<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    /**
     * Run the migrations.
     */
    public function up(): void
    {
        Schema::table('files', function (Blueprint $table) {
            // Legacy 컬럼 nullable 변경 (하위 호환성) - 한 번에 처리
            $legacyColumns = [
                'original_name' => 'string',
                'file_name' => 'string',
                'file_name_old' => 'string',
                'fileable_id' => 'bigInteger',
                'fileable_type' => 'string',
            ];

            foreach ($legacyColumns as $column => $type) {
                if (Schema::hasColumn('files', $column)) {
                    if ($type === 'bigInteger') {
                        $table->unsignedBigInteger($column)->nullable()->change();
                    } else {
                        $table->string($column, 255)->nullable()->change();
                    }
                }
            }

            // 파일명 시스템 개선
            if (! Schema::hasColumn('files', 'display_name')) {
                $table->string('display_name', 255)->after('file_path')->comment('사용자가 보는 이름');
            }
            if (! Schema::hasColumn('files', 'stored_name')) {
                $table->string('stored_name', 255)->after('display_name')->comment('실제 저장 이름 (64bit 난수)');
            }

            // 폴더 관리
            if (! Schema::hasColumn('files', 'folder_id')) {
                $table->unsignedBigInteger('folder_id')->nullable()->after('tenant_id')->comment('folders 테이블 FK');
            }
            if (! Schema::hasColumn('files', 'is_temp')) {
                $table->boolean('is_temp')->default(true)->after('folder_id')->comment('temp 폴더 여부');
            }

            // 파일 분류
            if (! Schema::hasColumn('files', 'file_type')) {
                $table->enum('file_type', ['document', 'image', 'excel', 'archive'])->after('mime_type')->comment('파일 타입');
            }

            // 문서 연결
            if (! Schema::hasColumn('files', 'document_id')) {
                $table->unsignedBigInteger('document_id')->nullable()->after('file_type')->comment('문서 ID');
            }
            if (! Schema::hasColumn('files', 'document_type')) {
                $table->string('document_type', 50)->nullable()->after('document_id')->comment('문서 타입');
            }

            // 감사 컬럼
            if (! Schema::hasColumn('files', 'uploaded_by')) {
                $table->unsignedBigInteger('uploaded_by')->nullable()->after('description')->comment('업로더 user_id');
            }
            if (! Schema::hasColumn('files', 'deleted_by')) {
                $table->unsignedBigInteger('deleted_by')->nullable()->after('deleted_at')->comment('삭제자 user_id');
            }
            if (! Schema::hasColumn('files', 'created_by')) {
                $table->unsignedBigInteger('created_by')->nullable()->after('deleted_by')->comment('생성자 user_id');
            }
            if (! Schema::hasColumn('files', 'updated_by')) {
                $table->unsignedBigInteger('updated_by')->nullable()->after('created_by')->comment('수정자 user_id');
            }
        });

        // 인덱스 추가
        Schema::table('files', function (Blueprint $table) {
            $table->index(['tenant_id', 'folder_id'], 'idx_tenant_folder');
            $table->index('is_temp');
            $table->index('document_id');
            $table->index('created_at');
            $table->index('stored_name');
        });
    }

    /**
     * Reverse the migrations.
     */
    public function down(): void
    {
        // 인덱스 삭제 (에러 무시)
        try {
            Schema::table('files', function (Blueprint $table) {
                $table->dropIndex('idx_tenant_folder');
            });
        } catch (\Exception $e) {
            // 인덱스가 없으면 무시
        }

        try {
            Schema::table('files', function (Blueprint $table) {
                $table->dropIndex(['is_temp']);
            });
        } catch (\Exception $e) {
            // 인덱스가 없으면 무시
        }

        try {
            Schema::table('files', function (Blueprint $table) {
                $table->dropIndex(['document_id']);
            });
        } catch (\Exception $e) {
            // 인덱스가 없으면 무시
        }

        try {
            Schema::table('files', function (Blueprint $table) {
                $table->dropIndex(['created_at']);
            });
        } catch (\Exception $e) {
            // 인덱스가 없으면 무시
        }

        try {
            Schema::table('files', function (Blueprint $table) {
                $table->dropIndex(['stored_name']);
            });
        } catch (\Exception $e) {
            // 인덱스가 없으면 무시
        }

        // 컬럼 삭제 (존재하는 것만)
        Schema::table('files', function (Blueprint $table) {
            $columnsToCheck = [
                'display_name',
                'stored_name',
                'folder_id',
                'is_temp',
                'file_type',
                'document_id',
                'document_type',
                'uploaded_by',
                'deleted_by',
                'created_by',
                'updated_by',
            ];

            $columnsToDrop = [];
            foreach ($columnsToCheck as $column) {
                if (Schema::hasColumn('files', $column)) {
                    $columnsToDrop[] = $column;
                }
            }

            if (! empty($columnsToDrop)) {
                $table->dropColumn($columnsToDrop);
            }
        });
    }
};