Add records mod to represent schema

1 files changed, 150 insertions, 0 deletions

diff --git a/src/app/store/records.rs b/src/app/store/records.rs
new file mode 100644
index 0000000..3f73765
--- /dev/null
+++ b/src/app/store/records.rs
@@ -0,0 +1,150 @@
+use bigdecimal::{BigDecimal, Context, RoundingMode};
+use std::sync::LazyLock;
+
+static ROUNDING_MODE: RoundingMode = RoundingMode::HalfEven;
+/// Will use default precision (either 100 or ${RUST_BIGDECIMAL_DEFAULT_PRECISION})
+static DECIMAL_CONTEXT: LazyLock<Context> = std::sync::LazyLock::new(|| Context::default().with_rounding_mode(ROUNDING_MODE));
+
+/// Represents an account that holds equity. An account may hold equity with
+/// multiple equity symbols.
+pub struct FiduciaryAccount {
+    pub fiduciary_account_id: u8,
+    pub fiduciary_account_number: usize,
+    pub fiduciary_account_name: String,
+    pub fiduciary_account_description: String,
+    pub fiduciary_account_created_timestamp: chrono::DateTime<chrono::Utc>,
+}
+
+/// An atomic enum to describe for what element of equity a symbol tracks
+/// (stock, fund, etc.)
+pub enum EquityType {
+    STOCK,
+    ETF,
+    CRYPTO
+}
+
+impl std::fmt::Display for EquityType {
+
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", match self {
+            EquityType::STOCK => "STOCK",
+            EquityType::ETF => "ETF",
+            EquityType::CRYPTO => "CRYPTO",
+        })
+    }
+
+}
+
+/// Represents a symbol used to ascribe speculative value
+pub struct EquitySymbol {
+    pub equity_symbol_id: usize,
+    pub equity_symbol_name: String,
+    pub equity_symbol_type: EquityType,
+    pub equity_symbol_managing_company: String,
+    pub equity_symbol_created_timestamp: chrono::DateTime<chrono::Utc>,
+}
+
+/// An atomic enum to describe the basic action of an equity change event
+pub enum ChangeEventType {
+    BUY,
+    SELL
+}
+
+impl ChangeEventType {
+
+    /// Relativizes the effect of a change event for numeration
+    pub fn score(&self) -> i8 {
+        match self {
+            ChangeEventType::BUY => 1,
+            ChangeEventType::SELL => -1,
+        }
+    }
+
+}
+
+impl std::fmt::Display for ChangeEventType {
+
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", match self {
+            ChangeEventType::BUY => "BUY",
+            ChangeEventType::SELL => "SELL",
+        })
+    }
+
+}
+
+/// An immutable record describing a quantative change for a symbolized
+/// equity attributed to an account.
+pub struct EquityChangeEvent {
+    pub equity_change_event_id: usize,
+    pub fiduciary_account_id: usize,
+    pub equity_symbol_id: usize,
+    pub equity_change_quantity: BigDecimal,
+    pub equity_change_cost_basis_usd: BigDecimal,
+    pub equity_change_type: ChangeEventType,
+    pub equity_change_timestamp: chrono::DateTime<chrono::Utc>,
+}
+
+impl EquityChangeEvent {
+
+    /// Provides an estimate of the numerated change based on the cost basis
+    /// of the equity and the quantity
+    pub fn estimated_price(&self) -> BigDecimal {
+        DECIMAL_CONTEXT.multiply(&self.equity_change_cost_basis_usd, &self.equity_change_quantity)
+    }
+
+}
+
+mod tests {
+    use super::*;
+    use std::str::FromStr;
+
+    fn nat(num: BigDecimal) -> BigDecimal {
+        num.with_scale_round(2_i64, ROUNDING_MODE)
+    }
+
+    #[test]
+    fn event_type_score_buy() {
+        let eventType = ChangeEventType::BUY;
+
+        assert_eq!(eventType.score(), 1_i8);
+    }
+
+    #[test]
+    fn event_type_score_sell() {
+        let eventType = ChangeEventType::SELL;
+
+        assert_eq!(eventType.score(), -1_i8);
+    }
+
+    #[test]
+    fn change_event_estimated_price() {
+        let event = EquityChangeEvent {
+            equity_change_event_id: 0,
+            fiduciary_account_id: 0,
+            equity_symbol_id: 0,
+            equity_change_quantity: BigDecimal::from_str("0.125").unwrap(),
+            equity_change_cost_basis_usd: BigDecimal::from_str("82.80").unwrap(),
+            equity_change_type: ChangeEventType::BUY,
+            equity_change_timestamp: chrono::Local::now().to_utc(),
+        };
+
+        assert_eq!(nat(event.estimated_price()).to_plain_string(), "10.35");
+    }
+
+    #[test]
+    fn change_event_estimated_price_rounded() {
+        let event = EquityChangeEvent {
+            equity_change_event_id: 0,
+            fiduciary_account_id: 0,
+            equity_symbol_id: 0,
+            equity_change_quantity: BigDecimal::from_str("87.12808").unwrap(),
+            equity_change_cost_basis_usd: BigDecimal::from_str("14.91").unwrap(),
+            equity_change_type: ChangeEventType::BUY,
+            equity_change_timestamp: chrono::Local::now().to_utc(),
+        };
+
+        // actual: 1299.0796728
+        assert_eq!(nat(event.estimated_price()).to_plain_string(), "1299.08");
+    }
+}
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