# Mathematical Expressions

RewardSystem allows you to use mathematical expressions in your config.yml file. These expressions enable you to create dynamic rewards based on player level, damage dealt, and other metrics.

## Basic Syntax

Mathematical expressions use the following format: `{math:expression}`

For example:

```yaml
give %player% diamond {math:2 + (%player_level% / 10)} 
```

## Chance Expressions

Chance expressions are created by adding a percentage sign (%) at the end of the command:

```yaml
give %player% diamond 1 {math:10 + (%player_level% * 2)}%
```

This gives a 20% chance (10 + 5\*2 = 20%) if the player's level is 5.

## Configuration Example

```yaml
zombie:
  id: zombie_reward
  type: ZOMBIE
  name: "Rotting Zombie"
  minimumDamagePercent: 5.0
  radius: 50
  cooldown: 60
  cooldownType: MINUTES
  
  allRewards:
    - "give %player% minecraft:coal 5"
    - "give %player% minecraft:diamond 1 50.0%"  # Fixed chance value
    - "give %player% minecraft:emerald 2 {math:20 + (%player_level% / 10)}%"  # Dynamic chance
    
  rewards:
    1:  # Most damage player
      - "give %player% minecraft:diamond 3"
      - "give %player% minecraft:netherite_ingot 1 {math:10 + (%player_level% / 100)}%"
    2:  # Second most damage player
      - "give %player% minecraft:iron_ingot 5"
      - "give %player% minecraft:diamond 1 25.0%"
      
  lastHitRewards:  # Last hit player
    - "give %player% minecraft:experience_bottle 5"
    - "give %player% minecraft:diamond 3 {math:%player_level% * 5}%"
```

## Available Variables

You can use the following variables in your mathematical expressions:

* `%player_level%`: Player's level
* `%personal_damage%`: Damage dealt by the player to the mob
* `%top_damage_1%`, `%top_damage_2%`, etc.: Damage values on the leaderboard
* All other values provided by PlaceholderAPI

## Supported Operations

* Addition: `+`
* Subtraction: `-`
* Multiplication: `*`
* Division: `/`
* Modulo (remainder): `%`
* Parentheses: `(expression)`

## Example Uses

1. Reward amount based on player level:

   ```yaml
   give %player% minecraft:diamond {math:1 + (%player_level% / 10)}
   ```
2. Chance based on damage dealt:

   ```yaml
   give %player% minecraft:nether_star 1 {math:(%personal_damage% / 20) + 5}%
   ```
3. Simple calculations:

   ```yaml
   give %player% minecraft:emerald {math:(%player_level% / 5) + 2}
   ```
4. Multi-step calculations with parentheses:

   ```yaml
   give %player% minecraft:gold_ingot {math:((%player_level% * 2) + 5) / 3}
   ```
5. Using server statistics:

   ```yaml
   give %player% minecraft:ender_pearl {math:(%server.online% + 1) / 2}
   ```

## Error Handling

If an expression cannot be evaluated (syntax error, variable issue, etc.), the system:

* For chance calculations: uses a default 50% chance
* For item amounts: uses a default value of 1

This ensures that commands continue to work even when mathematical expressions have issues.

## Practical Tips

* Keep expressions simple for better performance
* Test your expressions with various player levels and damage values
* Use debug mode to verify that expressions are evaluated correctly
* Consider edge cases like new players (low levels) or very high damage values