-- PostgreSQL-specific schema with BIGINT UNIX timestamps
-- Main content table (current versions only)
CREATE TABLE content (
    id TEXT NOT NULL,
    site_id TEXT NOT NULL,
    value TEXT NOT NULL,
    type TEXT NOT NULL,
    created_at BIGINT DEFAULT EXTRACT(EPOCH FROM NOW()) NOT NULL,
    updated_at BIGINT DEFAULT EXTRACT(EPOCH FROM NOW()) NOT NULL,
    last_edited_by TEXT DEFAULT 'system' NOT NULL,
    PRIMARY KEY (id, site_id)
);

-- Version history table for rollback functionality
CREATE TABLE content_versions (
    version_id SERIAL PRIMARY KEY,
    content_id TEXT NOT NULL,
    site_id TEXT NOT NULL,
    value TEXT NOT NULL,
    type TEXT NOT NULL,
    created_at BIGINT DEFAULT EXTRACT(EPOCH FROM NOW()) NOT NULL,
    created_by TEXT DEFAULT 'system' NOT NULL
);

-- Indexes for performance
CREATE INDEX IF NOT EXISTS idx_content_site_id ON content(site_id);
CREATE INDEX IF NOT EXISTS idx_content_updated_at ON content(updated_at);
CREATE INDEX IF NOT EXISTS idx_content_versions_lookup ON content_versions(content_id, site_id, created_at DESC);

-- Function and trigger to automatically update updated_at timestamp
CREATE OR REPLACE FUNCTION update_updated_at_column()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = EXTRACT(EPOCH FROM NOW());
    RETURN NEW;
END;
$$ language 'plpgsql';

CREATE TRIGGER update_content_updated_at
    BEFORE UPDATE ON content
    FOR EACH ROW
    EXECUTE FUNCTION update_updated_at_column();