if output:
        plt.savefig(output)
    else:
        plt.show()
        
if __name__ == "__main__":
    options, flags = gscript.parser()
    main()