// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements.  See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License.  You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package fileio_test

import (
	"context"
	"log"

	"github.com/apache/beam/sdks/v2/go/pkg/beam"
	"github.com/apache/beam/sdks/v2/go/pkg/beam/io/fileio"
	"github.com/apache/beam/sdks/v2/go/pkg/beam/x/beamx"
	"github.com/apache/beam/sdks/v2/go/pkg/beam/x/debug"
)

func ExampleMatchFiles() {
	beam.Init()
	p, s := beam.NewPipelineWithRoot()

	matches := fileio.MatchFiles(s, "gs://path/to/*.gz")
	debug.Print(s, matches)

	if err := beamx.Run(context.Background(), p); err != nil {
		log.Fatalf("Failed to execute job: %v", err)
	}
}

func ExampleMatchAll() {
	beam.Init()
	p, s := beam.NewPipelineWithRoot()

	globs := beam.Create(s, "gs://path/to/sub1/*.gz", "gs://path/to/sub2/*.gz")
	matches := fileio.MatchAll(s, globs)
	debug.Print(s, matches)

	if err := beamx.Run(context.Background(), p); err != nil {
		log.Fatalf("Failed to execute job: %v", err)
	}
}

func ExampleReadMatches() {
	beam.Init()
	p, s := beam.NewPipelineWithRoot()

	pairFn := func(ctx context.Context, file fileio.ReadableFile, emit func(string, string)) error {
		contents, err := file.ReadString(ctx)
		if err != nil {
			return err
		}
		emit(file.Metadata.Path, contents)
		return nil
	}

	matches := fileio.MatchFiles(s, "gs://path/to/*.gz")
	files := fileio.ReadMatches(s, matches)
	pairs := beam.ParDo(s, pairFn, files)
	debug.Print(s, pairs)

	if err := beamx.Run(context.Background(), p); err != nil {
		log.Fatalf("Failed to execute job: %v", err)
	}
}
