feat: Incomplete Core System with Missing Essential Game Functions

[KevinMB0220]

Issue: Incomplete Core System with Missing Essential Game Functions

Description:

The core system has several critical functions that are completely empty or unimplemented, preventing essential game mechanics like item spawning, marketplace integration, and tournament management from working properly.

Problems Identified:

1. Empty Marketplace Functions: move_to_market, add_to_market, and purchase_item are completely empty
2. Missing Tournament System: create_tournament and join_tournament are unimplemented
3. No Credit System: purchase_credits function is empty
4. Incomplete Item Spawning: While spawn_items works, the related market functions don't
5. Missing Admin Functions: Several admin-only functions are incomplete

Code Issues Found:

// In CoreActions - Line 109: Empty implementation
fn move_to_market(ref self: ContractState, item_ids: Array<u256>) {}

// In CoreActions - Line 110: Empty implementation  
fn add_to_market(ref self: ContractState, item_ids: Array<u256>) {}

// In CoreActions - Line 112: Empty implementation
fn purchase_item(ref self: ContractState, item_id: u256, quantity: u256) {}

// In CoreActions - Line 113: Empty implementation
fn create_tournament(ref self: ContractState) {}

// In CoreActions - Line 114: Empty implementation
fn join_tournament(ref self: ContractState) {}

// In CoreActions - Line 115: Empty implementation
fn purchase_credits(ref self: ContractState) {}

Specific Problems:

1. Broken Economy: Players can't buy/sell items because marketplace functions are empty
2. No Progression: Credit system doesn't work, preventing player progression
3. Missing Social Features: Tournament system is completely unimplemented
4. Incomplete Admin Tools: Admins can't manage the game properly
5. Broken Item Flow: Items can be spawned but can't be moved to market or purchased

Impact:

• High Priority: Game economy is completely broken
• No player progression through credits
• Missing core social features (tournaments)
• Poor admin experience due to incomplete tools
• Items can't flow from spawning to players

Recommended Solutions:

1. Implement Marketplace Functions:

   fn move_to_market(ref self: ContractState, item_ids: Array<u256>) {
       let caller = get_caller_address();
       let mut world = self.world_default();
       let contract: Contract = world.read_model(COA_CONTRACTS);
       
       // Validate caller owns items
       // Transfer items to marketplace contract
       // Update item availability status
       // Emit marketplace events
   }

2. Complete Credit System:

   fn purchase_credits(ref self: ContractState) {
       let caller = get_caller_address();
       let mut world = self.world_default();
       let contract: Contract = world.read_model(COA_CONTRACTS);
       
       // Handle payment token transfer
       // Mint credits to player
       // Update player balance
       // Emit purchase event
   }

3. Implement Tournament System:

   fn create_tournament(ref self: ContractState) {
       let caller = get_caller_address();
       let mut world = self.world_default();
       
       // Validate admin permissions
       // Create tournament model
       // Set up tournament parameters
       // Initialize tournament state
   }

4. Complete Item Purchase Logic:

   fn purchase_item(ref self: ContractState, item_id: u256, quantity: u256) {
       let caller = get_caller_address();
       let mut world = self.world_default();
       
       // Validate item availability
       // Check player has enough credits
       // Transfer item ownership
       // Update player inventory
       // Emit purchase event
   }

5. Add Admin Validation:

   fn _validate_admin(self: @ContractState) {
       let caller = get_caller_address();
       let world = self.world_default();
       let contract: Contract = world.read_model(COA_CONTRACTS);
       assert(caller == contract.admin, 'Only admin can perform this action');
   }

Files Affected:

• src/systems/core.cairo - Main core system implementation
• src/models/core.cairo - Core models and data structures
• src/interfaces/core.cairo - Core interface definitions