-- ============================================
-- DUAL STORAGE SUPPORT FOR DOCUMENTS
-- Store URLs for both Supabase Storage and S3 backends
-- Mirrors the avatar dual-storage pattern from migration 009
-- ============================================

-- Add local storage URL column
ALTER TABLE public.documents ADD COLUMN IF NOT EXISTS file_url_local TEXT;

-- Add S3 storage URL column
ALTER TABLE public.documents ADD COLUMN IF NOT EXISTS file_url_s3 TEXT;

-- Add storage path column (relative path used for both backends)
ALTER TABLE public.documents ADD COLUMN IF NOT EXISTS storage_path TEXT;

-- Add comments for documentation
COMMENT ON COLUMN public.documents.file_path IS 'Current active file URL (computed based on storage setting) - kept for backwards compatibility';
COMMENT ON COLUMN public.documents.file_url_local IS 'File URL when stored in Supabase Storage';
COMMENT ON COLUMN public.documents.file_url_s3 IS 'File URL when stored in S3/MinIO';
COMMENT ON COLUMN public.documents.storage_path IS 'Storage path for file (e.g., timestamp-random-filename.pdf)';

-- Migrate existing file_path values to storage_path and file_url_local
-- This handles documents uploaded before dual-storage was implemented
UPDATE public.documents
SET
  storage_path = CASE
    WHEN file_path LIKE 'http%' THEN
      -- Extract filename from URL
      CASE
        WHEN file_path LIKE '%/storage/v1/object/public/documents/%' THEN
          substring(file_path from '/storage/v1/object/public/documents/([^?]+)')
        WHEN file_path LIKE '%/documents/%' THEN
          substring(file_path from '/documents/([^?]+)')
        ELSE file_path
      END
    ELSE file_path
  END,
  file_url_local = CASE
    WHEN file_path LIKE 'http%' AND file_path LIKE '%/storage/v1/object/public/documents/%' THEN file_path
    ELSE NULL
  END,
  file_url_s3 = CASE
    WHEN file_path LIKE 'http%' AND file_path NOT LIKE '%/storage/v1/object/public/documents/%' THEN file_path
    ELSE NULL
  END
WHERE storage_path IS NULL;

-- Create index for faster lookups
CREATE INDEX IF NOT EXISTS idx_documents_storage_path ON public.documents(storage_path);