# Review Comment

- **Author:** coderabbitai[bot]
- **File:** `packages/core/ai_content_platform/vimax/agents/screenwriter.py`
- **Line:** 136
- **Date:** 2026-02-03
- **Comment ID:** 2756929080
- **URL:** https://github.com/donghaozhang/video-agent-skill/pull/16#discussion_r2756929080

---

_⚠️ Potential issue_ | _🟠 Major_

<details>
<summary>🧩 Analysis chain</summary>

🏁 Script executed:

```shell
find . -type f -name "screenwriter.py" | head -20
```

Repository: donghaozhang/video-agent-skill

Length of output: 214

---

🏁 Script executed:

```shell
find . -type f -path "*/vimax/agents/screenwriter.py"
```

Repository: donghaozhang/video-agent-skill

Length of output: 138

---

🏁 Script executed:

```shell
git ls-files | grep -i screenwriter
```

Repository: donghaozhang/video-agent-skill

Length of output: 210

---

🏁 Script executed:

```shell
wc -l packages/core/ai_content_platform/vimax/agents/screenwriter.py
```

Repository: donghaozhang/video-agent-skill

Length of output: 140

---

🏁 Script executed:

```shell
sed -n '120,150p' packages/core/ai_content_platform/vimax/agents/screenwriter.py
```

Repository: donghaozhang/video-agent-skill

Length of output: 1044

---

🏁 Script executed:

```shell
head -50 packages/core/ai_content_platform/vimax/agents/screenwriter.py
```

Repository: donghaozhang/video-agent-skill

Length of output: 1384

---

🏁 Script executed:

```shell
grep -n "config" packages/core/ai_content_platform/vimax/agents/screenwriter.py | head -20
```

Repository: donghaozhang/video-agent-skill

Length of output: 677

---

🏁 Script executed:

```shell
find . -type f -name "base.py" -path "*/vimax/agents/*"
```

Repository: donghaozhang/video-agent-skill

Length of output: 130

---

🏁 Script executed:

```shell
grep -n "class AgentConfig" packages/core/ai_content_platform/vimax/agents/base.py | head -5
```

Repository: donghaozhang/video-agent-skill

Length of output: 106

---

🏁 Script executed:

```shell
sed -n '17,60p' packages/core/ai_content_platform/vimax/agents/base.py
```

Repository: donghaozhang/video-agent-skill

Length of output: 1400

---

🏁 Script executed:

```shell
grep -A 20 "class ScreenwriterConfig" packages/core/ai_content_platform/vimax/agents/screenwriter.py
```

Repository: donghaozhang/video-agent-skill

Length of output: 684

---

🏁 Script executed:

```shell
grep -n "validator\|root_validator\|field_validator" packages/core/ai_content_platform/vimax/agents/screenwriter.py
```

Repository: donghaozhang/video-agent-skill

Length of output: 56

---

🏁 Script executed:

```shell
grep -n "validator\|root_validator\|field_validator" packages/core/ai_content_platform/vimax/agents/base.py
```

Repository: donghaozhang/video-agent-skill

Length of output: 56

---

🏁 Script executed:

```shell
sed -n '1,50p' packages/core/ai_content_platform/vimax/agents/screenwriter.py | grep -A 10 "class ScreenwriterConfig"
```

Repository: donghaozhang/video-agent-skill

Length of output: 490

---

🏁 Script executed:

```shell
python3 << 'EOF'
# Check if Pydantic Field constraints are used in ScreenwriterConfig definition
import re

with open('packages/core/ai_content_platform/vimax/agents/screenwriter.py', 'r') as f:
    content = f.read()
    
# Find ScreenwriterConfig class
match = re.search(r'class ScreenwriterConfig\(.*?\):(.*?)(?=\nclass |\nSCREENPLAY_PROMPT|\Z)', content, re.DOTALL)
if match:
    config_class = match.group(1)
    print("ScreenwriterConfig definition:")
    print(config_class[:500])
    
    # Check for Field() calls with constraints
    if 'Field(' in config_class:
        print("\n[FOUND] Field constraints detected")
    else:
        print("\n[NOT FOUND] No Field() constraints - bare type hints only")
        
    # Check for validators
    if '@' in config_class and ('validator' in config_class or 'field_validator' in config_class):
        print("[FOUND] Validators detected")
    else:
        print("[NOT FOUND] No validators")
EOF
```

Repository: donghaozhang/video-agent-skill

Length of output: 453

---

🏁 Script executed:

```shell
cat -n packages/core/ai_content_platform/vimax/agents/screenwriter.py | sed -n '100,145p'
```

Repository: donghaozhang/video-agent-skill

Length of output: 1985

---

🏁 Script executed:

```shell
grep -B 5 -A 15 "class BaseAgent" packages/core/ai_content_platform/vimax/agents/base.py | head -40
```

Repository: donghaozhang/video-agent-skill

Length of output: 801

---

🏁 Script executed:

```shell
grep -n "__init__" packages/core/ai_content_platform/vimax/agents/base.py | head -5
```

Repository: donghaozhang/video-agent-skill

Length of output: 138

---

🏁 Script executed:

```shell
python3 << 'EOF'
# Test if Pydantic allows invalid values
from pydantic import BaseModel

class TestConfig(BaseModel):
    target_duration: float = 60.0
    shots_per_scene: int = 3

# Test with valid defaults
config1 = TestConfig()
print(f"Valid config: target_duration={config1.target_duration}, shots_per_scene={config1.shots_per_scene}")

# Test with invalid values (zero/negative)
try:
    config2 = TestConfig(target_duration=0, shots_per_scene=0)
    print(f"Invalid config allowed: target_duration={config2.target_duration}, shots_per_scene={config2.shots_per_scene}")
    
    # Now test the division
    avg_shot_duration = 5.0
    total_shots = config2.target_duration / avg_shot_duration
    print(f"total_shots = {total_shots}")
    
    # This will fail if shots_per_scene is 0
    num_scenes = max(1, int(total_shots / config2.shots_per_scene))
except ZeroDivisionError as e:
    print(f"ZeroDivisionError: {e}")
except Exception as e:
    print(f"Other error: {e}")
EOF
```

Repository: donghaozhang/video-agent-skill

Length of output: 250

---

🏁 Script executed:

```shell
grep -r "shots_per_scene\|target_duration" packages/core/ai_content_platform/vimax --include="*.py" | grep -E "(validate|check|assert|Guard)" | head -10
```

Repository: donghaozhang/video-agent-skill

Length of output: 56

---

🏁 Script executed:

```shell
# Check if there's a config validation method on BaseAgent or anywhere in the init chain
grep -B 2 -A 10 "def __init__" packages/core/ai_content_platform/vimax/agents/base.py
```

Repository: donghaozhang/video-agent-skill

Length of output: 505

---



</details>

**Guard against invalid config values to prevent ZeroDivisionError.**

The calculation on lines 134-135 will crash if `shots_per_scene` or `target_duration` is zero or negative. Pydantic does not prevent invalid values by default, so explicit validation is necessary. Add checks to fail fast with clear error messages rather than allowing division by zero at runtime.

```diff
+            if self.config.target_duration <= 0:
+                raise ValueError("target_duration must be > 0")
+            if self.config.shots_per_scene <= 0:
+                raise ValueError("shots_per_scene must be > 0")
             avg_shot_duration = 5.0
             total_shots = self.config.target_duration / avg_shot_duration
             num_scenes = max(1, int(total_shots / self.config.shots_per_scene))
```

<details>
<summary>🤖 Prompt for AI Agents</summary>

```
In `@packages/core/ai_content_platform/vimax/agents/screenwriter.py` around lines
132 - 136, The scene-count math can raise ZeroDivisionError or produce invalid
results when self.config.target_duration or self.config.shots_per_scene are <=
0; add explicit validation before using them (e.g., in the method that computes
num_scenes or at config load) to check that self.config.target_duration > 0 and
self.config.shots_per_scene > 0 and raise a clear ValueError (including the
offending field name and value) if not; then proceed to compute total_shots =
self.config.target_duration / avg_shot_duration and num_scenes = max(1,
int(total_shots / self.config.shots_per_scene)) as before.
```

</details>

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