fix(proxy): apply cost multiplier to total cost only

- Move multiplier calculation from per-item to total cost
- Add resolve_pricing_config for provider-level override
- Include request_model and cost_multiplier in usage logs
- Return new fields in get_request_logs API

src-tauri/src/proxy/usage/logger.rs

@@ -6,7 +6,7 @@ use crate::database::Database;
 use crate::error::AppError;
 use crate::services::usage_stats::find_model_pricing_row;
 use rust_decimal::Decimal;
-use std::time::SystemTime;
+use std::{str::FromStr, time::SystemTime};
 
 /// 请求日志
 #[derive(Debug, Clone)]
@@ -15,6 +15,7 @@ pub struct RequestLog {
     pub provider_id: String,
     pub app_type: String,
     pub model: String,
+    pub request_model: String,
     pub usage: TokenUsage,
     pub cost: Option<CostBreakdown>,
     pub latency_ms: u64,
@@ -73,17 +74,18 @@ impl<'a> UsageLogger<'a> {
 
         conn.execute(
             "INSERT INTO proxy_request_logs (
-                request_id, provider_id, app_type, model,
+                request_id, provider_id, app_type, model, request_model,
                 input_tokens, output_tokens, cache_read_tokens, cache_creation_tokens,
                 input_cost_usd, output_cost_usd, cache_read_cost_usd, cache_creation_cost_usd, total_cost_usd,
                 latency_ms, first_token_ms, status_code, error_message, session_id,
                 provider_type, is_streaming, cost_multiplier, created_at
-            ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13, ?14, ?15, ?16, ?17, ?18, ?19, ?20, ?21, ?22)",
+            ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13, ?14, ?15, ?16, ?17, ?18, ?19, ?20, ?21, ?22, ?23)",
             rusqlite::params![
                 log.request_id,
                 log.provider_id,
                 log.app_type,
                 log.model,
+                log.request_model,
                 log.usage.input_tokens,
                 log.usage.output_tokens,
                 log.usage.cache_read_tokens,
@@ -123,11 +125,13 @@ impl<'a> UsageLogger<'a> {
         error_message: String,
         latency_ms: u64,
     ) -> Result<(), AppError> {
+        let request_model = model.clone();
         let log = RequestLog {
             request_id,
             provider_id,
             app_type,
             model,
+            request_model,
             usage: TokenUsage::default(),
             cost: None,
             latency_ms,
@@ -160,11 +164,13 @@ impl<'a> UsageLogger<'a> {
         session_id: Option<String>,
         provider_type: Option<String>,
     ) -> Result<(), AppError> {
+        let request_model = model.clone();
         let log = RequestLog {
             request_id,
             provider_id,
             app_type,
             model,
+            request_model,
             usage: TokenUsage::default(),
             cost: None,
             latency_ms,
@@ -194,6 +200,96 @@ impl<'a> UsageLogger<'a> {
         }
     }
 
+    /// 获取有效的倍率与计费模式来源（供应商优先，未配置则回退全局默认）
+    pub async fn resolve_pricing_config(
+        &self,
+        provider_id: &str,
+        app_type: &str,
+    ) -> (Decimal, String) {
+        let default_multiplier_raw = match self.db.get_default_cost_multiplier(app_type).await {
+            Ok(value) => value,
+            Err(e) => {
+                log::warn!(
+                    "[USG-003] 获取默认倍率失败 (app_type={app_type}): {e}"
+                );
+                "1".to_string()
+            }
+        };
+        let default_multiplier = match Decimal::from_str(&default_multiplier_raw) {
+            Ok(value) => value,
+            Err(e) => {
+                log::warn!(
+                    "[USG-003] 默认倍率解析失败 (app_type={app_type}): {default_multiplier_raw} - {e}"
+                );
+                Decimal::from(1)
+            }
+        };
+
+        let default_pricing_source_raw = match self.db.get_pricing_model_source(app_type).await {
+            Ok(value) => value,
+            Err(e) => {
+                log::warn!(
+                    "[USG-003] 获取默认计费模式失败 (app_type={app_type}): {e}"
+                );
+                "response".to_string()
+            }
+        };
+        let default_pricing_source = if matches!(
+            default_pricing_source_raw.as_str(),
+            "response" | "request"
+        ) {
+            default_pricing_source_raw
+        } else {
+            log::warn!(
+                "[USG-003] 默认计费模式无效 (app_type={app_type}): {default_pricing_source_raw}"
+            );
+            "response".to_string()
+        };
+
+        let provider = self
+            .db
+            .get_provider_by_id(provider_id, app_type)
+            .ok()
+            .flatten();
+
+        let (provider_multiplier, provider_pricing_source) = provider
+            .as_ref()
+            .and_then(|p| p.meta.as_ref())
+            .map(|meta| {
+                (
+                    meta.cost_multiplier.as_deref(),
+                    meta.pricing_model_source.as_deref(),
+                )
+            })
+            .unwrap_or((None, None));
+
+        let cost_multiplier = match provider_multiplier {
+            Some(value) => match Decimal::from_str(value) {
+                Ok(parsed) => parsed,
+                Err(e) => {
+                    log::warn!(
+                        "[USG-003] 供应商倍率解析失败 (provider_id={provider_id}): {value} - {e}"
+                    );
+                    default_multiplier
+                }
+            },
+            None => default_multiplier,
+        };
+
+        let pricing_model_source = match provider_pricing_source {
+            Some(value) if matches!(value, "response" | "request") => value.to_string(),
+            Some(value) => {
+                log::warn!(
+                    "[USG-003] 供应商计费模式无效 (provider_id={provider_id}): {value}"
+                );
+                default_pricing_source.clone()
+            }
+            None => default_pricing_source.clone(),
+        };
+
+        (cost_multiplier, pricing_model_source)
+    }
+
     /// 计算并记录请求
     #[allow(clippy::too_many_arguments)]
     pub fn log_with_calculation(
@@ -202,6 +298,8 @@ impl<'a> UsageLogger<'a> {
         provider_id: String,
         app_type: String,
         model: String,
+        request_model: String,
+        pricing_model: String,
         usage: TokenUsage,
         cost_multiplier: Decimal,
         latency_ms: u64,
@@ -211,10 +309,12 @@ impl<'a> UsageLogger<'a> {
         provider_type: Option<String>,
         is_streaming: bool,
     ) -> Result<(), AppError> {
-        let pricing = self.get_model_pricing(&model)?;
+        let pricing = self.get_model_pricing(&pricing_model)?;
 
         if pricing.is_none() {
-            log::warn!("[USG-002] 模型定价未找到，成本将记录为 0");
+            log::warn!(
+                "[USG-002] 模型定价未找到，成本将记录为 0: {pricing_model}"
+            );
         }
 
         let cost = CostCalculator::try_calculate(&usage, pricing.as_ref(), cost_multiplier);
@@ -224,6 +324,7 @@ impl<'a> UsageLogger<'a> {
             provider_id,
             app_type,
             model,
+            request_model,
             usage,
             cost,
             latency_ms,
@@ -274,6 +375,8 @@ mod tests {
             "provider-1".to_string(),
             "claude".to_string(),
             "test-model".to_string(),
+            "req-model".to_string(),
+            "test-model".to_string(),
             usage,
             Decimal::from(1),
             100,
@@ -286,14 +389,15 @@ mod tests {
 
         // 验证记录已插入
         let conn = crate::database::lock_conn!(db.conn);
-        let count: i64 = conn
+        let (count, request_model): (i64, String) = conn
             .query_row(
-                "SELECT COUNT(*) FROM proxy_request_logs WHERE request_id = 'req-123'",
+                "SELECT COUNT(*), request_model FROM proxy_request_logs WHERE request_id = 'req-123'",
                 [],
-                |row| row.get(0),
+                |row| Ok((row.get(0)?, row.get(1)?)),
             )
             .unwrap();
         assert_eq!(count, 1);
+        assert_eq!(request_model, "req-model");
         Ok(())
     }