likwid/backend/migrations/20260126210000_plugin_kv_store.sql

-- Plugin Key-Value Store for WASM plugins
-- Provides persistent storage for plugin data with isolation per plugin/community

CREATE TABLE plugin_kv_store (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    
    -- Plugin identification
    plugin_name VARCHAR(255) NOT NULL,
    
    -- Optional community scope (NULL = global/instance-level)
    community_id UUID REFERENCES communities(id) ON DELETE CASCADE,
    
    -- Key-value pair
    key VARCHAR(512) NOT NULL,
    value JSONB NOT NULL DEFAULT '{}',
    
    -- Metadata
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW(),
    expires_at TIMESTAMPTZ, -- Optional TTL
    
    -- Unique constraint per plugin/community/key combination
    UNIQUE(plugin_name, community_id, key)
);

-- Index for fast lookups
CREATE INDEX idx_plugin_kv_plugin ON plugin_kv_store(plugin_name);
CREATE INDEX idx_plugin_kv_community ON plugin_kv_store(community_id);
CREATE INDEX idx_plugin_kv_lookup ON plugin_kv_store(plugin_name, community_id, key);
CREATE INDEX idx_plugin_kv_expires ON plugin_kv_store(expires_at) WHERE expires_at IS NOT NULL;

-- Plugin events table for event emission
CREATE TABLE plugin_events (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    
    -- Event source
    plugin_name VARCHAR(255) NOT NULL,
    community_id UUID REFERENCES communities(id) ON DELETE CASCADE,
    actor_user_id UUID REFERENCES users(id) ON DELETE SET NULL,
    
    -- Event data
    event_name VARCHAR(255) NOT NULL,
    payload JSONB NOT NULL DEFAULT '{}',
    
    -- Timestamps
    created_at TIMESTAMPTZ DEFAULT NOW(),
    
    -- Processing status (for async event handlers)
    processed BOOLEAN DEFAULT FALSE,
    processed_at TIMESTAMPTZ
);

-- Index for event queries
CREATE INDEX idx_plugin_events_name ON plugin_events(event_name);
CREATE INDEX idx_plugin_events_plugin ON plugin_events(plugin_name);
CREATE INDEX idx_plugin_events_community ON plugin_events(community_id);
CREATE INDEX idx_plugin_events_unprocessed ON plugin_events(processed) WHERE processed = FALSE;
CREATE INDEX idx_plugin_events_created ON plugin_events(created_at DESC);

-- Function to get plugin setting
CREATE OR REPLACE FUNCTION get_plugin_setting(
    p_plugin_name VARCHAR(255),
    p_community_id UUID,
    p_key VARCHAR(255)
) RETURNS JSONB AS $$
DECLARE
    v_setting JSONB;
BEGIN
    -- First try community-specific setting
    IF p_community_id IS NOT NULL THEN
        SELECT settings->p_key INTO v_setting
        FROM community_plugins cp
        JOIN plugins p ON p.id = cp.plugin_id
        WHERE p.name = p_plugin_name AND cp.community_id = p_community_id;
        
        IF v_setting IS NOT NULL THEN
            RETURN v_setting;
        END IF;
    END IF;
    
    -- Fall back to plugin default settings
    SELECT default_settings->p_key INTO v_setting
    FROM plugins
    WHERE name = p_plugin_name;
    
    RETURN COALESCE(v_setting, 'null'::jsonb);
END;
$$ LANGUAGE plpgsql;

-- Function to set KV value
CREATE OR REPLACE FUNCTION plugin_kv_set(
    p_plugin_name VARCHAR(255),
    p_community_id UUID,
    p_key VARCHAR(512),
    p_value JSONB,
    p_ttl_seconds INTEGER DEFAULT NULL
) RETURNS BOOLEAN AS $$
DECLARE
    v_expires_at TIMESTAMPTZ;
BEGIN
    IF p_ttl_seconds IS NOT NULL THEN
        v_expires_at := NOW() + (p_ttl_seconds || ' seconds')::interval;
    END IF;
    
    INSERT INTO plugin_kv_store (plugin_name, community_id, key, value, expires_at)
    VALUES (p_plugin_name, p_community_id, p_key, p_value, v_expires_at)
    ON CONFLICT (plugin_name, community_id, key) 
    DO UPDATE SET 
        value = EXCLUDED.value,
        updated_at = NOW(),
        expires_at = EXCLUDED.expires_at;
    
    RETURN TRUE;
END;
$$ LANGUAGE plpgsql;

-- Function to get KV value
CREATE OR REPLACE FUNCTION plugin_kv_get(
    p_plugin_name VARCHAR(255),
    p_community_id UUID,
    p_key VARCHAR(512)
) RETURNS JSONB AS $$
DECLARE
    v_value JSONB;
BEGIN
    SELECT value INTO v_value
    FROM plugin_kv_store
    WHERE plugin_name = p_plugin_name 
      AND (community_id = p_community_id OR (p_community_id IS NULL AND community_id IS NULL))
      AND key = p_key
      AND (expires_at IS NULL OR expires_at > NOW());
    
    RETURN v_value;
END;
$$ LANGUAGE plpgsql;

-- Function to delete KV value
CREATE OR REPLACE FUNCTION plugin_kv_delete(
    p_plugin_name VARCHAR(255),
    p_community_id UUID,
    p_key VARCHAR(512)
) RETURNS BOOLEAN AS $$
BEGIN
    DELETE FROM plugin_kv_store
    WHERE plugin_name = p_plugin_name 
      AND (community_id = p_community_id OR (p_community_id IS NULL AND community_id IS NULL))
      AND key = p_key;
    
    RETURN FOUND;
END;
$$ LANGUAGE plpgsql;

-- Cleanup job for expired KV entries (to be run periodically)
CREATE OR REPLACE FUNCTION cleanup_expired_plugin_kv() RETURNS INTEGER AS $$
DECLARE
    deleted_count INTEGER;
BEGIN
    DELETE FROM plugin_kv_store WHERE expires_at IS NOT NULL AND expires_at < NOW();
    GET DIAGNOSTICS deleted_count = ROW_COUNT;
    RETURN deleted_count;
END;
$$ LANGUAGE plpgsql;