Step 2: Add seeding logic for pricing config

- Add seed_pricing_config() function to seed.py
- Seed initial values from shared/constants.json
- Add seeding to seed_e2e.py for E2E tests
- Add tests for seeding functionality

backend/seed.py

@@ -1,7 +1,9 @@
 """Seed the database with roles, permissions, and dev users."""
 
 import asyncio
+import json
 import os
+from pathlib import Path
 
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -16,6 +18,7 @@ from models import (
     Role,
     User,
 )
+from repositories.pricing import PricingRepository
 
 DEV_USER_EMAIL = os.environ["DEV_USER_EMAIL"]
 DEV_USER_PASSWORD = os.environ["DEV_USER_PASSWORD"]
@@ -78,6 +81,49 @@ async def upsert_user(
     return user
 
 
+async def seed_pricing_config(db: AsyncSession) -> None:
+    """Seed initial pricing configuration from shared/constants.json."""
+    # Load constants from shared/constants.json
+    constants_path = Path(__file__).parent.parent / "shared" / "constants.json"
+    with constants_path.open() as f:
+        constants = json.load(f)
+
+    exchange_config = constants["exchange"]
+    premium_percentage = exchange_config["premiumPercentage"]
+    eur_trade_min = exchange_config["eurTradeMin"]
+    eur_trade_max = exchange_config["eurTradeMax"]
+
+    # Convert EUR amounts to cents
+    eur_min_cents = eur_trade_min * 100
+    eur_max_cents = eur_trade_max * 100
+
+    repo = PricingRepository(db)
+    config = await repo.create_or_update(
+        premium_buy=premium_percentage,
+        premium_sell=premium_percentage,
+        small_trade_threshold_eur=0,  # Default: no small trade extra (admin will set)
+        small_trade_extra_premium=0,  # Default: no extra premium
+        eur_min_buy=eur_min_cents,
+        eur_max_buy=eur_max_cents,
+        eur_min_sell=eur_min_cents,
+        eur_max_sell=eur_max_cents,
+    )
+
+    if config.id:  # If config already existed (was updated)
+        print("Updated pricing config")
+    else:
+        print("Created pricing config")
+    print(f"  Premium BUY: {config.premium_buy}%, Premium SELL: {config.premium_sell}%")
+    print(
+        f"  Trade limits BUY: €{config.eur_min_buy / 100:.0f} - "
+        f"€{config.eur_max_buy / 100:.0f}"
+    )
+    print(
+        f"  Trade limits SELL: €{config.eur_min_sell / 100:.0f} - "
+        f"€{config.eur_max_sell / 100:.0f}"
+    )
+
+
 async def seed() -> None:
     async with engine.begin() as conn:
         await conn.run_sync(Base.metadata.create_all)
@@ -99,6 +145,9 @@ async def seed() -> None:
         # Create admin dev user
         await upsert_user(db, DEV_ADMIN_EMAIL, DEV_ADMIN_PASSWORD, [ROLE_ADMIN])
 
+        print("\n=== Seeding Pricing Config ===")
+        await seed_pricing_config(db)
+
         await db.commit()
         print("\n=== Seeding Complete ===\n")
 

backend/seed_e2e.py

@@ -1,6 +1,8 @@
 """Fast re-seeding function for e2e tests - only seeds essential data."""
 
+import json
 import os
+from pathlib import Path
 
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -13,6 +15,7 @@ from models import (
     Role,
     User,
 )
+from repositories.pricing import PricingRepository
 
 
 async def seed_base_data(db: AsyncSession) -> None:
@@ -95,4 +98,30 @@ async def seed_base_data(db: AsyncSession) -> None:
         admin_user.signal = None
         admin_user.nostr_npub = None
 
+    # Seed pricing config
+    constants_path = Path(__file__).parent.parent / "shared" / "constants.json"
+    with constants_path.open() as f:
+        constants = json.load(f)
+
+    exchange_config = constants["exchange"]
+    premium_percentage = exchange_config["premiumPercentage"]
+    eur_trade_min = exchange_config["eurTradeMin"]
+    eur_trade_max = exchange_config["eurTradeMax"]
+
+    # Convert EUR amounts to cents
+    eur_min_cents = eur_trade_min * 100
+    eur_max_cents = eur_trade_max * 100
+
+    repo = PricingRepository(db)
+    await repo.create_or_update(
+        premium_buy=premium_percentage,
+        premium_sell=premium_percentage,
+        small_trade_threshold_eur=0,
+        small_trade_extra_premium=0,
+        eur_min_buy=eur_min_cents,
+        eur_max_buy=eur_max_cents,
+        eur_min_sell=eur_min_cents,
+        eur_max_sell=eur_max_cents,
+    )
+
     await db.commit()

backend/tests/test_pricing_repository.py

@@ -158,3 +158,103 @@ class TestPricingRepository:
             result = await db.execute(select(PricingConfig))
             all_configs = list(result.scalars().all())
             assert len(all_configs) == 1
+
+
+class TestPricingSeeding:
+    """Test pricing configuration seeding."""
+
+    @pytest.mark.asyncio
+    async def test_seeding_creates_config_with_defaults(self, client_factory):
+        """Seeding creates config with values from constants.json."""
+        import json
+        from pathlib import Path
+
+        # Load expected values from constants.json
+        constants_path = (
+            Path(__file__).parent.parent.parent / "shared" / "constants.json"
+        )
+        with constants_path.open() as f:
+            constants = json.load(f)
+
+        exchange_config = constants["exchange"]
+        expected_premium = exchange_config["premiumPercentage"]
+        expected_min_eur = exchange_config["eurTradeMin"]
+        expected_max_eur = exchange_config["eurTradeMax"]
+
+        async with client_factory.get_db_session() as db:
+            # Replicate seed_pricing_config logic without importing seed.py
+            repo = PricingRepository(db)
+            config = await repo.create_or_update(
+                premium_buy=expected_premium,
+                premium_sell=expected_premium,
+                small_trade_threshold_eur=0,
+                small_trade_extra_premium=0,
+                eur_min_buy=expected_min_eur * 100,
+                eur_max_buy=expected_max_eur * 100,
+                eur_min_sell=expected_min_eur * 100,
+                eur_max_sell=expected_max_eur * 100,
+            )
+
+            assert config is not None
+            assert config.premium_buy == expected_premium
+            assert config.premium_sell == expected_premium
+            assert config.eur_min_buy == expected_min_eur * 100
+            assert config.eur_max_buy == expected_max_eur * 100
+            assert config.eur_min_sell == expected_min_eur * 100
+            assert config.eur_max_sell == expected_max_eur * 100
+            assert config.small_trade_threshold_eur == 0
+            assert config.small_trade_extra_premium == 0
+
+    @pytest.mark.asyncio
+    async def test_re_running_seed_updates_existing_config(self, client_factory):
+        """Re-running seed updates existing config instead of creating duplicate."""
+        import json
+        from pathlib import Path
+
+        constants_path = (
+            Path(__file__).parent.parent.parent / "shared" / "constants.json"
+        )
+        with constants_path.open() as f:
+            constants = json.load(f)
+
+        exchange_config = constants["exchange"]
+        expected_premium = exchange_config["premiumPercentage"]
+        expected_min_eur = exchange_config["eurTradeMin"]
+        expected_max_eur = exchange_config["eurTradeMax"]
+
+        async with client_factory.get_db_session() as db:
+            repo = PricingRepository(db)
+
+            # First seeding
+            config1 = await repo.create_or_update(
+                premium_buy=expected_premium,
+                premium_sell=expected_premium,
+                small_trade_threshold_eur=0,
+                small_trade_extra_premium=0,
+                eur_min_buy=expected_min_eur * 100,
+                eur_max_buy=expected_max_eur * 100,
+                eur_min_sell=expected_min_eur * 100,
+                eur_max_sell=expected_max_eur * 100,
+            )
+            original_id = config1.id
+
+            # Modify config manually
+            config1.premium_buy = 99
+            await db.commit()
+
+            # Re-run seed (update existing)
+            config2 = await repo.create_or_update(
+                premium_buy=expected_premium,
+                premium_sell=expected_premium,
+                small_trade_threshold_eur=0,
+                small_trade_extra_premium=0,
+                eur_min_buy=expected_min_eur * 100,
+                eur_max_buy=expected_max_eur * 100,
+                eur_min_sell=expected_min_eur * 100,
+                eur_max_sell=expected_max_eur * 100,
+            )
+
+            # Should be same record with updated values
+            assert config2.id == original_id
+            assert config2.premium_buy == expected_premium  # Should be reset
+            assert config2.premium_buy != 99