-- Add approved_at column to submission_items table
ALTER TABLE submission_items 
ADD COLUMN approved_at timestamp with time zone;

-- Add index for analytics queries (filtered index for performance)
CREATE INDEX idx_submission_items_approved_at 
ON submission_items(approved_at) 
WHERE approved_at IS NOT NULL;

-- Add comment for documentation
COMMENT ON COLUMN submission_items.approved_at IS 
  'Timestamp when this specific item was approved by a moderator. NULL for pending/rejected items.';

-- Drop existing function to update parameter signature
DROP FUNCTION IF EXISTS process_approval_transaction(UUID, UUID[], UUID, UUID, TEXT, TEXT, TEXT);

-- Recreate process_approval_transaction function with approved_at support
CREATE OR REPLACE FUNCTION process_approval_transaction(
  p_submission_id UUID,
  p_item_ids UUID[],
  p_moderator_id UUID,
  p_submitter_id UUID,
  p_request_id TEXT DEFAULT NULL,
  p_approval_mode TEXT DEFAULT 'full',
  p_idempotency_key TEXT DEFAULT NULL
) RETURNS JSONB AS $$
DECLARE
  v_item RECORD;
  v_entity_id UUID;
  v_entity_type TEXT;
  v_action_type TEXT;
  v_item_data JSONB;
  v_approved_items JSONB := '[]'::JSONB;
  v_failed_items JSONB := '[]'::JSONB;
  v_submission_type TEXT;
  v_result JSONB;
  v_error_message TEXT;
  v_error_detail TEXT;
  v_start_time TIMESTAMP := clock_timestamp();
  v_duration_ms INTEGER;
  v_rollback_triggered BOOLEAN := FALSE;
  v_lock_acquired BOOLEAN := FALSE;
BEGIN
  -- Validate moderator has permission
  IF NOT is_moderator(p_moderator_id) THEN
    RAISE EXCEPTION 'User % does not have moderator privileges', p_moderator_id
      USING ERRCODE = 'insufficient_privilege';
  END IF;

  -- Get submission type
  SELECT submission_type INTO v_submission_type
  FROM content_submissions
  WHERE id = p_submission_id;

  IF v_submission_type IS NULL THEN
    RAISE EXCEPTION 'Submission % not found', p_submission_id
      USING ERRCODE = 'no_data_found';
  END IF;

  -- Acquire advisory lock
  IF NOT pg_try_advisory_xact_lock(hashtext(p_submission_id::TEXT)) THEN
    RAISE EXCEPTION 'Could not acquire lock for submission %', p_submission_id
      USING ERRCODE = '55P03';
  END IF;
  v_lock_acquired := TRUE;

  -- Process each item
  FOR v_item IN
    SELECT si.*
    FROM submission_items si
    WHERE si.submission_id = p_submission_id
      AND si.id = ANY(p_item_ids)
      AND si.status = 'pending'
    ORDER BY si.order_index
  LOOP
    BEGIN
      v_entity_type := v_item.item_type;
      v_action_type := v_item.action_type;
      v_item_data := v_item.item_data;

      -- Create/update entity based on type and action
      IF v_action_type = 'create' THEN
        IF v_entity_type = 'park' THEN
          INSERT INTO parks (name, slug, description, location_id, operator_id, property_owner_id)
          SELECT 
            v_item_data->>'name',
            v_item_data->>'slug',
            v_item_data->>'description',
            (v_item_data->>'location_id')::UUID,
            (v_item_data->>'operator_id')::UUID,
            (v_item_data->>'property_owner_id')::UUID
          RETURNING id INTO v_entity_id;

        ELSIF v_entity_type = 'ride' THEN
          INSERT INTO rides (name, slug, park_id, manufacturer_id, designer_id)
          SELECT 
            v_item_data->>'name',
            v_item_data->>'slug',
            (v_item_data->>'park_id')::UUID,
            (v_item_data->>'manufacturer_id')::UUID,
            (v_item_data->>'designer_id')::UUID
          RETURNING id INTO v_entity_id;

        ELSIF v_entity_type IN ('manufacturer', 'operator', 'designer', 'property_owner') THEN
          INSERT INTO companies (name, slug, company_type, description)
          SELECT 
            v_item_data->>'name',
            v_item_data->>'slug',
            v_entity_type,
            v_item_data->>'description'
          RETURNING id INTO v_entity_id;

        ELSE
          RAISE EXCEPTION 'Unsupported entity type: %', v_entity_type;
        END IF;

      ELSIF v_action_type = 'edit' THEN
        v_entity_id := (v_item_data->>'entity_id')::UUID;
        
        IF v_entity_type = 'park' THEN
          UPDATE parks SET
            name = COALESCE(v_item_data->>'name', name),
            description = COALESCE(v_item_data->>'description', description),
            location_id = COALESCE((v_item_data->>'location_id')::UUID, location_id),
            updated_at = now()
          WHERE id = v_entity_id;

        ELSIF v_entity_type = 'ride' THEN
          UPDATE rides SET
            name = COALESCE(v_item_data->>'name', name),
            description = COALESCE(v_item_data->>'description', description),
            updated_at = now()
          WHERE id = v_entity_id;

        ELSIF v_entity_type IN ('manufacturer', 'operator', 'designer', 'property_owner') THEN
          UPDATE companies SET
            name = COALESCE(v_item_data->>'name', name),
            description = COALESCE(v_item_data->>'description', description),
            updated_at = now()
          WHERE id = v_entity_id;
        END IF;
      END IF;

      -- Update submission item with approved status and timestamp
      UPDATE submission_items
      SET 
        approved_entity_id = v_entity_id,
        status = 'approved',
        approved_at = now(),
        updated_at = now()
      WHERE id = v_item.id;

      -- Add to success list
      v_approved_items := v_approved_items || jsonb_build_object(
        'item_id', v_item.id,
        'entity_id', v_entity_id,
        'entity_type', v_entity_type
      );

    EXCEPTION WHEN OTHERS THEN
      GET STACKED DIAGNOSTICS 
        v_error_message = MESSAGE_TEXT,
        v_error_detail = PG_EXCEPTION_DETAIL;

      -- Add to failed list
      v_failed_items := v_failed_items || jsonb_build_object(
        'item_id', v_item.id,
        'error', v_error_message,
        'detail', v_error_detail
      );

      -- Mark item as failed
      UPDATE submission_items
      SET 
        status = 'flagged',
        rejection_reason = v_error_message,
        updated_at = now()
      WHERE id = v_item.id;
    END;
  END LOOP;

  -- Update submission status based on approval mode
  IF p_approval_mode = 'selective' THEN
    UPDATE content_submissions
    SET 
      status = 'partially_approved',
      reviewed_at = now(),
      reviewer_id = p_moderator_id,
      updated_at = now()
    WHERE id = p_submission_id;
  ELSE
    UPDATE content_submissions
    SET 
      status = 'approved',
      reviewed_at = now(),
      reviewer_id = p_moderator_id,
      resolved_at = now(),
      updated_at = now()
    WHERE id = p_submission_id;
  END IF;

  -- Calculate duration
  v_duration_ms := EXTRACT(EPOCH FROM (clock_timestamp() - v_start_time)) * 1000;

  -- Log metrics
  INSERT INTO approval_transaction_metrics (
    submission_id,
    moderator_id,
    submitter_id,
    items_count,
    success,
    duration_ms,
    request_id,
    rollback_triggered
  ) VALUES (
    p_submission_id,
    p_moderator_id,
    p_submitter_id,
    jsonb_array_length(v_approved_items),
    jsonb_array_length(v_failed_items) = 0,
    v_duration_ms,
    p_request_id,
    v_rollback_triggered
  );

  -- Build result
  v_result := jsonb_build_object(
    'success', TRUE,
    'approved_items', v_approved_items,
    'failed_items', v_failed_items,
    'duration_ms', v_duration_ms
  );

  RETURN v_result;

EXCEPTION WHEN OTHERS THEN
  v_rollback_triggered := TRUE;
  GET STACKED DIAGNOSTICS 
    v_error_message = MESSAGE_TEXT,
    v_error_detail = PG_EXCEPTION_DETAIL;

  -- Log failed transaction
  v_duration_ms := EXTRACT(EPOCH FROM (clock_timestamp() - v_start_time)) * 1000;
  
  INSERT INTO approval_transaction_metrics (
    submission_id,
    moderator_id,
    submitter_id,
    items_count,
    success,
    duration_ms,
    error_message,
    error_details,
    request_id,
    rollback_triggered
  ) VALUES (
    p_submission_id,
    p_moderator_id,
    p_submitter_id,
    array_length(p_item_ids, 1),
    FALSE,
    v_duration_ms,
    v_error_message,
    v_error_detail,
    p_request_id,
    v_rollback_triggered
  );

  RAISE;
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;