gbserver/prompts/dev/model.md

Create a Rust data model for database storage with optimal size and performance characteristics. Follow these specifications:

REQUIREMENTS:

1. Use appropriate integer types (i32, i16, i8, etc.) based on expected value ranges
2. Use Option<T> for nullable fields to avoid memory overhead
3. Use Vec<u8> for binary data instead of strings when appropriate
4. Prefer enum representations as integers rather than strings
5. Use chrono::DateTime<Utc> for timestamps
6. Use uuid::Uuid for unique identifiers
7. Implement necessary traits: Debug, Clone, Serialize, Deserialize, FromRow
8. Include validation where appropriate
9. Consider database index strategy in field design

CONTEXT:

• Database: PostgreSQL/SQLx compatible
• Serialization: Serde for JSON
• ORM: SQLx for database operations

OUTPUT FORMAT: Provide the complete Rust struct with:

• Struct definition with fields
• Enum definitions with integer representations
• Conversion implementations
• Basic validation if needed

EXAMPLE REFERENCE:

use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use sqlx::FromRow;
use uuid::Uuid;

#[derive(Debug, Clone, Copy, PartialEq)]
pub enum Status {
    Pending = 0,
    Active = 1,
    Inactive = 2,
}

impl Status {
    pub fn from_i16(value: i16) -> Option<Self> {
        match value {
            0 => Some(Self::Pending),
            1 => Some(Self::Active),
            2 => Some(Self::Inactive),
            _ => None,
        }
    }
}

#[derive(Debug, FromRow, Serialize, Deserialize)]
pub struct User {
    pub id: Uuid,
    pub status: i16, // Using i16 for enum storage
    pub email: String,
    pub age: Option<i16>, // Nullable small integer
    pub metadata: Vec<u8>, // Binary data for flexibility
    pub created_at: DateTime<Utc>,
}

Generate a similar model for: [YOUR DOMAIN HERE]

## Specialized Variants

### For High-Performance Applications

Add these additional requirements:

• Use #[repr(u8)] for enums to ensure minimal size
• Consider Box<str> instead of String for reduced heap overhead
• Use arrayvec::ArrayString for fixed-size short strings
• Implement PartialEq and Eq for hash-based operations
• Include #[derive(Default)] where appropriate

### For Embedded/Memory-Constrained Systems

Add these constraints:

• Prefer i16 over i32 where possible
• Use u32 instead of Uuid if sequential IDs are acceptable
• Consider bitflags for multiple boolean flags in single byte
• Use smol_str::SmolStr for string optimization
• Avoid Vec in favor of arrays with capacity limits

### For Time-Series Data

Add time-series specific optimizations:

• Use i64 for timestamps as nanoseconds since epoch
• Use f32 instead of f64 for measurements where precision allows
• Consider ordered_float::OrderedFloat for floating-point comparisons
• Use #[serde(with = "chrono::serde::ts_seconds")] for compact serialization