-- Create expenses table for tracking business expenses
CREATE TABLE IF NOT EXISTS expenses (
    id INT AUTO_INCREMENT PRIMARY KEY,
    branch_id INT NOT NULL,
    category VARCHAR(50) NOT NULL COMMENT 'COGS, Salaries, Rent, Utilities, Marketing, Other',
    description TEXT,
    amount DECIMAL(12,2) NOT NULL,
    expense_date DATE NOT NULL,
    created_by INT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    FOREIGN KEY (branch_id) REFERENCES branches(id),
    FOREIGN KEY (created_by) REFERENCES users(id),
    INDEX idx_expense_date (expense_date),
    INDEX idx_category (category),
    INDEX idx_branch (branch_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

-- Add cost_price column to products table for COGS calculation
ALTER TABLE products 
ADD COLUMN IF NOT EXISTS cost_price DECIMAL(10,2) DEFAULT 0.00 COMMENT 'Purchase/Cost price for COGS calculation';