initial pass at handling non hardcoded reward emissions

file_store/src/emissions.rs

@@ -0,0 +1,105 @@
+use crate::Result;
+use chrono::{DateTime, Datelike, Utc};
+use rust_decimal::prelude::*;
+use rust_decimal_macros::dec;
+use serde::{Deserialize, Serialize};
+use std::{fs::File, io::Read};
+
+#[derive(Clone, Serialize, Deserialize, Debug)]
+pub struct Emission {
+    pub start_time: DateTime<Utc>,
+    pub yearly_emissions: Decimal,
+}
+
+#[derive(Clone, Serialize, Deserialize, Debug, Default)]
+pub struct EmissionsSchedule {
+    pub schedule: Vec<Emission>,
+}
+
+impl EmissionsSchedule {
+    pub fn from_json(json: &str) -> Result<Self> {
+        let emissions: Vec<Emission> = serde_json::from_str(json)?;
+        Ok(EmissionsSchedule {
+            schedule: emissions,
+        })
+    }
+
+    pub async fn from_file(filepath: String) -> Result<Self> {
+        let mut file = File::open(filepath)?;
+        let mut data = String::new();
+        file.read_to_string(&mut data)?;
+        let emissions: Vec<Emission> = serde_json::from_str(&data)?;
+        Ok(EmissionsSchedule {
+            schedule: emissions,
+        })
+    }
+
+    pub fn yearly_emissions(&self, datetime: DateTime<Utc>) -> Result<Decimal> {
+        let mut schedule = self.schedule.clone();
+        // todo: move sort to struct initialisation, having it here makes tests a lil easier for time being
+        schedule.sort_by(|a, b| b.start_time.cmp(&a.start_time));
+        let res = schedule
+            .into_iter()
+            .find(|emission| datetime >= emission.start_time)
+            .ok_or("failed to find emissions for specified date {datetime}")
+            .unwrap();
+        // return yearly emissions in bones
+        Ok(res.yearly_emissions * Decimal::from(1_000_000))
+    }
+
+    pub fn daily_emissions(&self, datetime: DateTime<Utc>) -> Result<Decimal> {
+        let cur_year = datetime.year();
+        let cur_month = datetime.month();
+        let num_days = num_days_this_period(cur_year, cur_month);
+        let yearly_emissions = self.yearly_emissions(datetime)?;
+        Ok(yearly_emissions / num_days)
+    }
+}
+
+fn num_days_this_period(year: i32, month: u32) -> Decimal {
+    if is_leap_epoch(year, month) {
+        dec!(366)
+    } else {
+        dec!(365)
+    }
+}
+
+fn is_leap_epoch(cur_year: i32, cur_month: u32) -> bool {
+    let next_year = cur_year + 1;
+    let is_current_year_a_leap = is_year_a_leap(cur_year) && cur_month < 8;
+    let is_next_year_a_leap = is_year_a_leap(next_year) && cur_month >= 8;
+    is_current_year_a_leap || is_next_year_a_leap
+}
+
+fn is_year_a_leap(year: i32) -> bool {
+    !(year % 4 != 0 || year % 100 == 0 && year % 400 != 0)
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_leap_year() {
+        assert!(!is_leap_epoch(2023, 7));
+        assert!(is_leap_epoch(2023, 8));
+        assert!(is_leap_epoch(2024, 7));
+        assert!(!is_leap_epoch(2024, 8));
+
+        assert!(!is_leap_epoch(2025, 1));
+        assert!(!is_leap_epoch(2025, 7));
+        assert!(!is_leap_epoch(2025, 8));
+        assert!(!is_leap_epoch(2026, 1));
+        assert!(!is_leap_epoch(2026, 7));
+        assert!(!is_leap_epoch(2026, 8));
+
+        assert!(!is_leap_epoch(2027, 7));
+        assert!(is_leap_epoch(2027, 8));
+        assert!(is_leap_epoch(2028, 7));
+        assert!(!is_leap_epoch(2028, 8));
+
+        assert!(!is_leap_epoch(2029, 1));
+        assert!(!is_leap_epoch(2029, 7));
+        assert!(!is_leap_epoch(2029, 8));
+    }
+}

file_store/src/error.rs

@@ -56,6 +56,8 @@ pub enum DecodeError {
     UnsupportedStatusReason(String, i32),
     #[error("invalid unix timestamp {0}")]
     InvalidTimestamp(u64),
+    #[error("json error")]
+    Json(#[from] serde_json::Error),
 }
 
 #[derive(Error, Debug)]

file_store/src/lib.rs

@@ -1,4 +1,5 @@
 pub mod cli;
+pub mod emissions;
 pub mod entropy_report;
 mod error;
 mod file_info;

iot_verifier/src/iot-ex1.json

@@ -0,0 +1,15 @@
+[
+    {
+      "start_time": "2022-08-01T00:00:01Z",
+      "yearly_emissions": 65000000000
+    },
+    {
+      "start_time": "2023-08-01T00:00:01Z",
+      "yearly_emissions": 32500000000
+    },
+    {
+        "start_time": "2024-08-01T00:00:01Z",
+        "yearly_emissions": 16250000000
+    }
+
+]