margin test

crates/api_clients/artcraft/artcraft_router/src/generate/generate_video_v2/providers/artcraft/grok_imagine_video/cost.rs

@@ -231,6 +231,176 @@ mod tests {
     }
   }
 
+  // ── Cross-provider margin: ArtCraft is consistently ~30% above GrokApi ──
+
+  mod small_margin {
+    use super::*;
+    use crate::api::common_aspect_ratio::CommonAspectRatio;
+
+    #[test]
+    fn small_margin() {
+      let resolutions = [
+        None,
+        Some(CommonResolution::FourEightyP),
+        Some(CommonResolution::SevenTwentyP),
+        Some(CommonResolution::TenEightyP), // clamps to 720p on both sides
+      ];
+      let durations: &[u16] = &[1, 4, 5, 8, 10, 12, 15];
+      let aspect_ratios = [
+        None,
+        Some(CommonAspectRatio::Auto),
+        Some(CommonAspectRatio::Square),
+        Some(CommonAspectRatio::WideSixteenByNine),
+        Some(CommonAspectRatio::TallNineBySixteen),
+        Some(CommonAspectRatio::WideFourByThree),
+        Some(CommonAspectRatio::TallThreeByFour),
+        Some(CommonAspectRatio::WideThreeByTwo),
+        Some(CommonAspectRatio::TallTwoByThree),
+      ];
+      // (has_start_frame, num_reference_images). At most one of the two is
+      // non-default — start_frame and reference_images are mutually exclusive
+      // on the GrokApi wire (image-to-video vs reference-to-video), so we
+      // don't mix them here to keep the comparison apples-to-apples.
+      let image_combos: &[(bool, usize)] = &[
+        (false, 0),  // text-to-video
+        (true,  0),  // image-to-video, 1 source image
+        (false, 1),  // reference-to-video, 1 ref image
+        (false, 2),
+        (false, 3),
+      ];
+
+      let mut total_cases = 0;
+      let mut failures = Vec::new();
+
+      for &res in &resolutions {
+        for &dur in durations {
+          for &ar in &aspect_ratios {
+            for &(has_start, num_refs) in image_combos {
+              total_cases += 1;
+              let artcraft = artcraft_cents(res, dur, ar, has_start, num_refs);
+              let grokapi  = grokapi_cents(res, dur, ar, has_start, num_refs);
+
+              // Margin requirement: artcraft / max(grokapi - 1, 1) >= 1.29.
+              // The (-1, 1) floor accounts for one cent of GrokApi-side
+              // ceiling-rounding noise (see test doc comment above).
+              let grokapi_compare = grokapi.saturating_sub(1).max(1);
+              let lhs = artcraft.saturating_mul(100);
+              let rhs = grokapi_compare.saturating_mul(129);
+
+              if lhs < rhs {
+                let pct = if grokapi == 0 { 0.0 }
+                  else { (artcraft as f64 / grokapi as f64 - 1.0) * 100.0 };
+                failures.push(format!(
+                  "res={:?} dur={}s ar={:?} start={} refs={} → \
+                   artcraft={}¢ vs grokapi={}¢ (margin {:.1}%, want ≥ 29% after 1¢ tolerance)",
+                  res, dur, ar, has_start, num_refs, artcraft, grokapi, pct,
+                ));
+              }
+
+              // Defense in depth: ArtCraft must always cost at least as
+              // much as GrokApi, regardless of rounding noise.
+              assert!(
+                artcraft >= grokapi,
+                "ArtCraft ({artcraft}¢) cheaper than GrokApi ({grokapi}¢) for \
+                 res={res:?} dur={dur}s ar={ar:?} start={has_start} refs={num_refs}",
+              );
+            }
+          }
+        }
+      }
+
+      if !failures.is_empty() {
+        let summary = failures.iter().take(10).cloned().collect::<Vec<_>>().join("\n  ");
+        panic!(
+          "{} / {} (res × duration × aspect × image_combo) tuples failed \
+           the ≥29% (with 1¢ tolerance) margin check.\nFirst 10:\n  {}",
+          failures.len(), total_cases, summary,
+        );
+      }
+    }
+
+    // ── Cross-provider helpers ──
+
+    fn artcraft_cents(
+      resolution: Option<CommonResolution>,
+      duration_seconds: u16,
+      aspect_ratio: Option<CommonAspectRatio>,
+      has_start_frame: bool,
+      num_reference_images: usize,
+    ) -> u64 {
+      let start_frame = if has_start_frame {
+        // ArtCraft's omni endpoint takes MediaFileTokens for image refs.
+        Some(ImageRef::MediaFileToken(MediaFileToken::new("mf_start".to_string())))
+      } else { None };
+      let reference_images = if num_reference_images > 0 {
+        Some(ImageListRef::MediaFileTokens(
+          (0..num_reference_images)
+            .map(|i| MediaFileToken::new(format!("mf_ref_{i}")))
+            .collect(),
+        ))
+      } else { None };
+
+      let builder = GenerateVideoRequestBuilder {
+        model: CommonVideoModel::GrokImagineVideo,
+        provider: Provider::Artcraft,
+        resolution,
+        aspect_ratio,
+        duration_seconds: Some(duration_seconds),
+        // Batch is fixed at 1 because GrokApi's per-request cost calculator
+        // doesn't multiply by batch (Grok returns one video per call); the
+        // markup test would compare apples to oranges otherwise.
+        video_batch_count: Some(1),
+        start_frame,
+        reference_images,
+        ..Default::default()
+      };
+      builder.build2()
+        .expect("build2 (artcraft) should succeed")
+        .estimate_cost()
+        .expect("estimate_cost (artcraft) should succeed")
+        .cost_in_usd_cents
+        .unwrap()
+    }
+
+    fn grokapi_cents(
+      resolution: Option<CommonResolution>,
+      duration_seconds: u16,
+      aspect_ratio: Option<CommonAspectRatio>,
+      has_start_frame: bool,
+      num_reference_images: usize,
+    ) -> u64 {
+      let start_frame = if has_start_frame {
+        // GrokApi (direct xAI) takes URLs for image refs.
+        Some(ImageRef::Url("https://example.com/start.png".to_string()))
+      } else { None };
+      let reference_images = if num_reference_images > 0 {
+        Some(ImageListRef::Urls(
+          (0..num_reference_images)
+            .map(|i| format!("https://example.com/ref_{i}.png"))
+            .collect(),
+        ))
+      } else { None };
+
+      let builder = GenerateVideoRequestBuilder {
+        model: CommonVideoModel::GrokImagineVideo,
+        provider: Provider::GrokApi,
+        resolution,
+        aspect_ratio,
+        duration_seconds: Some(duration_seconds),
+        video_batch_count: Some(1),
+        start_frame,
+        reference_images,
+        ..Default::default()
+      };
+      builder.build2()
+        .expect("build2 (grokapi) should succeed")
+        .estimate_cost()
+        .expect("estimate_cost (grokapi) should succeed")
+        .cost_in_usd_cents
+        .unwrap()
+    }
+  }
+
   // ── Helpers ──
 
   fn build_cost(