use brk_computer::Computer;
use brk_types::{DifficultyAdjustmentEntry, Epoch, Height};
use vecdb::{ReadableVec, Ro, VecIndex};
pub fn iter_difficulty_epochs(
computer: &Computer<Ro>,
start_height: usize,
end_height: usize,
) -> Vec<DifficultyAdjustmentEntry> {
let start_epoch = computer
.indexes
.height
.epoch
.collect_one(Height::from(start_height))
.unwrap_or_default();
let end_epoch = computer
.indexes
.height
.epoch
.collect_one(Height::from(end_height))
.unwrap_or_default();
let epoch_to_height = &computer.indexes.epoch.first_height;
let epoch_to_timestamp = &computer.indexes.timestamp.epoch;
let epoch_to_difficulty = &computer.blocks.difficulty.value.epoch;
let mut results = Vec::with_capacity(end_epoch.to_usize() - start_epoch.to_usize() + 1);
let mut prev_difficulty: Option<f64> = None;
for epoch_usize in start_epoch.to_usize()..=end_epoch.to_usize() {
let epoch = Epoch::from(epoch_usize);
let epoch_height = epoch_to_height.collect_one(epoch).unwrap_or_default();
if epoch_height.to_usize() < start_height {
prev_difficulty = epoch_to_difficulty.collect_one(epoch).map(|d| *d);
continue;
}
let epoch_timestamp = epoch_to_timestamp.collect_one(epoch).unwrap_or_default();
let epoch_difficulty = *epoch_to_difficulty.collect_one(epoch).unwrap_or_default();
let change_percent = match prev_difficulty {
Some(prev) if prev > 0.0 => ((epoch_difficulty / prev) - 1.0) * 100.0,
_ => 0.0,
};
results.push(DifficultyAdjustmentEntry {
timestamp: epoch_timestamp,
height: epoch_height,
difficulty: epoch_difficulty,
change_percent,
});
prev_difficulty = Some(epoch_difficulty);
}
results
}