# @name Currency Market
# @desc Global currency exchange rate display
# @author Avemer
# @version 1.1
class CurrencyMarket

# USER VARIABLES
var BASE_CURRENCY
var QUOTE_CURRENCY
var TICKER_LETTERS
var PRICE_DECIMALS
var TICKER_COLOR
var PRICE_COLOR_MODE
var PRICE_COLOR
var CURRENT_PRICE_UPDATE_TICKS
var PREVIOUS_DAY_UPDATE_TICKS
var GAP

# INTERNAL VARIABLES
var result
var oldPrice
var previousDayPrice
var currentPriceTicks
var previousDayTicks
var color
var displayTICKER

# ================ START OF USER SETTINGS ================
def init()
  
# BASE CURRENCY
# Use a 3-letter ISO currency code.
# Examples:
# EUR, USD, GBP, JPY, CNY, CHF, RUB
self.BASE_CURRENCY = "EUR"

# QUOTE CURRENCY
# The currency in which the BASE currency is priced.
# Examples:
# EUR + USD = EUR/USD
# GBP + USD = GBP/USD
self.QUOTE_CURRENCY = "USD"

# NUMBER OF TICKER LETTERS DISPLAYED
# 0 = hide ticker
# 1 = first letter of BASE currency
# 2 = first two letters of BASE currency
# 3 = full BASE currency
# 4+ = full BASE/QUOTE pair
self.TICKER_LETTERS = 3

# NUMBER OF PRICE DECIMAL PLACES
# Controls how many digits are displayed
# after the decimal point.
# 0 = no decimal places
# 1 = one decimal place
# 2 = two decimal places
# 3 = three decimal places
# 4 = four decimal places
# Examples:
# PRICE_DECIMALS = 0
# USD 1
# PRICE_DECIMALS = 1
# USD 0.9
# PRICE_DECIMALS = 2
# USD 0.86
# PRICE_DECIMALS = 3
# USD 0.865
# PRICE_DECIMALS = 4
# USD 0.8650
self.PRICE_DECIMALS = 3

# TICKER COLOR
# Format: 0xRRGGBB
self.TICKER_COLOR = 0xFFFFFF

# PRICE COLOR MODE
# 0 = white
# 1 = custom PRICE_COLOR
# 2 = automatic green/red comparison
# Automatic mode compares the current rate
# with the previous calendar day's rate.
self.PRICE_COLOR_MODE = 2

# CUSTOM PRICE COLOR
# Used when PRICE_COLOR_MODE = 1.
self.PRICE_COLOR = 0xFFFFFF

# UPDATE INTERVALS
# CURRENT PRICE UPDATE
# Number of loop ticks between requests
# for the current exchange rate.
# The first request is made immediately
# when the script starts.
self.CURRENT_PRICE_UPDATE_TICKS = 600

# PREVIOUS DAY PRICE UPDATE
# Number of loop ticks between requests
# for the previous calendar day's exchange rate.
# This request is used only when
# PRICE_COLOR_MODE = 2.
self.PREVIOUS_DAY_UPDATE_TICKS = 610

# DISTANCE BETWEEN TICKER AND PRICE
self.GAP = 2
# ================ END OF USER SETTINGS ================

# INITIAL VALUES
self.result = "..."
self.oldPrice = 0
self.previousDayPrice = 0

# Start counters at zero.
# Because the loop decreases the counter
# before checking it, the first requests
# are made immediately.

self.currentPriceTicks = 0
self.previousDayTicks = 0

self.color = 0xFFFFFF
self.displayTICKER = ""

# CREATE DISPLAYED TICKER
if self.TICKER_LETTERS <= 0

self.displayTICKER = ""

elif self.TICKER_LETTERS == 1

self.displayTICKER = self.BASE_CURRENCY[0]

elif self.TICKER_LETTERS == 2

self.displayTICKER = self.BASE_CURRENCY[0] + self.BASE_CURRENCY[1]

elif self.TICKER_LETTERS == 3

self.displayTICKER = self.BASE_CURRENCY

else

self.displayTICKER = self.BASE_CURRENCY + "/" + self.QUOTE_CURRENCY

end

end

# GET PREVIOUS CALENDAR DATE
def get_previous_date()

var y = year()
var m = month()
var d = day()

d -= 1

if d <= 0

m -= 1

if m <= 0

m = 12
y -= 1
end

if m == 1
d = 31

elif m == 2
d = 28

elif m == 3
d = 31

elif m == 4
d = 30

elif m == 5
d = 31

elif m == 6
d = 30

elif m == 7
d = 31

elif m == 8
d = 31

elif m == 9
d = 30

elif m == 10
d = 31

elif m == 11
d = 30

else
d = 31

end

end

# LEAP YEAR CORRECTION
if m == 2

if d == 28

if y % 4 == 0

d = 29

end

end

end

var ms = str(m)
var ds = str(d)

if m < 10

ms = "0" + ms

end

if d < 10

ds = "0" + ds

end

return str(y) + "-" + ms + "-" + ds

end

# APPLY PRICE COLOR
def update_color()

if self.PRICE_COLOR_MODE == 0

self.color = 0xFFFFFF
return

end

if self.PRICE_COLOR_MODE == 1

self.color = self.PRICE_COLOR
return

end

if self.previousDayPrice <= 0

return

end

if self.oldPrice > self.previousDayPrice

self.color = 0x00FF00

elif self.oldPrice < self.previousDayPrice

self.color = 0xFF0000

else

self.color = 0xFFFFFF

end

end

# FORMAT CURRENT PRICE
# The script uses regular expressions to
# extract exactly the requested number of
# decimal places from the API response.
# This avoids unsupported string functions
# such as len() and split().
def format_price(w)

var p

# 0 DECIMAL PLACES
if self.PRICE_DECIMALS <= 0

p = re.search(
"[0-9]+",
w
)

if p == nil

return "..."
end

return p[0]

end

# 1 DECIMAL PLACE
if self.PRICE_DECIMALS == 1

p = re.search(
"[0-9]+[.][0-9]",
w
)

if p == nil

return "..."
end

return p[0]

end

# 2 DECIMAL PLACES
if self.PRICE_DECIMALS == 2

p = re.search(
"[0-9]+[.][0-9][0-9]",
w
)

if p == nil

return "..."
end

return p[0]

end

# 3 DECIMAL PLACES
if self.PRICE_DECIMALS == 3

p = re.search(
"[0-9]+[.][0-9][0-9][0-9]",
w
)

if p == nil

return "..."
end

return p[0]

end

# 4 DECIMAL PLACES
if self.PRICE_DECIMALS == 4

p = re.search(
"[0-9]+[.][0-9][0-9][0-9][0-9]",
w
)

if p == nil

return "..."
end

return p[0]

end

# 5 OR MORE DECIMAL PLACES
# Keep the original API value.
p = re.search(
"[0-9]+[.][0-9]+",
w
)

if p == nil

return "..."
end

return p[0]

end

# CURRENT PRICE RESPONSE
def on_price(w, st)

if w == nil

return

end

# Find the word "rate" in the response.
var m = re.search(
"rate",
w
)

if m == nil

return

end

# Extract the complete numeric rate
# for calculations and color comparison.
var p = re.search(
"[0-9]+[.][0-9]+",
w
)

if p == nil

return

end

var newPrice = num(p[0])

if newPrice == nil

return

end

# Store full numeric value internally.
self.oldPrice = newPrice

# Format only the displayed value.
self.result = self.format_price(w)

# Update price color.
self.update_color()

end

# PREVIOUS CALENDAR DAY RESPONSE
def on_previous_day(w, st)

if w == nil

return

end

# Find the word "rate" in the response.
var m = re.search(
"rate",
w
)

if m == nil

return

end

# Extract the numeric rate.
var p = re.search(
"[0-9]+[.][0-9]+",
w
)

if p == nil

return

end

var newPrice = num(p[0])

if newPrice == nil

return

end

self.previousDayPrice = newPrice

self.update_color()

end

# MAIN LOOP
def loop()

#CURRENT PRICE REQUEST
self.currentPriceTicks -= 1

if self.currentPriceTicks <= 0

self.currentPriceTicks = self.CURRENT_PRICE_UPDATE_TICKS

http.get(
"https://api.frankfurter.dev/v2/rate/" + self.BASE_CURRENCY + "/" + self.QUOTE_CURRENCY,
/ b, st -> self.on_price(b, st)
)

end

#PREVIOUS DAY REQUEST
if self.PRICE_COLOR_MODE == 2

self.previousDayTicks -= 1

if self.previousDayTicks <= 0

self.previousDayTicks = self.PREVIOUS_DAY_UPDATE_TICKS

var previousDate = self.get_previous_date()

http.get(
"https://api.frankfurter.dev/v2/rate/" + self.BASE_CURRENCY + "/" + self.QUOTE_CURRENCY + "?date=" + previousDate,
/ b, st -> self.on_previous_day(b, st)
)

end

end

end

# DRAW
def draw()

clear()

var tickerWidth = text_ink_width(self.displayTICKER)
var priceWidth = text_ink_width(self.result)

var totalWidth = tickerWidth + self.GAP + priceWidth

var x = int((width() - totalWidth) / 2)

if self.TICKER_LETTERS > 0

text(
x,
7,
self.displayTICKER,
self.TICKER_COLOR
)

end

text(
x + tickerWidth + self.GAP,
7,
self.result,
self.color
)

end

def on_button(btn)
end

end

return CurrencyMarket()