CREATE EXTENSION IF NOT EXISTS vector;

CREATE TABLE documents (
    id BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    title TEXT NOT NULL,
    source TEXT,
    status TEXT NOT NULL DEFAULT 'pending'
        CHECK (status IN ('pending', 'processing', 'completed', 'failed')),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE TABLE document_chunks (
    id BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    document_id BIGINT NOT NULL REFERENCES documents(id) ON DELETE CASCADE,
    chunk_index INTEGER NOT NULL CHECK (chunk_index >= 0),
    content TEXT NOT NULL,
    embedding vector(768) NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (document_id, chunk_index)
);

CREATE INDEX document_chunks_document_id_idx
    ON document_chunks (document_id);