unioffice/common/contenttypes.go

// Copyright 2017 FoxyUtils ehf. All rights reserved.
//
// Use of this software package and source code is governed by the terms of the
// UniDoc End User License Agreement (EULA) that is available at:
// https://unidoc.io/eula/
// A trial license code for evaluation can be obtained at https://unidoc.io.

package common

import (
	"fmt"
	"strings"
	"strconv"
	"regexp"

	"github.com/unidoc/unioffice"
	"github.com/unidoc/unioffice/schema/soo/pkg/content_types"
)

// ContentTypes is the top level "[Content_Types].xml" in a zip package.
type ContentTypes struct {
	x *content_types.Types
}

// NewContentTypes returns a wrapper around a newly constructed content-types.
func NewContentTypes() ContentTypes {
	ct := ContentTypes{x: content_types.NewTypes()}
	// add content type defaults
	ct.AddDefault("xml", "application/xml")
	ct.AddDefault("rels", "application/vnd.openxmlformats-package.relationships+xml")
	ct.AddDefault("png", "image/png")
	ct.AddDefault("jpeg", "image/jpeg")
	ct.AddDefault("jpg", "image/jpg")
	ct.AddDefault("wmf", "image/x-wmf")

	ct.AddOverride("/docProps/core.xml", "application/vnd.openxmlformats-package.core-properties+xml")
	ct.AddOverride("/docProps/app.xml", "application/vnd.openxmlformats-officedocument.extended-properties+xml")

	return ct
}

// X returns the inner raw content types.
func (c ContentTypes) X() *content_types.Types {
	return c.x
}

// AddDefault registers a default content type for a given file extension.
func (c ContentTypes) AddDefault(fileExtension string, contentType string) {
	def := content_types.NewDefault()
	def.ExtensionAttr = fileExtension
	def.ContentTypeAttr = contentType
	c.x.Default = append(c.x.Default, def)
}

// AddOverride adds an override content type for a given path name.
func (c ContentTypes) AddOverride(path, contentType string) {
	if !strings.HasPrefix(path, "/") {
		path = "/" + path
	}
	if strings.HasPrefix(contentType, "http") {
		unioffice.Log("content type '%s' is incorrect, must not start with http", contentType)
	}
	or := content_types.NewOverride()
	or.PartNameAttr = path
	or.ContentTypeAttr = contentType
	c.x.Override = append(c.x.Override, or)
}

// EnsureDefault esnures that an extension and default content type exist,
// adding it if necessary.
func (c ContentTypes) EnsureDefault(ext, contentType string) {
	for _, def := range c.x.Default {
		if def.ExtensionAttr == ext {
			def.ContentTypeAttr = contentType
			return
		}
	}

	def := &content_types.Default{}
	def.ContentTypeAttr = contentType
	def.ExtensionAttr = ext
	c.x.Default = append(c.x.Default, def)
}

// EnsureOverride ensures that an override for the given path exists, adding it if necessary
func (c ContentTypes) EnsureOverride(path, contentType string) {
	for _, ovr := range c.x.Override {
		// found one, so just ensure the content type matches and bail
		if ovr.PartNameAttr == path {
			if strings.HasPrefix(contentType, "http") {
				unioffice.Log("content type '%s' is incorrect, must not start with http", contentType)
			}
			ovr.ContentTypeAttr = contentType
			return
		}
	}

	// Didn't find a matching override for the target path, so add one
	c.AddOverride(path, contentType)
}

// RemoveOverride removes an override given a path.
func (c ContentTypes) RemoveOverride(path string) {
	if !strings.HasPrefix(path, "/") {
		path = "/" + path
	}
	for i, ovr := range c.x.Override {
		if ovr.PartNameAttr == path {
			copy(c.x.Override[i:], c.x.Override[i+1:])
			c.x.Override = c.x.Override[0 : len(c.x.Override)-1]
		}
	}
}

// RemoveOverrideByIndex removes an override given a path and override index.
func (c ContentTypes) RemoveOverrideByIndex(path string, indexToFind int) error {
	pathPrefix := path[0:len(path)-5] // cut off '0.xml' from the end
	if !strings.HasPrefix(pathPrefix, "/") {
		pathPrefix = "/" + pathPrefix
	}

	re, err := regexp.Compile(pathPrefix + "([0-9]+).xml")
	if err != nil {
		return err
	}
	index := 0
	indexToRemove := -1

	for i, ovr := range c.x.Override {
		if submatch := re.FindStringSubmatch(ovr.PartNameAttr); len(submatch) > 1 {
			if index == indexToFind {
				indexToRemove = i
			} else if index > indexToFind {
				newId, _ := strconv.Atoi(submatch[1])
				newId--
				ovr.PartNameAttr = fmt.Sprintf("%s%d.xml", pathPrefix, newId)
			}
			index++
		}
	}
	if indexToRemove > -1 {
		copy(c.x.Override[indexToRemove:], c.x.Override[indexToRemove+1:])
		c.x.Override = c.x.Override[0 : len(c.x.Override)-1]
	}
	return nil
}

// CopyOverride copies override content type for a given `path` and puts it with a path `newPath`.
func (c ContentTypes) CopyOverride(path, newPath string) {
	if !strings.HasPrefix(path, "/") {
		path = "/" + path
	}

	if !strings.HasPrefix(newPath, "/") {
		newPath = "/" + newPath
	}

	for i := range c.x.Override {
		if c.x.Override[i].PartNameAttr == path {
			copied := *c.x.Override[i]

			copied.PartNameAttr = newPath

			c.x.Override = append(c.x.Override, &copied)
		}
	}
}