inventory/inventory-server/db/metrics-schema.sql

-- Disable foreign key checks
SET FOREIGN_KEY_CHECKS = 0;

-- Temporary tables for batch metrics processing
CREATE TABLE IF NOT EXISTS temp_sales_metrics (
    product_id BIGINT NOT NULL,
    daily_sales_avg DECIMAL(10,3),
    weekly_sales_avg DECIMAL(10,3),
    monthly_sales_avg DECIMAL(10,3),
    total_revenue DECIMAL(10,3),
    avg_margin_percent DECIMAL(10,3),
    first_sale_date DATE,
    last_sale_date DATE,
    PRIMARY KEY (product_id)
);

CREATE TABLE IF NOT EXISTS temp_purchase_metrics (
    product_id BIGINT NOT NULL,
    avg_lead_time_days INT,
    last_purchase_date DATE,
    last_received_date DATE,
    PRIMARY KEY (product_id)
);

-- New table for product metrics
CREATE TABLE IF NOT EXISTS product_metrics (
    product_id BIGINT NOT NULL,
    last_calculated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    -- Sales velocity metrics
    daily_sales_avg DECIMAL(10,3),
    weekly_sales_avg DECIMAL(10,3),
    monthly_sales_avg DECIMAL(10,3),
    avg_quantity_per_order DECIMAL(10,3),
    number_of_orders INT,
    first_sale_date DATE,
    last_sale_date DATE,
    -- Stock metrics
    days_of_inventory INT,
    weeks_of_inventory INT,
    reorder_point INT,
    safety_stock INT,
    -- Financial metrics
    avg_margin_percent DECIMAL(10,3),
    total_revenue DECIMAL(10,3),
    inventory_value DECIMAL(10,3),
    -- Purchase metrics
    avg_lead_time_days INT,
    last_purchase_date DATE,
    last_received_date DATE,
    -- Classification
    abc_class CHAR(1),
    stock_status VARCHAR(20),
    PRIMARY KEY (product_id),
    FOREIGN KEY (product_id) REFERENCES products(product_id) ON DELETE CASCADE,
    INDEX idx_metrics_revenue (total_revenue)
);

-- New table for time-based aggregates
CREATE TABLE IF NOT EXISTS product_time_aggregates (
    product_id BIGINT NOT NULL,
    year INT NOT NULL,
    month INT NOT NULL,
    -- Sales metrics
    total_quantity_sold INT DEFAULT 0,
    total_revenue DECIMAL(10,3) DEFAULT 0,
    total_cost DECIMAL(10,3) DEFAULT 0,
    order_count INT DEFAULT 0,
    -- Stock changes
    stock_received INT DEFAULT 0,
    stock_ordered INT DEFAULT 0,
    -- Calculated fields
    avg_price DECIMAL(10,3),
    profit_margin DECIMAL(10,3),
    PRIMARY KEY (product_id, year, month),
    FOREIGN KEY (product_id) REFERENCES products(product_id) ON DELETE CASCADE,
    INDEX idx_date (year, month)
);

-- New table for vendor performance
CREATE TABLE IF NOT EXISTS vendor_metrics (
    vendor VARCHAR(100) NOT NULL,
    last_calculated_at TIMESTAMP NOT NULL,
    avg_lead_time_days DECIMAL(10,3),
    on_time_delivery_rate DECIMAL(5,2),
    order_fill_rate DECIMAL(5,2),
    total_orders INT,
    total_late_orders INT,
    PRIMARY KEY (vendor)
);

-- Re-enable foreign key checks
SET FOREIGN_KEY_CHECKS = 1;

-- Create view for inventory health (after all tables are created)
CREATE OR REPLACE VIEW inventory_health AS
WITH product_thresholds AS (
    SELECT 
        p.product_id,
        COALESCE(
            -- Try category+vendor specific
            (SELECT critical_days FROM stock_thresholds st 
            JOIN product_categories pc ON st.category_id = pc.category_id
            WHERE pc.product_id = p.product_id 
            AND st.vendor = p.vendor LIMIT 1),
            -- Try category specific
            (SELECT critical_days FROM stock_thresholds st 
            JOIN product_categories pc ON st.category_id = pc.category_id
            WHERE pc.product_id = p.product_id 
            AND st.vendor IS NULL LIMIT 1),
            -- Try vendor specific
            (SELECT critical_days FROM stock_thresholds st 
            WHERE st.category_id IS NULL 
            AND st.vendor = p.vendor LIMIT 1),
            -- Fall back to default
            (SELECT critical_days FROM stock_thresholds st 
            WHERE st.category_id IS NULL 
            AND st.vendor IS NULL LIMIT 1),
            7
        ) as critical_days,
        COALESCE(
            -- Try category+vendor specific
            (SELECT reorder_days FROM stock_thresholds st 
            JOIN product_categories pc ON st.category_id = pc.category_id
            WHERE pc.product_id = p.product_id 
            AND st.vendor = p.vendor LIMIT 1),
            -- Try category specific
            (SELECT reorder_days FROM stock_thresholds st 
            JOIN product_categories pc ON st.category_id = pc.category_id
            WHERE pc.product_id = p.product_id 
            AND st.vendor IS NULL LIMIT 1),
            -- Try vendor specific
            (SELECT reorder_days FROM stock_thresholds st 
            WHERE st.category_id IS NULL 
            AND st.vendor = p.vendor LIMIT 1),
            -- Fall back to default
            (SELECT reorder_days FROM stock_thresholds st 
            WHERE st.category_id IS NULL 
            AND st.vendor IS NULL LIMIT 1),
            14
        ) as reorder_days,
        COALESCE(
            -- Try category+vendor specific
            (SELECT overstock_days FROM stock_thresholds st 
            JOIN product_categories pc ON st.category_id = pc.category_id
            WHERE pc.product_id = p.product_id 
            AND st.vendor = p.vendor LIMIT 1),
            -- Try category specific
            (SELECT overstock_days FROM stock_thresholds st 
            JOIN product_categories pc ON st.category_id = pc.category_id
            WHERE pc.product_id = p.product_id 
            AND st.vendor IS NULL LIMIT 1),
            -- Try vendor specific
            (SELECT overstock_days FROM stock_thresholds st 
            WHERE st.category_id IS NULL 
            AND st.vendor = p.vendor LIMIT 1),
            -- Fall back to default
            (SELECT overstock_days FROM stock_thresholds st 
            WHERE st.category_id IS NULL 
            AND st.vendor IS NULL LIMIT 1),
            90
        ) as overstock_days
    FROM products p
)
SELECT 
    p.product_id,
    p.SKU,
    p.title,
    p.stock_quantity,
    COALESCE(pm.daily_sales_avg, 0) as daily_sales_avg,
    COALESCE(pm.days_of_inventory, 0) as days_of_inventory,
    COALESCE(pm.reorder_point, 0) as reorder_point,
    COALESCE(pm.safety_stock, 0) as safety_stock,
    CASE 
        WHEN pm.daily_sales_avg = 0 THEN 'New'
        WHEN p.stock_quantity <= CEIL(pm.daily_sales_avg * pt.critical_days) THEN 'Critical'
        WHEN p.stock_quantity <= CEIL(pm.daily_sales_avg * pt.reorder_days) THEN 'Reorder'
        WHEN p.stock_quantity > (pm.daily_sales_avg * pt.overstock_days) THEN 'Overstocked'
        ELSE 'Healthy'
    END as stock_status
FROM 
    products p
LEFT JOIN 
    product_metrics pm ON p.product_id = pm.product_id
LEFT JOIN
    product_thresholds pt ON p.product_id = pt.product_id
WHERE 
    p.managing_stock = true;

-- Create view for sales trends analysis
CREATE OR REPLACE VIEW product_sales_trends AS
SELECT 
    p.product_id,
    p.SKU,
    p.title,
    COALESCE(SUM(o.quantity), 0) as total_sold,
    COALESCE(AVG(o.quantity), 0) as avg_quantity_per_order,
    COALESCE(COUNT(DISTINCT o.order_number), 0) as number_of_orders,
    MIN(o.date) as first_sale_date,
    MAX(o.date) as last_sale_date
FROM 
    products p
LEFT JOIN 
    orders o ON p.product_id = o.product_id
WHERE 
    o.canceled = false
GROUP BY 
    p.product_id, p.SKU, p.title;