/*
	Copyright 2020 The pdfcpu Authors.

	Licensed 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 api

import (
	"io"
	"os"

	"gitee.com/deeao/golang-pdfcpu/pkg/pdfcpu"
	"gitee.com/deeao/golang-pdfcpu/pkg/pdfcpu/model"
	"github.com/pkg/errors"
)

// Keywords returns the keywords of rs's info dict.
func Keywords(rs io.ReadSeeker, conf *model.Configuration) ([]string, error) {
	if rs == nil {
		return nil, errors.New("pdfcpu: ListKeywords: missing rs")
	}

	if conf == nil {
		conf = model.NewDefaultConfiguration()
	} else {
		conf.ValidationMode = model.ValidationRelaxed
	}
	conf.Cmd = model.LISTKEYWORDS

	ctx, err := ReadValidateAndOptimize(rs, conf)
	if err != nil {
		return nil, err
	}

	return pdfcpu.KeywordsList(ctx)
}

// AddKeywords adds keywords to rs's infodict and writes the result to w.
func AddKeywords(rs io.ReadSeeker, w io.Writer, files []string, conf *model.Configuration) error {
	if rs == nil {
		return errors.New("pdfcpu: AddKeywords: missing rs")
	}

	if conf == nil {
		conf = model.NewDefaultConfiguration()
	} else {
		conf.ValidationMode = model.ValidationRelaxed
	}
	conf.Cmd = model.ADDKEYWORDS

	ctx, err := ReadValidateAndOptimize(rs, conf)
	if err != nil {
		return err
	}

	if err = pdfcpu.KeywordsAdd(ctx, files); err != nil {
		return err
	}

	return Write(ctx, w, conf)
}

// AddKeywordsFile adds keywords to inFile's infodict and writes the result to outFile.
func AddKeywordsFile(inFile, outFile string, files []string, conf *model.Configuration) (err error) {
	var f1, f2 *os.File

	if f1, err = os.Open(inFile); err != nil {
		return err
	}

	tmpFile := inFile + ".tmp"
	if outFile != "" && inFile != outFile {
		tmpFile = outFile
	}
	if f2, err = os.Create(tmpFile); err != nil {
		f1.Close()
		return err
	}

	defer func() {
		if err != nil {
			f2.Close()
			f1.Close()
			os.Remove(tmpFile)
			return
		}
		if err = f2.Close(); err != nil {
			return
		}
		if err = f1.Close(); err != nil {
			return
		}
		if outFile == "" || inFile == outFile {
			err = os.Rename(tmpFile, inFile)
		}
	}()

	return AddKeywords(f1, f2, files, conf)
}

// RemoveKeywords deletes keywords from rs's infodict and writes the result to w.
func RemoveKeywords(rs io.ReadSeeker, w io.Writer, keywords []string, conf *model.Configuration) error {
	if rs == nil {
		return errors.New("pdfcpu: RemoveKeywords: missing rs")
	}

	if conf == nil {
		conf = model.NewDefaultConfiguration()
	} else {
		conf.ValidationMode = model.ValidationRelaxed
	}
	conf.Cmd = model.REMOVEKEYWORDS

	ctx, err := ReadValidateAndOptimize(rs, conf)
	if err != nil {
		return err
	}

	var ok bool
	if ok, err = pdfcpu.KeywordsRemove(ctx, keywords); err != nil {
		return err
	}
	if !ok {
		return errors.New("no keyword removed")
	}

	return Write(ctx, w, conf)
}

// RemoveKeywordsFile deletes keywords from inFile's infodict and writes the result to outFile.
func RemoveKeywordsFile(inFile, outFile string, keywords []string, conf *model.Configuration) (err error) {
	var f1, f2 *os.File

	if f1, err = os.Open(inFile); err != nil {
		return err
	}

	tmpFile := inFile + ".tmp"
	if outFile != "" && inFile != outFile {
		tmpFile = outFile
	}
	if f2, err = os.Create(tmpFile); err != nil {
		f1.Close()
		return err
	}

	defer func() {
		if err != nil {
			f2.Close()
			f1.Close()
			os.Remove(tmpFile)
			return
		}
		if err = f2.Close(); err != nil {
			return
		}
		if err = f1.Close(); err != nil {
			return
		}
		if outFile == "" || inFile == outFile {
			err = os.Rename(tmpFile, inFile)
		}
	}()

	return RemoveKeywords(f1, f2, keywords, conf)
}