import { Migration } from '@mikro-orm/migrations';

export class Migration20260404083020 extends Migration {

    override async up(): Promise<void> {
        //recalc_invoice_totals
        this.addSql(`
    CREATE OR REPLACE FUNCTION recalc_invoice_totals()
    RETURNS TRIGGER AS $$
    DECLARE
        v_invoice_id char(26);
        v_subtotal int;
        v_discount int;
        v_tax int;
        v_total int;
        v_paid int;
        v_enable_tax boolean;
    BEGIN

        v_invoice_id := COALESCE(NEW.invoice_id, OLD.invoice_id);

        SELECT
            COALESCE(SUM(sub_total),0),
            COALESCE(SUM(discount),0)
        INTO
            v_subtotal,
            v_discount
        FROM invoice_items
        WHERE invoice_id = v_invoice_id
        AND deleted_at IS NULL;

        SELECT enable_tax
        INTO v_enable_tax
        FROM invoices
        WHERE id = v_invoice_id;

        IF v_enable_tax THEN
            v_tax := (v_subtotal - v_discount) * 0.10;
        ELSE
            v_tax := 0;
        END IF;

        v_total := (v_subtotal - v_discount) + v_tax;

        SELECT COALESCE(SUM(amount),0)
        INTO v_paid
        FROM payments
        WHERE invoice_id = v_invoice_id
        AND status = 'paid'
        AND deleted_at IS NULL;

        UPDATE invoices
        SET
            sub_total = v_subtotal,
            discount = v_discount,
            tax_amount = v_tax,
            total = v_total,
            paid_amount = v_paid,
            balance = v_total - v_paid
        WHERE id = v_invoice_id;

        RETURN NULL;
    END;
    $$ LANGUAGE plpgsql;
    `);

        // trigger
        this.addSql(`
    CREATE TRIGGER trg_invoice_items_recalc
    AFTER INSERT OR UPDATE OR DELETE
    ON invoice_items
    FOR EACH ROW
    EXECUTE FUNCTION recalc_invoice_totals();
    `);

        // recalc_invoice_payments
        this.addSql(`
    CREATE OR REPLACE FUNCTION recalc_invoice_payments()
    RETURNS TRIGGER AS $$
    DECLARE
        v_invoice_id char(26);
        v_paid int;
        v_total int;
    BEGIN

        v_invoice_id := COALESCE(NEW.invoice_id, OLD.invoice_id);

        SELECT COALESCE(SUM(amount),0)
        INTO v_paid
        FROM payments
        WHERE invoice_id = v_invoice_id
        AND status = 'paid'
        AND deleted_at IS NULL;

        SELECT total
        INTO v_total
        FROM invoices
        WHERE id = v_invoice_id;

        UPDATE invoices
        SET
            paid_amount = v_paid,
            balance = v_total - v_paid
        WHERE id = v_invoice_id;

        RETURN NULL;
    END;
    $$ LANGUAGE plpgsql;
    `);

        // trigger
        this.addSql(`
    CREATE TRIGGER trg_payments_recalc
    AFTER INSERT OR UPDATE OR DELETE
    ON payments
    FOR EACH ROW
    EXECUTE FUNCTION recalc_invoice_payments();
    `);

        this.addSql(`CREATE SEQUENCE invoice_number_seq START 1;`);

        this.addSql(`
        ALTER TABLE invoices 
        ALTER COLUMN invoice_number 
        SET DEFAULT nextval('invoice_number_seq');
        `);

    }

    override async down(): Promise<void> {

        this.addSql(`DROP TRIGGER IF EXISTS trg_invoice_items_recalc ON invoice_items;`);
        this.addSql(`DROP TRIGGER IF EXISTS trg_payments_recalc ON payments;`);

        this.addSql(`DROP FUNCTION IF EXISTS recalc_invoice_totals;`);
        this.addSql(`DROP FUNCTION IF EXISTS recalc_invoice_payments;`);


        // remove default from invoice_number
        this.addSql(`
        ALTER TABLE invoices 
        ALTER COLUMN invoice_number 
        DROP DEFAULT;
    `);

        // drop sequence
        this.addSql(`DROP SEQUENCE IF EXISTS invoice_number_seq;`);

    }

}