# @name Currency Market
# @desc Global currency exchange rate display
# @author Avemer
# @version 1.2

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 GAP

# INTERNAL VARIABLES
var result
var oldPrice
var comparisonPrice
var currentPriceTicks
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
self.PRICE_DECIMALS = 3

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

# PRICE COLOR MODE
# 0 = always white
# 1 = custom PRICE_COLOR
# 2 = automatic green/red comparison
# Automatic mode compares the newest rate
# with the most recent different rate found
# in the 5-day history.
self.PRICE_COLOR_MODE = 2

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

# CURRENT PRICE UPDATE
# Number of loop ticks between history requests.
# The first request is made immediately.
self.CURRENT_PRICE_UPDATE_TICKS = 600

# DISTANCE BETWEEN TICKER AND PRICE
self.GAP = 2
# ================ END OF USER SETTINGS ================
# INITIAL VALUES
self.result = "..."

# Newest rate from the API.
self.oldPrice = 0

# Previous rate that is different from the newest rate.
self.comparisonPrice = 0

# Countdown until the next API request.
self.currentPriceTicks = 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 DATE WITH OFFSET
# offset = 0 -> today
# offset = 1 -> yesterday
# offset = 5 -> five days ago
def get_previous_date(offset)

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

var i = 0

while i < offset

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

i += 1

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

# No different historical price was found.
if self.comparisonPrice <= 0

self.color = 0xFFFFFF
return

end

# Current price is higher than the previous

# different price -> green.

if self.oldPrice > self.comparisonPrice

self.color = 0x00FF00

# Current price is lower than the previous
# different price -> red.
elif self.oldPrice < self.comparisonPrice

self.color = 0xFF0000

else

self.color = 0xFFFFFF

end

end

# FORMAT PRICE
def format_price(value)

var s = str(value)

# 0 DECIMAL PLACES
if self.PRICE_DECIMALS <= 0

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

if p == nil
return "..."
end

return p[0]

end

# 1 DECIMAL PLACE
if self.PRICE_DECIMALS == 1

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

if p == nil
return "..."
end

return p[0]

end

# 2 DECIMAL PLACES
if self.PRICE_DECIMALS == 2

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

if p == nil
return "..."
end

return p[0]

end

# 3 DECIMAL PLACES
if self.PRICE_DECIMALS == 3

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

if p == nil
return "..."
end

return p[0]

end

# 4 DECIMAL PLACES
if self.PRICE_DECIMALS == 4

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

if p == nil
return "..."
end

return p[0]

end

# 5 OR MORE DECIMAL PLACES
return s

end

# PROCESS HISTORY RESPONSE
def on_rates(w, st)

if w == nil

return

end

# FIND ALL RATE VALUES
# The API response contains several dates.
# Example:
# 82.18
# 82.44
# 82.44
# The newest value is used as the current price.
# Then the history is searched for the newest value
# that is actually different from the current price.
var search = w
var firstPrice = 0
var lastPrice = 0
var foundCount = 0

var i = 0

while i < 10

var p = re.search(
"rate[^0-9]*([0-9]+[.][0-9]+)",
search
)

if p == nil

break

end

var value = num(p[1])

if value == nil

break

end

if foundCount == 0

firstPrice = value

end

lastPrice = value
foundCount += 1

if foundCount >= 10

break

end

# Search for the next rate.
var second = re.search(
"rate[^0-9]*[0-9]+[.][0-9]+.*rate[^0-9]*([0-9]+[.][0-9]+)",
search
)

if second == nil

break

end

var nextValue = num(second[1])

if nextValue == nil

break

end

lastPrice = nextValue
foundCount += 1

if foundCount >= 10

break

end

search = second[0]

i += 1

end

# NO VALID DATA
if foundCount <= 0

return

end

# CURRENT PRICE
self.oldPrice = lastPrice
self.result = self.format_price(lastPrice)

# FIND LAST DIFFERENT PRICE
# The newest value may occur on several consecutive days.
# Example:
# 2026-08-10 -> 82.18
# 2026-08-11 -> 82.44
# 2026-08-12 -> 82.44
# Current price = 82.44
# Comparison price = 82.18
# This prevents the current price from being compared
# with an identical value from the immediately previous day.
self.comparisonPrice = 0

var currentSearch = w
var attempts = 0

while attempts < 10

var q = re.search(
"rate[^0-9]*([0-9]+[.][0-9]+)",
currentSearch
)

if q == nil

break

end

var candidate = num(q[1])

if candidate == nil

break

end

# We found the newest rate that differs
# from the current rate.
if candidate != lastPrice

self.comparisonPrice = candidate
break

end

# Continue searching for an older rate.
var nextSearch = re.search(
"rate[^0-9]*[0-9]+[.][0-9]+.*rate[^0-9]*([0-9]+[.][0-9]+)",
currentSearch
)

if nextSearch == nil

break

end

currentSearch = nextSearch[0]
attempts += 1

end

# APPLY COLOR
self.update_color()

end

# MAIN LOOP
def loop()

self.currentPriceTicks -= 1

if self.currentPriceTicks <= 0

self.currentPriceTicks = self.CURRENT_PRICE_UPDATE_TICKS

# Request five days of historical rates at once.
# The API returns the rates chronologically.
# This allows the script to find the latest
# price that differs from the current one.
var fromDate = self.get_previous_date(5)
var toDate = self.get_previous_date(0)

http.get(
"https://api.frankfurter.dev/v2/rates?base=" + self.BASE_CURRENCY + "&quotes=" + self.QUOTE_CURRENCY + "&from=" + fromDate + "&to=" + toDate,
/ b, st -> self.on_rates(b, st)
)

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()