# python 3.5
#requires LAStools to be installed (with the appropriate license). Note that LAStools requires no spaces in file names

#should have previously run 2017088_las_manipulation to have a las that has the buildings and veg removed
#note that the neilson volumes script must be in the same folder

# this script will:
#crop to a given polygon (crop away the swash zone)
# extract values along a predefined profile,
# do the volume analysis
#export pngs of the surveys
########################### IMPORTS ###########################################
import os
import io
import re
import sys
import math
import argparse
import datetime
import subprocess
import numpy as np
import pandas as pd
from cycler import cycler
import matplotlib.pyplot as plt
from matplotlib.ticker import MultipleLocator

import nielsen_volumes
from survey_tools import call_lastools, extract_pts, update_survey_output


def get_datestring(x):
    """Format a date integer into an ISO-8601 date string

    Args:
        x:  unformatted date

    Returns:
        formatted date string

    Examples:

    >> get_datestring(19700101)
    '1970-01-01'
    """
    datestr = pd.datetime.strptime(str(x), '%Y%m%d').strftime('%Y-%m-%d')

    return datestr


def remove_temp_files(directory):
    for f in os.listdir(directory):
        os.unlink(os.path.join(directory, f))

    return None


def plot_profiles(profile_name, csv_output_dir, graph_loc, ch_limits, delta_vol, survey_date):
    csv_name = profile_name + '.csv'
    profiles = pd.read_csv(os.path.join(csv_output_dir, csv_name))

    # Remove metadata, and extract profile coordinates
    profiles = profiles.loc[:, 'Chainage':].set_index('Chainage')

    # Determine if current survey is the latest
    current_survey_col = 'Elevation_' + survey_date
    is_latest = profiles.columns[-1] == current_survey_col

    # Only plot profiles up to current survey date
    profiles = profiles.loc[:, :current_survey_col]

    # Find landward limit of profile (behind beach)
    ch_min = ch_limits.loc[profile_name, 'Landward Limit']

    # Set figure dimensions based on beach size
    vertical_exag = 8
    m_per_inch = 8
    fig_h = profiles.dropna().values.max() / m_per_inch * vertical_exag
    fig_w = (profiles.index.max() - ch_min) / m_per_inch

    fig, ax = plt.subplots(figsize=(fig_w, fig_h))
    for col in profiles.columns:
        profile = profiles.loc[ch_min:, col]
        date_str = col.split('_')[-1]
        date = get_datestring(date_str)

        ax.plot(profile.index, profile, label=date)

    ax.set_aspect(vertical_exag)

    ax.set_xlabel('Chainage (m)', labelpad=10)
    ax.set_ylabel('Elevation (m AHD)', labelpad=10)

    # Show most recent volume change
    if delta_vol is not None:
        ax.annotate('Most recent\nvolume change:\n{:0.1f} m$^3$/m'.format(delta_vol),
                    (0.05, 0.15), xycoords='axes fraction', fontsize=9,
                    backgroundcolor='#ffffff', linespacing=1.5)

    ax.legend(edgecolor='none', facecolor='#ffffff', fontsize=9)

    ax.xaxis.set_minor_locator(MultipleLocator(5))
    ax.yaxis.set_minor_locator(MultipleLocator(0.5))
    ax.xaxis.grid(True, which='minor', color='k', linewidth=0.5, alpha=0.3)
    ax.yaxis.grid(True,which='minor',color='k', linewidth=0.5, alpha=0.3)

    # Save in folder with current date
    png_dirs = [os.path.join(graph_loc, get_datestring(survey_date))]
    if is_latest:
        # Save copy in'latest' if survey is most recent
        png_dirs += [os.path.join(graph_loc, 'latest')]

    for png_dir in png_dirs:
        # Prepare output directory
        try:
            os.makedirs(png_dir)
        except FileExistsError:
            pass

        png_name = os.path.join(png_dir, profile_name + '.png')
        plt.savefig(png_name, bbox_inches='tight', dpi=300)
    plt.close()


def calculate_volumes(profile_name, survey_date, csv_output_dir, ch_limits, volume_output_dir):
    csv_prof = profile_name + '.csv'
    beach = re.search('.*(?=_\d)', profile_name).group()
    profiles = pd.read_csv(os.path.join(csv_output_dir, csv_prof))

    # Remove metadata, and extract profile coordinates
    profiles = profiles.loc[:, 'Chainage':].set_index('Chainage')

    # Find landward limit of profile (behind beach)
    ch_min = ch_limits.loc[profile_name, 'Landward Limit']

    # Open volume spreadsheet
    csv_vol = os.path.join(volume_output_dir, 'volumes.csv')
    try:
        volumes = pd.read_csv(csv_vol, index_col=0)
    except FileNotFoundError:
        # Create new dataframe if csv does not exist
        volumes = pd.DataFrame()

    for current_date in profiles.columns:
        # Get Nielsen erosion volumes
        chainage = profiles.loc[:, current_date].dropna().index
        elevation = profiles.loc[:, current_date].dropna().values
        volume = nielsen_volumes.volume_available(chainage, elevation, ch_min)

        # Update spreadsheet
        volumes.loc[profile_name, 'Volume_' + survey_date] = volume

    # Save updated volumes spreadsheet
    volumes = volumes[volumes.columns.sort_values()]
    volumes = volumes.sort_index()
    volumes.to_csv(csv_vol)

    # Get most recent volume difference for current profile
    try:
        previous_vol = volumes.loc[profile_name].values[-2]
        current_vol = volumes.loc[profile_name].values[-1]
        delta_vol = current_vol - previous_vol
    except IndexError:
        # Return None if there is only one survey
        delta_vol = None

    return delta_vol


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'input_file',
        metavar='PARAMS_FILE',
        help='name of parameter file',
        default=None)

    # Print usage if no arguments are provided
    if len(sys.argv) == 1:
        parser.print_help(sys.stderr)
        sys.exit(1)

    args = parser.parse_args()

    # read the parameters file and scroll through it
    input_file = args.input_file
    params_file=pd.read_excel(input_file, sheet_name="PARAMS")

    for i, row in params_file.iterrows():
        print("Starting to process %s" % row['BEACH'])
        beach=row['BEACH']
        survey_date = str(row['SURVEY DATE'])
        original_las = row['INPUT LAS']
        classified_las_dir = row['LAS CLASSIFIED FOLDER']
        shp_swash_dir = row['SHP SWASH FOLDER']
        crop_heatmap_poly = row['HEATMAP CROP POLY']
        output_las_dir = row['LAS OUTPUT FOLDER']
        zone_MGA = row['ZONE MGA']
        output_poly_dir = row['SHP RASTER FOLDER']
        output_tif_dir = row['TIF OUTPUT FOLDER']
        cp_csv = row['INPUT CSV']
        profile_limit_file = row['PROFILE LIMIT FILE']
        csv_output_dir = row['CSV OUTPUT FOLDER']
        graph_loc = row['PNG OUTPUT FOLDER']
        volume_output_dir = row['CSV VOLUMES FOLDER']
        tmp_dir = row['TMP FOLDER']

        # Get base name of input las
        las_basename = os.path.splitext(os.path.basename(original_las))[0]

        # Get name of input point cloud
        input_las = os.path.join(classified_las_dir, las_basename + '.las')

        # Get name of swash cropping polygon
        crop_swash_poly = os.path.join(shp_swash_dir, las_basename + '.shp')

        # Crop point cloud to swash boundary
        print('Cropping swash...')
        las_data = call_lastools('lasclip', input=input_las, output='-stdout',
                                 args=['-poly', crop_swash_poly], verbose=False)

        # Apply sea-side clipping polygon
        print('Cropping back of beach...')
        las_data = call_lastools('lasclip', input=las_data, output='-stdout',
                                 args=['-poly', crop_heatmap_poly], verbose=False)

        # Create clipping polygon for heatmap raster
        print('Creating heat map cropping polygon...')
        shp_name = os.path.join(output_poly_dir, las_basename + '.shp')
        call_lastools('lasboundary', input=las_data, output=shp_name, verbose=False)

        # Make a raster from point cloud
        print('Creating heat map raster...')
        tif_name = os.path.join(output_tif_dir, las_basename + '.tif')
        call_lastools('las2dem', input=las_data, output=tif_name,
                      args=['-step', 0.2, '-keep_class', 2], verbose=False)

        # Extract elevations along profiles from triangulated surface
        print('Extracting profile elevations...')
        df = extract_pts(
            las_data,
            cp_csv,
            survey_date,
            beach,
            args=['-parse', 'sxyz', '-keep_class', '2'],
            verbose=False)

        # Update survey profiles
        update_survey_output(df, csv_output_dir)

        # Get landward limit of surveys
        ch_limits = pd.read_excel(profile_limit_file, index_col='Profile')

        # Plot profiles, and save sand volumes for current beach
        print('Updating figures...')
        profile_names = df['Profile'].unique()
        for profile_name in profile_names:
            delta_vol = calculate_volumes(profile_name, survey_date,
                                          csv_output_dir, ch_limits,
                                          volume_output_dir)
            plot_profiles(profile_name, csv_output_dir, graph_loc, ch_limits,
                          delta_vol, survey_date)

        # Remove temprary files
        remove_temp_files(tmp_dir)


if __name__ == '__main__':
    main()