CREATE TYPE item_tier AS ENUM ('fixed', 'variable', 'one_off');

ALTER TABLE budget_items ADD COLUMN item_tier item_tier NOT NULL DEFAULT 'fixed';

CREATE TABLE IF NOT EXISTS templates (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    name TEXT NOT NULL DEFAULT 'My Template',
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE UNIQUE INDEX idx_templates_user_id ON templates (user_id);

CREATE TABLE IF NOT EXISTS template_items (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    template_id UUID NOT NULL REFERENCES templates(id) ON DELETE CASCADE,
    category_id UUID NOT NULL REFERENCES categories(id) ON DELETE RESTRICT,
    item_tier item_tier NOT NULL,
    budgeted_amount NUMERIC(12, 2),
    sort_order INT NOT NULL DEFAULT 0,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    CONSTRAINT chk_template_items_no_one_off CHECK (item_tier IN ('fixed', 'variable'))
);

CREATE INDEX idx_template_items_template_id ON template_items (template_id);