CREATE TABLE IF NOT EXISTS content_nodes (
    id UUID DEFAULT gen_random_uuid() PRIMARY KEY,
    node_type VARCHAR(50) NOT NULL,
    path TEXT NOT NULL,
    disk_label VARCHAR(50),
    parent_id UUID REFERENCES content_nodes(id) ON DELETE CASCADE,

    checksum VARCHAR(64),
    size BIGINT,
    modified_time TIMESTAMP,

    content_hash VARCHAR(64),
    extracted_at TIMESTAMP,
    extraction_method VARCHAR(100),

    metadata JSONB,

    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,

    UNIQUE(node_type, path, disk_label)
);

CREATE INDEX IF NOT EXISTS idx_content_nodes_type ON content_nodes(node_type);
CREATE INDEX IF NOT EXISTS idx_content_nodes_path ON content_nodes(path);
CREATE INDEX IF NOT EXISTS idx_content_nodes_parent ON content_nodes(parent_id);
CREATE INDEX IF NOT EXISTS idx_content_nodes_checksum ON content_nodes(checksum);
CREATE INDEX IF NOT EXISTS idx_content_nodes_content_hash ON content_nodes(content_hash);

CREATE TABLE IF NOT EXISTS content_edges (
    id UUID DEFAULT gen_random_uuid() PRIMARY KEY,
    source_id UUID NOT NULL REFERENCES content_nodes(id) ON DELETE CASCADE,
    target_id UUID NOT NULL REFERENCES content_nodes(id) ON DELETE CASCADE,
    edge_type VARCHAR(50) NOT NULL,

    metadata JSONB,
    confidence FLOAT,

    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,

    UNIQUE(source_id, target_id, edge_type)
);

CREATE INDEX IF NOT EXISTS idx_content_edges_source ON content_edges(source_id);
CREATE INDEX IF NOT EXISTS idx_content_edges_target ON content_edges(target_id);
CREATE INDEX IF NOT EXISTS idx_content_edges_type ON content_edges(edge_type);

CREATE TABLE IF NOT EXISTS extraction_log (
    id UUID DEFAULT gen_random_uuid() PRIMARY KEY,
    node_id UUID REFERENCES content_nodes(id) ON DELETE CASCADE,
    file_path TEXT NOT NULL,
    file_checksum VARCHAR(64),

    extraction_method VARCHAR(100),
    status VARCHAR(50),
    error_message TEXT,

    extracted_size BIGINT,
    processing_time_ms INT,

    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

CREATE INDEX IF NOT EXISTS idx_extraction_log_node ON extraction_log(node_id);
CREATE INDEX IF NOT EXISTS idx_extraction_log_file ON extraction_log(file_path);
CREATE INDEX IF NOT EXISTS idx_extraction_log_checksum ON extraction_log(file_checksum);
CREATE INDEX IF NOT EXISTS idx_extraction_log_status ON extraction_log(status);
CREATE INDEX IF NOT EXISTS idx_extraction_log_created ON extraction_log(created_at DESC);

COMMENT ON TABLE content_nodes IS 'Content graph nodes: directories, files, chunks';
COMMENT ON TABLE content_edges IS 'Content graph edges: contains, derived_from, references, duplicates';
COMMENT ON TABLE extraction_log IS 'Tracks extraction history for incremental updates';

COMMENT ON COLUMN content_nodes.node_type IS 'directory, file, chunk, embedding';
COMMENT ON COLUMN content_nodes.content_hash IS 'Hash of extracted content (not file bytes)';
COMMENT ON COLUMN content_edges.edge_type IS 'contains, derived_from, references, duplicates, similar_to';