# THEME PRESETS USAGE GUIDE

## What Changed in Your Presets

### ✅ What You Had Right
- Good preset structure with colors, fonts, layout
- Clean `apply_preset()` function
- Good preset names (modern, classic, minimal, vibrant)

### 🔧 What We Added
1. **Missing color fields:** `background`, `text`, `border`
2. **Missing layout field:** `product_card` style
3. **"default" preset:** Your platform's default theme
4. **Extra presets:** "elegant" and "nature" themes
5. **Helper functions:** `get_preset()`, `get_available_presets()`, `get_preset_preview()`
6. **Custom preset builder:** `create_custom_preset()`

---

## Usage Examples

### 1. Apply Preset to New Vendor

```python
from models.database.vendor_theme import VendorTheme
from app.core.theme_presets import apply_preset
from app.core.database import SessionLocal

# Create theme for vendor
db = SessionLocal()
vendor_id = 1

# Create and apply preset
theme = VendorTheme(vendor_id=vendor_id)
apply_preset(theme, "modern")

db.add(theme)
db.commit()
```

### 2. Change Vendor's Theme

```python
from models.database.vendor_theme import VendorTheme
from app.core.theme_presets import apply_preset

# Get existing theme
theme = db.query(VendorTheme).filter(
    VendorTheme.vendor_id == vendor_id
).first()

if theme:
    # Update to new preset
    apply_preset(theme, "classic")
else:
    # Create new theme
    theme = VendorTheme(vendor_id=vendor_id)
    apply_preset(theme, "classic")
    db.add(theme)

db.commit()
```

### 3. Get Available Presets (For UI Dropdown)

```python
from app.core.theme_presets import get_available_presets, get_preset_preview

# Get list of preset names
presets = get_available_presets()
# Returns: ['default', 'modern', 'classic', 'minimal', 'vibrant', 'elegant', 'nature']

# Get preview info for UI
previews = []
for preset_name in presets:
    preview = get_preset_preview(preset_name)
    previews.append(preview)

# Returns list of dicts with:
# {
#     "name": "modern",
#     "description": "Contemporary tech-inspired design...",
#     "primary_color": "#6366f1",
#     "secondary_color": "#8b5cf6",
#     ...
# }
```

### 4. API Endpoint to Apply Preset

```python
# In your API route
from fastapi import APIRouter, Depends
from app.core.theme_presets import apply_preset, get_available_presets

@router.put("/theme/preset")
def apply_theme_preset(
    preset_name: str,
    vendor: Vendor = Depends(require_vendor_context()),
    db: Session = Depends(get_db),
):
    """Apply a theme preset to vendor."""
    
    # Validate preset name
    if preset_name not in get_available_presets():
        raise HTTPException(
            status_code=400,
            detail=f"Invalid preset. Available: {get_available_presets()}"
        )
    
    # Get or create vendor theme
    theme = db.query(VendorTheme).filter(
        VendorTheme.vendor_id == vendor.id
    ).first()
    
    if not theme:
        theme = VendorTheme(vendor_id=vendor.id)
        db.add(theme)
    
    # Apply preset
    apply_preset(theme, preset_name)
    db.commit()
    db.refresh(theme)
    
    return {
        "message": f"Theme preset '{preset_name}' applied successfully",
        "theme": theme.to_dict()
    }
```

### 5. Get All Presets for Theme Selector

```python
@router.get("/theme/presets")
def get_theme_presets():
    """Get all available theme presets with previews."""
    from app.core.theme_presets import get_available_presets, get_preset_preview
    
    presets = []
    for preset_name in get_available_presets():
        preview = get_preset_preview(preset_name)
        presets.append(preview)
    
    return {"presets": presets}

# Returns:
# {
#   "presets": [
#     {
#       "name": "default",
#       "description": "Clean and professional...",
#       "primary_color": "#6366f1",
#       "secondary_color": "#8b5cf6",
#       "accent_color": "#ec4899",
#       "heading_font": "Inter, sans-serif",
#       "body_font": "Inter, sans-serif",
#       "layout_style": "grid"
#     },
#     ...
#   ]
# }
```

### 6. Create Custom Theme (Not from Preset)

```python
from app.core.theme_presets import create_custom_preset

# User provides custom colors
custom_preset = create_custom_preset(
    colors={
        "primary": "#ff0000",
        "secondary": "#00ff00",
        "accent": "#0000ff",
        "background": "#ffffff",
        "text": "#000000",
        "border": "#cccccc"
    },
    fonts={
        "heading": "Arial, sans-serif",
        "body": "Verdana, sans-serif"
    },
    layout={
        "style": "grid",
        "header": "fixed",
        "product_card": "modern"
    },
    name="my_custom"
)

# Apply to vendor theme
theme = VendorTheme(vendor_id=vendor_id)
theme.theme_name = "custom"
theme.colors = custom_preset["colors"]
theme.font_family_heading = custom_preset["fonts"]["heading"]
theme.font_family_body = custom_preset["fonts"]["body"]
theme.layout_style = custom_preset["layout"]["style"]
theme.header_style = custom_preset["layout"]["header"]
theme.product_card_style = custom_preset["layout"]["product_card"]
theme.is_active = True

db.add(theme)
db.commit()
```

---

## Available Presets

| Preset | Description | Primary Color | Use Case |
|--------|-------------|---------------|----------|
| `default` | Clean & professional | Indigo (#6366f1) | General purpose |
| `modern` | Tech-inspired | Indigo (#6366f1) | Tech products |
| `classic` | Traditional | Dark Blue (#1e40af) | Established brands |
| `minimal` | Ultra-clean B&W | Black (#000000) | Minimalist brands |
| `vibrant` | Bold & energetic | Orange (#f59e0b) | Creative brands |
| `elegant` | Sophisticated | Gray (#6b7280) | Luxury products |
| `nature` | Eco-friendly | Green (#059669) | Organic/eco brands |

---

## Complete Preset Structure

Each preset includes:

```python
{
    "colors": {
        "primary": "#6366f1",      # Main brand color
        "secondary": "#8b5cf6",    # Supporting color
        "accent": "#ec4899",       # Call-to-action color
        "background": "#ffffff",   # Page background
        "text": "#1f2937",        # Text color
        "border": "#e5e7eb"       # Border/divider color
    },
    "fonts": {
        "heading": "Inter, sans-serif",  # Headings (h1-h6)
        "body": "Inter, sans-serif"      # Body text
    },
    "layout": {
        "style": "grid",           # grid | list | masonry
        "header": "fixed",         # fixed | static | transparent
        "product_card": "modern"   # modern | classic | minimal
    }
}
```

---

## Integration with Admin Panel

### Theme Editor UI Flow

1. **Preset Selector**
   ```javascript
   // Fetch available presets
   fetch('/api/v1/vendor/theme/presets')
     .then(r => r.json())
     .then(data => {
       // Display preset cards with previews
       data.presets.forEach(preset => {
         showPresetCard(preset.name, preset.primary_color, preset.description)
       })
     })
   ```

2. **Apply Preset Button**
   ```javascript
   function applyPreset(presetName) {
     fetch('/api/v1/vendor/theme/preset', {
       method: 'PUT',
       headers: {'Content-Type': 'application/json'},
       body: JSON.stringify({preset_name: presetName})
     })
     .then(() => {
       alert('Theme updated!')
       location.reload()  // Refresh to show new theme
     })
   }
   ```

3. **Custom Color Picker** (After applying preset)
   ```javascript
   // User can then customize colors
   function updateColors(colors) {
     fetch('/api/v1/vendor/theme/colors', {
       method: 'PUT',
       body: JSON.stringify({colors})
     })
   }
   ```

---

## Testing Presets

```python
# Test script
from app.core.theme_presets import apply_preset, get_available_presets
from models.database.vendor_theme import VendorTheme

def test_all_presets():
    """Test applying all presets"""
    presets = get_available_presets()
    
    for preset_name in presets:
        theme = VendorTheme(vendor_id=999)  # Test vendor
        apply_preset(theme, preset_name)
        
        assert theme.theme_name == preset_name
        assert theme.colors is not None
        assert theme.font_family_heading is not None
        assert theme.is_active == True
        
        print(f"✅ {preset_name} preset OK")

test_all_presets()
```

---

## CSS Variables Generation

Your middleware already handles this via `VendorTheme.to_dict()`, which includes:

```python
"css_variables": {
    "--color-primary": "#6366f1",
    "--color-secondary": "#8b5cf6",
    "--color-accent": "#ec4899",
    "--color-background": "#ffffff",
    "--color-text": "#1f2937",
    "--color-border": "#e5e7eb",
    "--font-heading": "Inter, sans-serif",
    "--font-body": "Inter, sans-serif",
}
```

Use in templates:
```html
<style>
:root {
  {% for key, value in theme.css_variables.items() %}
  {{ key }}: {{ value }};
  {% endfor %}
}
</style>
```

---

## Next Steps

1. ✅ Copy `theme_presets.py` to `app/core/theme_presets.py`
2. ✅ Create API endpoints for applying presets
3. ✅ Build theme selector UI in admin panel
4. ✅ Test all presets work correctly
5. ✅ Add custom color picker for fine-tuning

Perfect! Your presets are now complete and production-ready! 🎨
