'''
JMK Engineering Inc. Python Library for design and such.
by: Jeff MacKinnon

email: jeff@jmkengineering.com

Circuit Design Functions

'''
import pandas as pd
import numpy as np
import math
import sqlite3


def vd(current,length,resistance,runs=1):

    '''
        Calculates the voltage drop across the conductor length.

        If there are parallel runs we assume that they are approximately the same length.
        Therefore from the general equation of:

        1/Req = 1/R1 + 1/R2 ... and all R1-Rn are the same.
        Req = R/n or in the equation below r = resistance  / runs.
    '''

    r = (length*resistance/1000) / runs
    vd=round(2*current*r,8)
    return vd

def percentvd(vd,nominal):

    percent = (vd/nominal)*100
    return percent


def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', num_runs = 1, code = 'CEC'):

    '''    
    This function will return the drop in voltage and in percent of the supply.

    nominal_voltage = int
    current = float
    conductor_size = string

    Voltage drop equation is:
    
    Vdrop = 2 * I * L * R/1000
    
    I = load current
    L = circuit length in meters
    R = Resistance in ohms/km
    
    '''

    # Check to see if the db we need exists

    import os
    import sys
    if os.path.isfile('jepl-cable.db') == False:
        return (print("Run init. \nCopy jeplinit.py to the same folder as this file and add \n%run jeplinit.py jepl/folder/location/\nto the notebook. Make sure there is a trailing slash."))

    if (material == 'al'):

        try:
            with sqlite3.connect("jepl-cable.db") as con:
                cur = con.cursor()
                cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25051" WHERE "Conductor Number" = 3 AND "Conductor Size"=?', (conductor_size,))
                resistance = cur.fetchone()[0]
            
            #print(resistance)
                    
        except sqlite3.OperationalError as e:
            print(e)
    
    elif (material == 'cu'):
        try:
            with sqlite3.connect("jepl-cable.db") as con:
                cur = con.cursor()
                cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25055" WHERE "Conductor Number" = 3 AND "Conductor Size"=?', (conductor_size,))
                resistance = cur.fetchone()[0]
                    
        except sqlite3.OperationalError as e:
            print(e)

    else:
        return (print("error, choose material as cu or al"))

    voltage = vd(nominal_voltage,current,resistance,num_runs)
    percent = percentvd(voltage,nominal_voltage)

    return [voltage, percent]
#
# voltage_drop_conductors is wrong
#
#
def voltage_drop_conductors(voltage,current,distance,v_drop_percent = 0.03,runs = 1,material='cu'):
    '''
        Calculates the minimum conductor size to accomodate for voltage drop based on:

        voltage -> system nominal voltage
        current -> the peak/design load for the circuit
        distance -> meters
        v_drop_percent -> The design voltage drop (default 0.03 or 3%)
        runs -> number of parallel runs (default 1)
        material -> the conductor material, either 'al' or 'cu'. (default 'cu')

        First we calculate the necessary resistivity:

        resistivity = ohms/km
        but the distance is 2x (there and back)
        resistivity = ohms/[(2 * distance)/1000] {ohms/km}
        ohms = v/I or v_drop_percent/current

        resistivity = (v_drop_percent/current)/[(2 * distance)/1000]

        This works for 1 run, but for parallel runs Rtot = R/n where n is the number of runs.
        in this equation we are looking for R, not Rtot, so we multiply the top by the number of runs.

        therefore:
        resistivity = [(v_drop_percent/current)*runs]/[(2 * distance)/1000]

    '''

    # Determine the resistivity needed in ohms/km
    resistivity = ((v_drop_percent/current)*runs)/((2 * distance)/1000) 
    if resistivity < 0.1214:
        print("add parallel runs")
        print(resistivity)
    else:
        print(resistivity)

    import os
    import sys
    if os.path.isfile('jepl-cable.db') == False:
        return (print("Run init. \nCopy jeplinit.py to the same folder as this file and add \n%run jeplinit.py jepl/folder/location/\nto the notebook. Make sure there is a trailing slash."))

    # Lookup the conductor size that meets this resistivity.

    if (material == 'al'):

        try:
            with sqlite3.connect("jepl-cable.db") as con:
                cur = con.cursor()
                cur.execute('SELECT "Conductor Size" FROM "SW-Spec 25055" WHERE "Conductor Number" = 3 AND "AC Resistance"<?', (resistivity,))
                conductor = cur.fetchone()[0]
            
            print(conductor)
                    
        except sqlite3.OperationalError as e:
            print(e)
    
    elif (material == 'cu'):
        try:
            with sqlite3.connect("jepl-cable.db") as con:
                cur = con.cursor()
                cur.execute('SELECT "Conductor Size" FROM "SW-Spec 25051" WHERE "Conductor Number" = 3 AND "AC Resistance"<?', (resistivity,))
                conductor = cur.fetchone()[0]

            print(conductor)
                    
        except sqlite3.OperationalError as e:
            print(e)

    else:
        return (print("error, choose material as cu or al"))

    return (conductor)

# These functions need to be re-written with the databases. 

'''
'''
def conductor_size(current, temp = 75, material = 'cu', code = 'CEC', raceway = True, ambient = 30, max = 500):

    '''
    The default temp column will be the 75C column as most terminals are rated for this.
    The default code is CEC as that is where I am.

    I still need to incorporate ambient temperature deratings, but that will be a future improvement

    '''

    material = material.upper()
    code = code.upper()
    max = str(max)
    valid_temp = [60,75,90]
    valid_temp_str = [str(x) for x in valid_temp]
    valid_code = ['CEC', 
    ]
    valid_material = ['CU',
                      'AL',
    ]

    #check to make sure that the values are valid
    if temp not in valid_temp:
        return print(temp + " is not valid. The valid temps are "+ str(valid_temp_str))
    if code not in valid_code:
        return print(code + " is not a valid code. The valid codes are "+ str(valid_code))
    if material not in valid_material:
        return print(material + " is not a valid material. I should be 'al' or 'cu'.")

    # select the correct code table
    if (code == 'CEC') & (material == 'CU') & (raceway == False):
        code_table = CEC_table1
    elif (code == 'CEC') & (material == 'CU') & (raceway == True):
        code_table = CEC_table2
    elif (code =='CEC') & (material =='AL') & (raceway == False):
        code_table = CEC_table3
    elif (code =='CEC') & (material =='AL') & (raceway == True):
        code_table = CEC_table4
    elif (code =='NEC') & (material =='CU'):
        return (' I haven\'t created this table yet')
    elif (code =='NEC') & (material =='AL'):
        return (' I haven\'t created this table yet')
    else:
        return ('The variables were\'t right, but I\'m a loss to why.')
    
    temp = str(temp)
    
    max_current_loc = code_table.loc[code_table['size'] == max][str(temp)]
    max_current = max_current_loc.iloc[0]

    num_parallel = math.ceil(current / max_current) 
    con_current = current / num_parallel
 
    size = code_table[code_table[temp].ge(con_current)]['size'].iloc[0]

    return [size,num_parallel]
'''
'''
# ^
# These functions need to be re-written with the databases. 

'''
'''