BEGIN;

ALTER TABLE leaudit_documents
    ADD COLUMN IF NOT EXISTS version_group_key VARCHAR(64),
    ADD COLUMN IF NOT EXISTS version_no INTEGER NOT NULL DEFAULT 1,
    ADD COLUMN IF NOT EXISTS previous_version_id BIGINT,
    ADD COLUMN IF NOT EXISTS root_version_id BIGINT,
    ADD COLUMN IF NOT EXISTS is_latest_version BOOLEAN NOT NULL DEFAULT true,
    ADD COLUMN IF NOT EXISTS normalized_name VARCHAR(512);

COMMENT ON COLUMN leaudit_documents.biz_document_id IS '平台内部追踪号（兼容旧字段名）';
COMMENT ON COLUMN leaudit_documents.version_group_key IS '文档版本归档组键，同一名称版本链共用';
COMMENT ON COLUMN leaudit_documents.version_no IS '同一文档系列中的版本号，从 1 开始';
COMMENT ON COLUMN leaudit_documents.previous_version_id IS '上一版本文档ID';
COMMENT ON COLUMN leaudit_documents.root_version_id IS '首版本文档ID';
COMMENT ON COLUMN leaudit_documents.is_latest_version IS '是否当前最新版本';
COMMENT ON COLUMN leaudit_documents.normalized_name IS '归一化文件名（不含扩展名），用于版本匹配';

UPDATE leaudit_documents d
SET
    version_group_key = COALESCE(d.version_group_key, 'legacy-' || d.id::text),
    version_no = COALESCE(d.version_no, 1),
    root_version_id = COALESCE(d.root_version_id, d.id),
    is_latest_version = COALESCE(d.is_latest_version, true),
    normalized_name = COALESCE(
        d.normalized_name,
        NULLIF(
            trim(
                regexp_replace(
                    lower(
                        regexp_replace(
                            regexp_replace(
                                COALESCE(
                                    (
                                        SELECT f.file_name
                                        FROM leaudit_document_files f
                                        WHERE f.document_id = d.id
                                        ORDER BY f.is_active DESC, f.id DESC
                                        LIMIT 1
                                    ),
                                    ''
                                ),
                                '\.[^.]+$',
                                '',
                                ''
                            ),
                            '[[:space:]_-]+',
                            ' ',
                            'g'
                        )
                    ),
                    '(?:\(|（)\d+(?:\)|）)$|(?:[-_\s]*副本|[-_\s]*copy)$',
                    '',
                    'g'
                )
            ),
            ''
        )
    )
WHERE d.version_group_key IS NULL
   OR d.root_version_id IS NULL
   OR d.normalized_name IS NULL;

CREATE INDEX IF NOT EXISTS idx_leaudit_documents_version_group
    ON leaudit_documents(version_group_key);

CREATE INDEX IF NOT EXISTS idx_leaudit_documents_name_match
    ON leaudit_documents(type_id, region, normalized_name, is_latest_version)
    WHERE deleted_at IS NULL;

CREATE UNIQUE INDEX IF NOT EXISTS uq_leaudit_documents_latest_version_group
    ON leaudit_documents(version_group_key)
    WHERE is_latest_version = true AND deleted_at IS NULL;

COMMIT;