using Microsoft.EntityFrameworkCore.Migrations;

#nullable disable

namespace Iceshrimp.Backend.Core.Database.Migrations
{
    /// <inheritdoc />
    public partial class RemoveNoteDescendantsDbFunction : Migration
    { 
	    protected override void Up(MigrationBuilder migrationBuilder)
        {
	        migrationBuilder.Sql("DROP FUNCTION IF EXISTS public.note_descendants;");
        }

        /// <inheritdoc />
        protected override void Down(MigrationBuilder migrationBuilder)
        {
	        migrationBuilder.Sql("""
	                             DROP FUNCTION IF EXISTS public.note_descendants;
	                             CREATE FUNCTION public.note_descendants (start_id character varying, max_depth integer, max_breadth integer)
	                             	RETURNS SETOF "note"
	                             	LANGUAGE sql
	                             	AS $function$
	                             	SELECT
	                             		*
	                             	FROM
	                             		"note"
	                             	WHERE
	                             		id IN( SELECT DISTINCT
	                             				id FROM (WITH RECURSIVE tree (
	                             						id,
	                             						ancestors,
	                             						depth
	                             ) AS (
	                             						SELECT
	                             							start_id,
	                             							'{}'::VARCHAR [],
	                             							0
	                             						UNION
	                             						SELECT
	                             							note.id,
	                             							CASE WHEN note. "replyId" = tree.id THEN
	                             								tree.ancestors || note. "replyId"
	                             							ELSE
	                             								tree.ancestors || note. "renoteId"
	                             							END,
	                             							depth + 1 FROM note,
	                             							tree
	                             						WHERE (note. "replyId" = tree.id
	                             							OR(
	                             								-- get renotes but not pure renotes
	                             								note. "renoteId" = tree.id
	                             								AND(note.text IS NOT NULL
	                             									OR CARDINALITY (note. "fileIds"
	                             ) != 0
	                             	OR note. "hasPoll" = TRUE)))
	                             AND depth < max_depth)
	                             SELECT
	                             	id,
	                             	-- apply the limit per node
	                             	row_number() OVER (PARTITION BY ancestors [array_upper(ancestors, 1)]) AS nth_child FROM tree
	                             WHERE
	                             	depth > 0) AS RECURSIVE
	                             WHERE
	                             	nth_child < max_breadth)
	                             $function$;
	                             """);
        }
    }
}