"""
@author: James Larsson
@collaborators: None
"""

import arcpy  # Import the ArcPy module
import time
import datetime

arcpy.env.workspace = arcpy.GetParameterAsText(0)  # Get 'Workspace' parameter from ArcGIS
arcpy.env.overwriteOutput = True  # Allow output to overwrite

input_pts = arcpy.GetParameterAsText(1)  # Snapped points
flowdir = arcpy.GetParameterAsText(2) # D8 Flow direction raster
output_fc = arcpy.GetParameterAsText(3) # Output vector

print("Creating cursor")
fields = ["OBJECTID"]  # Select subset of fields from species observations shapefile to include
cursor = arcpy.da.SearchCursor(input_pts, "*")  # Create search cursor for observations shapefile
count = 0  # Set count to 0
total_rows = arcpy.management.GetCount(input_pts)[0]
global_start_time = time.time()
print("Beginning create watersheds")
for row in cursor:  # For each row in feature class
    start_time = time.time()
    if(count > 0):
        print("Estimated time remaining: %s " % datetime.timedelta(seconds = (((start_time-global_start_time)/count)*(int(total_rows)-count))))  # timedelta from https://www.geeksforgeeks.org/python-program-to-convert-seconds-into-hours-minutes-and-seconds/

    print("Running on row %s" % count)

    where_clause = " \"OBJECTID\" = %s " % row[0]  # Where clause to select schools with zero hospitals in 3-mile buffer
    arcpy.management.MakeFeatureLayer(input_pts, "lyr")  # Feature layer from Schools.shp
    arcpy.management.SelectLayerByAttribute("lyr", "NEW_SELECTION", where_clause)
    arcpy.management.CopyFeatures("lyr", "current_pt")

    print("Creating watershed raster...")
    watershed = arcpy.sa.Watershed(flowdir, "current_pt")

    print("Converting to polygon...")
    arcpy.conversion.RasterToPolygon(watershed, "current_watershed")
    arcpy.management.Dissolve("current_watershed", "dissolved")
    arcpy.management.JoinField("dissolved", "OBJECTID", "current_pt","OBJECTID")

    print("Attaching to output")
    if count == 0:  # If this is the first observation processed, create a new feature class at location output_fc
        arcpy.management.CopyFeatures("dissolved", output_fc)  # Copy new shape to output feature class
        arcpy.AddMessage("  Created new feature class for %s with basin ID %s" % (output_fc, row[0]))
    else:
        arcpy.management.Append("dissolved", output_fc)  # Append new shape to output feature class
        arcpy.AddMessage("  Appended to feature class %s with basin ID %s" % (output_fc, row[0]))

    print("Cleaning up")
    arcpy.management.Delete(watershed)

    print("Time elapsed for point: %.2f sec" % (time.time()-start_time))

    count += 1  # Increment count