commit 42a0efff1831bd135f05d5b635d24999dfe7bfb5
Author: Giov4 <brancacciogiovanni1@gmail.com>
Date:   Thu Mar 4 11:33:20 2021 +0100

    Initial commit

diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..718f019
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,92 @@
+currencies = {}
+local function save_database() end
+local function get_database() end
+local function validate_currency() end
+
+local storage = minetest.get_mod_storage()
+local registered_currencies = {}
+
+
+function currencies.register(currency)
+    registered_currencies[currency] = true
+end
+
+
+
+function currencies.set(pl_name, currency, value)
+    validate_currency(currency)
+
+    local db = get_database()
+    db[pl_name] = db[pl_name] or {}
+    db[pl_name][currency] = value
+
+    save_database(db)
+end
+
+
+
+function currencies.add(pl_name, currency, value)
+    validate_currency(currency)
+
+    local db = get_database()
+    db[pl_name] = db[pl_name] or {}
+    db[pl_name][currency] = db[pl_name][currency] or 0
+    db[pl_name][currency] = db[pl_name][currency] + value
+
+    save_database(db)
+end
+
+
+
+function currencies.sub(pl_name, currency, value)
+    validate_currency(currency)
+
+    local db = get_database()
+    db[pl_name] = db[pl_name] or {}
+    db[pl_name][currency] = db[pl_name][currency] or 0
+    db[pl_name][currency] = db[pl_name][currency] - value
+
+    save_database(db)
+end
+
+
+
+function currencies.get(pl_name, currency)
+    validate_currency(currency)
+    
+    local db = get_database()
+    db[pl_name] = db[pl_name] or {}
+    db[pl_name][currency] = db[pl_name][currency] or 0
+    
+    return db[pl_name][currency]
+end
+
+
+
+function save_database(value)
+    storage:set_string("database", minetest.serialize(value))
+end
+
+
+
+--[[
+    database = {
+        pl_name : string = {
+            currency_1 : string = value : number, 
+            ...
+        },
+        ...
+    }
+]]
+function get_database()
+    return minetest.deserialize(storage:get_string("database")) or {}
+end
+
+
+
+function validate_currency(currency)
+    assert(
+        registered_currencies[currency], 
+        "A mod is trying to access to the " .. currency .. " currency, but it hasn't been registered."
+    )
+end
\ No newline at end of file
diff --git a/mod.conf b/mod.conf
new file mode 100644
index 0000000..df0d981
--- /dev/null
+++ b/mod.conf
@@ -0,0 +1,2 @@
+name = currencies
+description = A simple API to register and manage currencies.
\ No newline at end of file