-- Migration 177: Supplier invoice reminders
-- Created: 2026-04-13

CREATE TABLE IF NOT EXISTS supplier_invoice_reminders (
    id BIGSERIAL PRIMARY KEY,
    supplier_invoice_id INTEGER NOT NULL REFERENCES supplier_invoices(id) ON DELETE CASCADE,
    reminder_type VARCHAR(30) NOT NULL,
    remind_at TIMESTAMP NOT NULL,
    status VARCHAR(20) NOT NULL DEFAULT 'pending',
    sent_at TIMESTAMP,
    channel VARCHAR(20) NOT NULL DEFAULT 'in_app',
    payload_json JSONB NOT NULL DEFAULT '{}'::jsonb,
    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
);

DO $$
BEGIN
    IF NOT EXISTS (
        SELECT 1
        FROM pg_constraint
        WHERE conname = 'chk_supplier_invoice_reminders_type'
    ) THEN
        ALTER TABLE supplier_invoice_reminders
        ADD CONSTRAINT chk_supplier_invoice_reminders_type
        CHECK (reminder_type IN ('due_soon', 'overdue', 'manual'));
    END IF;
END $$;

DO $$
BEGIN
    IF NOT EXISTS (
        SELECT 1
        FROM pg_constraint
        WHERE conname = 'chk_supplier_invoice_reminders_status'
    ) THEN
        ALTER TABLE supplier_invoice_reminders
        ADD CONSTRAINT chk_supplier_invoice_reminders_status
        CHECK (status IN ('pending', 'sent', 'cancelled', 'failed'));
    END IF;
END $$;

DO $$
BEGIN
    IF NOT EXISTS (
        SELECT 1
        FROM pg_constraint
        WHERE conname = 'chk_supplier_invoice_reminders_channel'
    ) THEN
        ALTER TABLE supplier_invoice_reminders
        ADD CONSTRAINT chk_supplier_invoice_reminders_channel
        CHECK (channel IN ('in_app', 'email'));
    END IF;
END $$;

CREATE INDEX IF NOT EXISTS idx_supplier_invoice_reminders_supplier_invoice_id
ON supplier_invoice_reminders(supplier_invoice_id);

CREATE INDEX IF NOT EXISTS idx_supplier_invoice_reminders_remind_at
ON supplier_invoice_reminders(remind_at);

CREATE INDEX IF NOT EXISTS idx_supplier_invoice_reminders_status
ON supplier_invoice_reminders(status);

CREATE INDEX IF NOT EXISTS idx_supplier_invoice_reminders_payload_json
ON supplier_invoice_reminders USING GIN (payload_json);

CREATE OR REPLACE FUNCTION update_supplier_invoice_reminders_updated_at()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = CURRENT_TIMESTAMP;
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

DROP TRIGGER IF EXISTS trg_supplier_invoice_reminders_updated_at ON supplier_invoice_reminders;
CREATE TRIGGER trg_supplier_invoice_reminders_updated_at
    BEFORE UPDATE ON supplier_invoice_reminders
    FOR EACH ROW
    EXECUTE FUNCTION update_supplier_invoice_reminders_updated_at();

COMMENT ON TABLE supplier_invoice_reminders IS 'Scheduled reminders for supplier invoice follow-up';
COMMENT ON COLUMN supplier_invoice_reminders.reminder_type IS 'due_soon, overdue, or manual';
COMMENT ON COLUMN supplier_invoice_reminders.status IS 'pending, sent, cancelled, or failed';
COMMENT ON COLUMN supplier_invoice_reminders.channel IS 'Delivery channel: in_app or email';