use chrono::{DateTime, TimeZone, Utc};
use crate::models::Usage;
struct ModelPricing {
input_cache_hit_per_million: f64,
input_cache_miss_per_million: f64,
output_per_million: f64,
}
fn v4_pro_discount_ends_at() -> DateTime<Utc> {
Utc.with_ymd_and_hms(2026, 5, 31, 15, 59, 0)
.single()
.expect("valid DeepSeek V4 Pro discount end timestamp")
}
fn pricing_for_model(model: &str) -> Option<ModelPricing> {
pricing_for_model_at(model, Utc::now())
}
fn pricing_for_model_at(model: &str, now: DateTime<Utc>) -> Option<ModelPricing> {
let lower = model.to_lowercase();
if lower.starts_with("deepseek-ai/") {
return None;
}
if !lower.contains("deepseek") {
return None;
}
if lower.contains("v4-pro") || lower.contains("v4pro") {
if now <= v4_pro_discount_ends_at() {
return Some(ModelPricing {
input_cache_hit_per_million: 0.003625,
input_cache_miss_per_million: 0.435,
output_per_million: 0.87,
});
}
Some(ModelPricing {
input_cache_hit_per_million: 0.0145,
input_cache_miss_per_million: 1.74,
output_per_million: 3.48,
})
} else {
Some(ModelPricing {
input_cache_hit_per_million: 0.0028,
input_cache_miss_per_million: 0.14,
output_per_million: 0.28,
})
}
}
#[must_use]
#[allow(dead_code)]
pub fn calculate_turn_cost(model: &str, input_tokens: u32, output_tokens: u32) -> Option<f64> {
let pricing = pricing_for_model(model)?;
Some(calculate_turn_cost_with_pricing(
pricing,
input_tokens,
output_tokens,
))
}
fn calculate_turn_cost_with_pricing(
pricing: ModelPricing,
input_tokens: u32,
output_tokens: u32,
) -> f64 {
let input_cost = (input_tokens as f64 / 1_000_000.0) * pricing.input_cache_miss_per_million;
let output_cost = (output_tokens as f64 / 1_000_000.0) * pricing.output_per_million;
input_cost + output_cost
}
#[must_use]
pub fn calculate_turn_cost_from_usage(model: &str, usage: &Usage) -> Option<f64> {
let pricing = pricing_for_model(model)?;
Some(calculate_turn_cost_from_usage_with_pricing(pricing, usage))
}
fn calculate_turn_cost_from_usage_with_pricing(pricing: ModelPricing, usage: &Usage) -> f64 {
let hit_tokens = usage.prompt_cache_hit_tokens.unwrap_or(0);
let miss_tokens = usage
.prompt_cache_miss_tokens
.unwrap_or_else(|| usage.input_tokens.saturating_sub(hit_tokens));
let accounted_input = hit_tokens.saturating_add(miss_tokens);
let uncategorized_input = usage.input_tokens.saturating_sub(accounted_input);
let hit_cost = (hit_tokens as f64 / 1_000_000.0) * pricing.input_cache_hit_per_million;
let miss_cost = ((miss_tokens.saturating_add(uncategorized_input)) as f64 / 1_000_000.0)
* pricing.input_cache_miss_per_million;
let output_cost = (usage.output_tokens as f64 / 1_000_000.0) * pricing.output_per_million;
hit_cost + miss_cost + output_cost
}
#[must_use]
#[allow(dead_code)]
pub fn format_cost(cost: f64) -> String {
if cost < 0.0001 {
"<$0.0001".to_string()
} else if cost < 0.01 {
format!("${:.4}", cost)
} else if cost < 1.0 {
format!("${:.3}", cost)
} else {
format!("${:.2}", cost)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn nvidia_nim_deepseek_model_does_not_use_deepseek_platform_pricing() {
assert!(calculate_turn_cost("deepseek-ai/deepseek-v4-pro", 1_000, 1_000).is_none());
}
#[test]
fn v4_pro_uses_limited_time_discount_before_expiry() {
let before_expiry = Utc
.with_ymd_and_hms(2026, 5, 31, 15, 58, 59)
.single()
.unwrap();
let pricing = pricing_for_model_at("deepseek-v4-pro", before_expiry).unwrap();
assert_eq!(pricing.input_cache_hit_per_million, 0.003625);
assert_eq!(pricing.input_cache_miss_per_million, 0.435);
assert_eq!(pricing.output_per_million, 0.87);
}
#[test]
fn v4_pro_returns_to_base_rates_after_discount_expiry() {
let after_expiry = Utc
.with_ymd_and_hms(2026, 5, 31, 16, 0, 0)
.single()
.unwrap();
let pricing = pricing_for_model_at("deepseek-v4-pro", after_expiry).unwrap();
assert_eq!(pricing.input_cache_hit_per_million, 0.0145);
assert_eq!(pricing.input_cache_miss_per_million, 1.74);
assert_eq!(pricing.output_per_million, 3.48);
}
#[test]
fn v4_pro_discount_still_applies_just_before_old_may5_expiry() {
let after_old_expiry = Utc.with_ymd_and_hms(2026, 5, 6, 0, 0, 0).single().unwrap();
let pricing = pricing_for_model_at("deepseek-v4-pro", after_old_expiry).unwrap();
assert_eq!(pricing.input_cache_hit_per_million, 0.003625);
assert_eq!(pricing.input_cache_miss_per_million, 0.435);
assert_eq!(pricing.output_per_million, 0.87);
}
#[test]
fn v4_flash_keeps_current_published_rates() {
let now = Utc.with_ymd_and_hms(2026, 4, 25, 0, 0, 0).single().unwrap();
let pricing = pricing_for_model_at("deepseek-v4-flash", now).unwrap();
assert_eq!(pricing.input_cache_hit_per_million, 0.0028);
assert_eq!(pricing.input_cache_miss_per_million, 0.14);
assert_eq!(pricing.output_per_million, 0.28);
}
}