CREATE TABLE IF NOT EXISTS source_connections (
    id VARCHAR(36) PRIMARY KEY,
    source_type VARCHAR(20) NOT NULL
        CHECK (source_type IN ('pp', 'alist', 'dingtalk')),
    name VARCHAR(255) NOT NULL,
    base_url TEXT NOT NULL DEFAULT '',
    secret_ref VARCHAR(255) NOT NULL DEFAULT '',
    enabled BOOLEAN NOT NULL DEFAULT FALSE,
    schedule JSONB NOT NULL DEFAULT '{}'::jsonb
        CHECK (jsonb_typeof(schedule) = 'object'),
    last_health JSONB NOT NULL DEFAULT '{}'::jsonb
        CHECK (jsonb_typeof(last_health) = 'object'),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (name)
);

CREATE TABLE IF NOT EXISTS source_items (
    id VARCHAR(36) PRIMARY KEY,
    source_connection_id VARCHAR(36) NOT NULL
        REFERENCES source_connections(id) ON DELETE RESTRICT,
    stable_external_id TEXT NOT NULL,
    canonical_uri_hash CHAR(64) NOT NULL
        CHECK (canonical_uri_hash ~ '^[0-9a-f]{64}$'),
    parent_external_id TEXT NOT NULL DEFAULT '',
    normalized_path TEXT NOT NULL DEFAULT '',
    title TEXT NOT NULL,
    item_type VARCHAR(20) NOT NULL
        CHECK (item_type IN ('document', 'file', 'link', 'video')),
    size_bytes BIGINT CHECK (size_bytes IS NULL OR size_bytes >= 0),
    mime TEXT NOT NULL DEFAULT '',
    revision TEXT NOT NULL DEFAULT '',
    updated_at_source TIMESTAMPTZ,
    visibility VARCHAR(20) NOT NULL DEFAULT 'internal'
        CHECK (visibility IN ('internal', 'external')),
    visibility_origin VARCHAR(30) NOT NULL DEFAULT 'manual'
        CHECK (visibility_origin IN ('pp_public_tag', 'configured_scope', 'manual')),
    last_seen_scan_id VARCHAR(36) NOT NULL DEFAULT '',
    source_change VARCHAR(20) NOT NULL DEFAULT 'unchanged'
        CHECK (source_change IN ('unchanged', 'added', 'updated', 'deleted', 'unavailable')),
    absence_streak INTEGER NOT NULL DEFAULT 0 CHECK (absence_streak >= 0),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (source_connection_id, stable_external_id)
);

CREATE TABLE IF NOT EXISTS content_objects (
    id VARCHAR(36) PRIMARY KEY,
    sha256 CHAR(64) NOT NULL
        CHECK (sha256 ~ '^[0-9a-f]{64}$'),
    size_bytes BIGINT NOT NULL CHECK (size_bytes >= 0),
    mime TEXT NOT NULL DEFAULT '',
    validated_format VARCHAR(50) NOT NULL DEFAULT '',
    local_spool_ref TEXT NOT NULL DEFAULT '',
    content_state VARCHAR(20) NOT NULL DEFAULT 'unknown'
        CHECK (content_state IN ('unknown', 'downloading', 'verified', 'invalid', 'over_limit', 'failed')),
    first_discovered_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    last_discovered_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (sha256)
);

CREATE TABLE IF NOT EXISTS source_item_versions (
    id VARCHAR(36) PRIMARY KEY,
    source_item_id VARCHAR(36) NOT NULL
        REFERENCES source_items(id) ON DELETE RESTRICT,
    revision TEXT NOT NULL,
    content_object_id VARCHAR(36)
        REFERENCES content_objects(id) ON DELETE RESTRICT,
    content_state VARCHAR(20) NOT NULL DEFAULT 'unknown'
        CHECK (content_state IN ('unknown', 'downloading', 'verified', 'invalid', 'over_limit', 'failed')),
    download_error TEXT NOT NULL DEFAULT '',
    raw_record_summary JSONB NOT NULL DEFAULT '{}'::jsonb
        CHECK (jsonb_typeof(raw_record_summary) = 'object'),
    source_updated_at TIMESTAMPTZ,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (source_item_id, revision)
);

CREATE TABLE IF NOT EXISTS test_publications (
    id VARCHAR(36) PRIMARY KEY,
    source_item_version_id VARCHAR(36) NOT NULL
        REFERENCES source_item_versions(id) ON DELETE RESTRICT,
    test_kb_id VARCHAR(255) NOT NULL,
    knowledge_id VARCHAR(255) NOT NULL DEFAULT '',
    ingest_state VARCHAR(20) NOT NULL DEFAULT 'pending'
        CHECK (ingest_state IN ('pending', 'uploading', 'uploaded', 'failed')),
    processing_state VARCHAR(20) NOT NULL DEFAULT 'pending'
        CHECK (processing_state IN ('pending', 'processing', 'finalizing', 'completed', 'failed', 'stalled')),
    retrieval_state VARCHAR(20) NOT NULL DEFAULT 'unpublished'
        CHECK (retrieval_state IN ('unpublished', 'enabled', 'disabling', 'disabled', 'enabling', 'failed')),
    parser_generation VARCHAR(255) NOT NULL DEFAULT '',
    index_generation VARCHAR(255) NOT NULL DEFAULT '',
    last_error TEXT NOT NULL DEFAULT '',
    retry_count INTEGER NOT NULL DEFAULT 0 CHECK (retry_count >= 0),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (source_item_version_id, test_kb_id)
);

CREATE INDEX IF NOT EXISTS idx_source_items_change
    ON source_items (source_connection_id, source_change, updated_at DESC);

CREATE INDEX IF NOT EXISTS idx_source_items_visibility
    ON source_items (visibility, updated_at DESC);

CREATE INDEX IF NOT EXISTS idx_source_item_versions_content
    ON source_item_versions (content_object_id)
    WHERE content_object_id IS NOT NULL;

CREATE INDEX IF NOT EXISTS idx_test_publications_state
    ON test_publications (processing_state, retrieval_state, updated_at DESC);