#--------------------------------------------------------------------------
# Tool Name:  SmartConservation GreenPlan AddFields
# Source Name: AddingFields.py
# Version: ArcGIS 9.0
# Author: Robert Cheetham cheetham@avencia.com
#
# This script will add or overwrite a field to the input
# feature class and populate that field with feature areas. 
#--------------------------------------------------------------------------

#--------------------------------------------------------------------------
#Imports
#--------------------------------------------------------------------------
from win32com.client import constants, Dispatch
from types import *
import pythoncom, sys, os, math, string

# HelperFunctions.py contains functions and custom classed used by all
# the Stat tools and utilities.
# from SCMHelperFunctions import *

#--------------------------------------------------------------------------
#MAIN

sAreaMetersField = "AREA_MTR"
sAreaAcresField = "AREA_ACRE"
sAreaRankField = "AREA_RANK"
sRoundednessField = "SHP_RANK"
sResultsField = "SC_SCORE"

SQ_METERS_IN_ACRES = 4047
CONS_VALUE_WEIGHT = 0.70
AREA_WEIGHT = 0.20
ROUNDEDNESS_WEIGHT = 0.10

# print "Area Field: ", sAreaMetersField
# print "Perimeter Field: ", sRoundednessField
# print "Results/Score Field: ", sResultsField

try: pGP = Dispatch("esriGeoprocessing.GPDispatch.1")
except: raise "Error creating the geoprocessing dispatch object."
pGP.SetProduct("ArcView") 

#Get input feature class   
try:
    sInputFC = sys.argv[1]  # Input Feature Class
    sOutputFC = sys.argv[2]  # Output Feature Class
    sValueField = sys.argv[3]  # The value field
except: raise "Invalid Arguments"
#Copy the input feature class into the output feature class.

# print "sInputFC: ", sInputFC
# print "sOutputFC: ", sOutputFC
# print "sValueField: ", sValueField

try:
    pGP.copyfeatures(sInputFC, sOutputFC)
except:
    sMessage = "Cannot overwrite output feature class: %s" % (sOutputFC)
    sErrors = pGP.GetMessages(2)
    sOutMessage = sMessage + "... " + sErrors
    raise sOutMessage

#Get feature class information: fields, shapefile, etc.
pFCInfo = pGP.Describe(sInputFC)
pFields = pGP.ListFields(sInputFC)
if string.lower(pFCInfo.ShapeType) <> "polygon": raise "Only Polygons are valid input feature classes"

# Add AREA_MTR field.
try:
    pGP.AddField(sOutputFC, sAreaMetersField, "DOUBLE")
except:
    pGP.AddWarning("Area field exists")
# Add AREA_ACRE field.
try:
    pGP.AddField(sOutputFC, sAreaAcresField, "DOUBLE")
except:
    pGP.AddWarning("Area Acres field exists")
# Add AREA_RANK field.
try:
    pGP.AddField(sOutputFC, sAreaRankField, "DOUBLE")
except:
    pGP.AddWarning("Area Rank field exists")
# Add ROUNDEDNESS (SHP_RANK) field.
try:
    pGP.AddField(sOutputFC, sRoundednessField, "DOUBLE")
except:
    pGP.AddWarning("Perimeter field exists")

# Add results SCORE field.
try:
    pGP.AddField(sOutputFC, sResultsField, "DOUBLE")
except:
    pGP.AddWarning("Score field exists")

pRows = pGP.UpdateCursor(sOutputFC)
pRow = pRows.Next()
while pRow <> None:
    pGeometry = pRow.GetValue (pFCInfo.ShapeFieldName)
    dArea = pGeometry.Area
    # Set Acres by dividing Sq Meters by 4042
    dAreaAcres = dArea / SQ_METERS_IN_ACRES
    dPerim = pGeometry.Length
    dRoundedness = (35.4 * (math.sqrt(dArea) / dPerim))
    dConservationValue = pRow.GetValue(sValueField)
                    
    if (dAreaAcres < 9):
        dAreaRank = 1
    elif (dAreaAcres>=9) and (dAreaAcres<14):
        dAreaRank = 2
    elif (dAreaAcres>=14) and (dAreaAcres<19):
        dAreaRank = 3
    elif (dAreaAcres>=19) and (dAreaAcres<26):
        dAreaRank = 4
    elif (dAreaAcres>=26) and (dAreaAcres<36):
        dAreaRank = 5
    elif (dAreaAcres>=36) and (dAreaAcres<50):
        dAreaRank = 6
    elif (dAreaAcres>=50) and (dAreaAcres<73):
        dAreaRank = 7
    elif (dAreaAcres>=73) and (dAreaAcres<122):
        dAreaRank = 8
    elif (dAreaAcres>=122) and (dAreaAcres<260):
        dAreaRank = 9
    elif (dAreaAcres>=260):
        dAreaRank = 10
    
    pRow.SetValue(sAreaMetersField,dArea)
    pRow.SetValue(sAreaAcresField,dAreaAcres)
    pRow.SetValue(sRoundednessField,dRoundedness)
    pRow.SetValue(sAreaRankField,dAreaRank)
    pRow.SetValue(sResultsField,((dConservationValue * CONS_VALUE_WEIGHT) + (dAreaRank * AREA_WEIGHT) + (dRoundedness * ROUNDEDNESS_WEIGHT)))
    pRows.UpdateRow(pRow)
    pRow = pRows.Next()
pGeometry = None
pRow = None
pRows = None
pGP = None
sInputFC = None
sOutputFC = None
#==========================================================================