-- Migration script to add referral points system to existing database
-- Run this script on your existing database to add referral points functionality
-- Date: 2025-12-28

SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
START TRANSACTION;
SET time_zone = "+00:00";

-- Add referral_points column to buyers table
ALTER TABLE `buyers`
  ADD COLUMN `referral_points` decimal(10,2) NOT NULL DEFAULT 0.00 AFTER `email`;

-- Add points_used column to pending_orders table
ALTER TABLE `pending_orders`
  ADD COLUMN `points_used` decimal(10,2) NOT NULL DEFAULT 0.00 AFTER `price_currency`;

-- Add points_used and price_amount columns to sales table
ALTER TABLE `sales`
  ADD COLUMN `price_amount` decimal(10,2) DEFAULT NULL AFTER `payment_id`,
  ADD COLUMN `price_currency` varchar(10) NOT NULL DEFAULT 'chf' AFTER `price_amount`,
  ADD COLUMN `points_used` decimal(10,2) NOT NULL DEFAULT 0.00 AFTER `price_currency`;

-- Create referral_point_transactions table
CREATE TABLE `referral_point_transactions` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `buyer_id` int(11) NOT NULL,
  `points` decimal(10,2) NOT NULL,
  `type` enum('earned','spent') NOT NULL,
  `sale_id` int(11) DEFAULT NULL,
  `pending_order_id` int(11) DEFAULT NULL,
  `description` text DEFAULT NULL,
  `created_at` datetime NOT NULL DEFAULT current_timestamp(),
  PRIMARY KEY (`id`),
  KEY `buyer_id` (`buyer_id`),
  KEY `sale_id` (`sale_id`),
  KEY `pending_order_id` (`pending_order_id`),
  CONSTRAINT `referral_point_transactions_ibfk_1` FOREIGN KEY (`buyer_id`) REFERENCES `buyers` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT `referral_point_transactions_ibfk_2` FOREIGN KEY (`sale_id`) REFERENCES `sales` (`id`) ON DELETE SET NULL ON UPDATE CASCADE,
  CONSTRAINT `referral_point_transactions_ibfk_3` FOREIGN KEY (`pending_order_id`) REFERENCES `pending_orders` (`id`) ON DELETE SET NULL ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;

-- Create referral_settings table
CREATE TABLE `referral_settings` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `setting_key` varchar(100) NOT NULL,
  `setting_value` varchar(255) NOT NULL,
  `description` text DEFAULT NULL,
  `updated_at` datetime NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
  PRIMARY KEY (`id`),
  UNIQUE KEY `setting_key` (`setting_key`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;

-- Insert default referral settings
INSERT INTO `referral_settings` (`setting_key`, `setting_value`, `description`) VALUES
('points_per_chf', '10', 'Number of referral points earned per 1 CHF purchase by referred user'),
('points_to_chf', '100', 'Number of referral points required to redeem 1 CHF discount');

-- Create stored procedure to award referral points
DELIMITER $$

CREATE PROCEDURE `award_referral_points`(IN p_sale_id INT)
BEGIN
  DECLARE v_buyer_id INT;
  DECLARE v_referrer_id INT;
  DECLARE v_price_amount DECIMAL(10,2);
  DECLARE v_points_per_chf DECIMAL(10,2);
  DECLARE v_points_earned DECIMAL(10,2);
  DECLARE v_drop_id INT;
  DECLARE v_size INT;
  DECLARE v_ppu DECIMAL(10,2);
  DECLARE v_currency VARCHAR(10);
  
  -- Get sale details
  SELECT buyer_id, drop_id, size, COALESCE(price_amount, 0), price_currency
  INTO v_buyer_id, v_drop_id, v_size, v_price_amount, v_currency
  FROM sales
  WHERE id = p_sale_id;
  
  -- If price_amount is not set, calculate it from drop's ppu
  IF v_price_amount = 0 OR v_price_amount IS NULL THEN
    SELECT ppu INTO v_ppu FROM drops WHERE id = v_drop_id;
    SET v_price_amount = v_ppu * v_size;
  END IF;
  
  -- Get the referrer for this buyer (if any)
  SELECT referrer INTO v_referrer_id
  FROM referrals
  WHERE referree = v_buyer_id
  LIMIT 1;
  
  -- If there's a referrer, award points
  IF v_referrer_id IS NOT NULL THEN
    -- Get points_per_chf setting
    SELECT CAST(setting_value AS DECIMAL(10,2)) INTO v_points_per_chf
    FROM referral_settings
    WHERE setting_key = 'points_per_chf'
    LIMIT 1;
    
    -- Default to 10 if setting not found
    IF v_points_per_chf IS NULL THEN
      SET v_points_per_chf = 10;
    END IF;
    
    -- Calculate points earned (based on actual purchase amount in CHF)
    SET v_points_earned = v_price_amount * v_points_per_chf;
    
    -- Update referrer's points balance
    UPDATE buyers
    SET referral_points = referral_points + v_points_earned
    WHERE id = v_referrer_id;
    
    -- Record the transaction
    INSERT INTO referral_point_transactions (
      buyer_id,
      points,
      type,
      sale_id,
      description
    ) VALUES (
      v_referrer_id,
      v_points_earned,
      'earned',
      p_sale_id,
      CONCAT('Points earned from referral purchase (Sale #', p_sale_id, ', Amount: ', v_price_amount, ' ', v_currency, ')')
    );
  END IF;
END$$

-- Create stored procedure to spend referral points
CREATE PROCEDURE `spend_referral_points`(
  IN p_buyer_id INT,
  IN p_points_to_spend DECIMAL(10,2),
  IN p_pending_order_id INT,
  IN p_sale_id INT,
  OUT p_success INT
)
BEGIN
  DECLARE v_current_points DECIMAL(10,2);
  DECLARE v_new_balance DECIMAL(10,2);
  
  -- Get current points balance
  SELECT referral_points INTO v_current_points
  FROM buyers
  WHERE id = p_buyer_id;
  
  -- Check if buyer has enough points
  IF v_current_points IS NULL OR v_current_points < p_points_to_spend THEN
    SET p_success = 0;
  ELSE
    -- Deduct points
    SET v_new_balance = v_current_points - p_points_to_spend;
    
    UPDATE buyers
    SET referral_points = v_new_balance
    WHERE id = p_buyer_id;
    
    -- Record the transaction
    INSERT INTO referral_point_transactions (
      buyer_id,
      points,
      type,
      sale_id,
      pending_order_id,
      description
    ) VALUES (
      p_buyer_id,
      p_points_to_spend,
      'spent',
      p_sale_id,
      p_pending_order_id,
      CONCAT('Points spent for purchase', 
        IF(p_sale_id IS NOT NULL, CONCAT(' (Sale #', p_sale_id, ')'), ''),
        IF(p_pending_order_id IS NOT NULL, CONCAT(' (Pending Order #', p_pending_order_id, ')'), '')
      )
    );
    
    SET p_success = 1;
  END IF;
END$$

DELIMITER ;

COMMIT;

