feat: add gacha credits

imphnen-gacha/src/v1/gacha_rolls/gacha_rolls_repository.rs

@@ -0,0 +1,79 @@
+use super::GachaRollQueryDto;
+use super::GachaRollSchema;
+use crate::{AppState, DetailQueryBuilder, ResourceEnum};
+use anyhow::{Result, bail};
+use imphnen_iam::ListQueryBuilder;
+use rand::prelude::*;
+use rand::rng;
+use rand_distr::weighted::WeightedIndex;
+
+pub struct GachaRollRepository<'a> {
+	state: &'a AppState,
+}
+
+impl<'a> GachaRollRepository<'a> {
+	pub fn new(state: &'a AppState) -> Self {
+		Self { state }
+	}
+
+	pub async fn query_gacha_roll_by_id(
+		&self,
+		id: String,
+	) -> Result<GachaRollQueryDto> {
+		let db = &self.state.surrealdb_ws;
+		let builder = DetailQueryBuilder::new(ResourceEnum::GachaRolls.to_string())
+			.with_id(id.clone())
+			.with_select_fields(vec!["*"])
+			.with_fetch("item");
+		let sql = builder.build();
+		let result: Option<GachaRollQueryDto> =
+			builder.apply_bindings(db.query(sql)).await?.take(0)?;
+		match result {
+			Some(roll) if !roll.is_deleted => Ok(roll),
+			_ => bail!("Gacha Roll not found"),
+		}
+	}
+
+	pub async fn query_create_gacha_roll(
+		&self,
+		data: GachaRollSchema,
+	) -> Result<String> {
+		let db = &self.state.surrealdb_ws;
+		let record: Option<GachaRollSchema> = db
+			.create(ResourceEnum::GachaRolls.to_string())
+			.content(data)
+			.await?;
+		match record {
+			Some(_) => Ok("Success create Gacha Roll".into()),
+			None => bail!("Failed to create Gacha Roll"),
+		}
+	}
+
+	pub async fn query_all_active_rolls(&self) -> Result<Vec<GachaRollQueryDto>> {
+		let db = &self.state.surrealdb_ws;
+		let builder = ListQueryBuilder::new(ResourceEnum::GachaRolls.to_string())
+			.with_select_fields(vec!["*"])
+			.with_fetch(Some(vec!["item"]));
+		let sql = builder.build();
+		let result: Vec<GachaRollQueryDto> = db.query(sql).await?.take(0)?;
+		Ok(result)
+	}
+
+	pub fn roll_once(rolls: &[GachaRollQueryDto]) -> Option<GachaRollQueryDto> {
+		let filtered: Vec<_> = rolls
+			.iter()
+			.filter(|r| !r.is_deleted && r.quantity > 0)
+			.collect();
+		let weights: Vec<f32> = filtered
+			.iter()
+			.map(|r| r.weight * r.quantity as f32)
+			.collect();
+		if weights.iter().all(|&w| w <= 0.0) {
+			return None;
+		}
+		let dist = WeightedIndex::new(&weights).ok()?;
+		let mut rng = rng();
+		let index = dist.sample(&mut rng);
+		Some(filtered[index].clone())
+	}
+}