[Tokenomics 2.0] Max vs. Realized Inflation Display

[Dinonard]

By doing a few simple data fetches, it's possible to show maximum vs. realized inflation.

1. Identify New Cycle Start & Max Inflation

When an event from pallet `Inflation, NewInflationConfiguration is emitted, it means a new cycle has started.

A snapshot of the total issuance is taken, and reward pools for the next cycle are calculated based on inflation parameters.
To replicate this, take the block BEFORE this even has happened, and calculate the max possible inflation.

first_block_in_the_cycle = <block at which event was detected>;
init_total_issuance = query.balances.totalIssuance();
max_inflation_rate = query.inflation.config.maxInflationRate();
max_inflation = init_total_issuance * max_inflation_rate;

2. Plot Max Inflation Line

The assumption here is that the max inflation rate will be linearly spread over the entire cycle.
X-axis contains blocks, while Y-axis contains total issuance.

The math is fairly simple:

cycle_length_in_blocks = <use runtime API to read this>;

cycle_progression = (x - first_block_in_the_cycle ) / cycle_length_in_blocks; // How much cycle has progressed, always between 0 and 1.
max_inflation(x) = cycle_progression * max_inflation + init_total_issuance;

where x is the block number.

3. Plot Realized Inflation Line

This one is also fairly simple.

At any block within the cycle, we simply read the total issuance:

current_block = ...;
realized_total_issuance = query.balances.totalIssuance();

Using this number, and knowing the values from the 1st subchapter above, we can estimate the final inflation:

cycle_length_in_blocks = <use runtime API to read this>;
cycle_progression = (x - first_block_in_the_cycle ) / cycle_length_in_blocks; // How much cycle has progressed, always between 0 and 1.

slope = (realized_total_issuance - init_total_issuance) / (x - first_block_in_the_cycle);

realized_inflation(x) = (x - first_block_in_the_cycle) * slope + init_total_issuance;

where x is the block number.

4. Expected Result