Kepub support and skip indexing already indexed docs

README.md

@@ -18,6 +18,7 @@ A personal documents server, Coreander indexes the documents (EPUBs and PDFs wit
 * Read indexed epubs and PDFs from Coreander's interface thanks to [foliate-js](https://github.com/johnfactotum/foliate-js).
 * Restrictable access only to registered users.
 * Upload documents through the web interface.
+* Download as kepub (epub for Kobo devices) converted on the fly thanks to [Kepubify](https://github.com/pgaskin/kepubify).
 
 ## Installation
 
@@ -97,7 +98,7 @@ On first run, Coreander creates an admin user with the following credentials:
 * `PORT`: Port number in which the webserver listens for requests. Defaults to 3000.
 * `BATCH_SIZE`: Number of documents persisted by the indexer in one write operation. Defaults to 100.
 * `COVER_MAX_WIDTH`: Maximum horizontal size for documents cover thumbnails in pixels. Defaults to 600.
-* `SKIP_INDEXING`: Whether to bypass the indexing process or not.
+* `FORCE_INDEXING`: Whether to force indexing already indexed documents or not. Defaults to false.
 * `SMTP_SERVER`: Address of the send mail server.
 * `SMTP_PORT`: Port number of the send mail server. Defaults to 587.
 * `SMTP_USER`: User to authenticate against the SMTP server.

config.go

@@ -12,8 +12,8 @@ type Config struct {
 	BatchSize int `env:"BATCH_SIZE" env-default:"100"`
 	// CoverMaxWidth sets the maximum horizontal size for documents cover thumbnails in pixels
 	CoverMaxWidth int `env:"COVER_MAX_WIDTH" env-default:"600"`
-	// SkipIndexing signals whether to bypass the indexing process or not
-	SkipIndexing bool `env:"SKIP_INDEXING" env-default:"false"`
+	// ForceIndexing signals whether to force indexing already indexed documents or not
+	ForceIndexing bool `env:"FORCE_INDEXING" env-default:"false"`
 	// SmtpServer points to the address of the send mail server
 	SmtpServer string `env:"SMTP_SERVER"`
 	// SmtpPort defines the port in which the mail server listens for requests

go.mod

@@ -1,6 +1,8 @@
 module github.com/svera/coreander/v4
 
-go 1.21
+go 1.21.0
+
+toolchain go1.21.1
 
 require (
 	github.com/blevesearch/bleve/v2 v2.4.0
@@ -27,24 +29,33 @@ require (
 
 require (
 	github.com/andybalholm/cascadia v1.3.2 // indirect
+	github.com/beevik/etree v1.4.1 // indirect
 	github.com/blevesearch/go-faiss v1.0.13 // indirect
 	github.com/blevesearch/zapx/v16 v16.0.12 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/geek1011/kepubify v2.3.2+incompatible // indirect
 	github.com/glebarez/go-sqlite v1.22.0 // indirect
 	github.com/gofiber/template v1.8.3 // indirect
 	github.com/gofiber/utils v1.1.0 // indirect
 	github.com/gosimple/unidecode v1.0.1 // indirect
 	github.com/hhrutter/lzw v1.0.0 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
+	github.com/kr/smartypants v0.1.0 // indirect
 	github.com/kr/text v0.2.0 // indirect
+	github.com/mattn/go-zglob v0.0.5 // indirect
 	github.com/ncruces/go-strftime v0.1.9 // indirect
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
+	github.com/pgaskin/kepubify v2.3.2+incompatible // indirect
+	github.com/pgaskin/kepubify/_/go116-zip.go117 v0.0.0-20210611152744-2d89b3182523 // indirect
+	github.com/pgaskin/kepubify/_/html v0.0.0-20211223234002-6ee2cc632cdc // indirect
 	github.com/philhofer/fwd v1.1.2 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
 	github.com/sirupsen/logrus v1.9.3 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/tinylib/msgp v1.1.9 // indirect
+	golang.org/x/sync v0.7.0 // indirect
 	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
 	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 	modernc.org/libc v1.49.3 // indirect
@@ -90,6 +101,7 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/mschoch/smat v0.2.0 // indirect
+	github.com/pgaskin/kepubify/v4 v4.0.4
 	github.com/pirmd/epub v0.3.0
 	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect

go.sum

@@ -16,6 +16,10 @@ github.com/antzucaro/matchr v0.0.0-20210222213004-b04723ef80f0 h1:R/qAiUxFT3mNgQ
 github.com/antzucaro/matchr v0.0.0-20210222213004-b04723ef80f0/go.mod h1:v3ZDlfVAL1OrkKHbGSFFK60k0/7hruHPDq2XMs9Gu6U=
 github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
+github.com/bamiaux/rez v0.0.0-20170731184118-29f4463c688b/go.mod h1:obBQGGIFbbv9KWg92Qu9UHeD94JXmHD1jovY/z6I3O8=
+github.com/beevik/etree v1.1.0/go.mod h1:r8Aw8JqVegEf0w2fDnATrX9VpkMcyFeM0FhwO62wh+A=
+github.com/beevik/etree v1.4.1 h1:PmQJDDYahBGNKDcpdX8uPy1xRCwoCGVUiW669MEirVI=
+github.com/beevik/etree v1.4.1/go.mod h1:gPNJNaBGVZ9AwsidazFZyygnd+0pAU38N4D+WemwKNs=
 github.com/bits-and-blooms/bitset v1.12.0/go.mod h1:7hO7Gc7Pp1vODcmWvKMRA9BNmbv6a/7QIWpPxHddWR8=
 github.com/bits-and-blooms/bitset v1.13.0 h1:bAQ9OPNFYbGHV6Nez0tmNI0RiEu7/hxlYJRUA0wFAVE=
 github.com/bits-and-blooms/bitset v1.13.0/go.mod h1:7hO7Gc7Pp1vODcmWvKMRA9BNmbv6a/7QIWpPxHddWR8=
@@ -67,6 +71,8 @@ github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkp
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/flotzilla/pdf_parser v0.1.96 h1:SlgvO7NZqFzhBO+o6X1u7rUYjhv+81V3dYQF+LTfGOE=
 github.com/flotzilla/pdf_parser v0.1.96/go.mod h1:/CPB1OWEeFqRbtnFWXgArmOnA3u7smVHxr5dFy4U6Nk=
+github.com/geek1011/kepubify v2.3.2+incompatible h1:G1dAwpTpSHN79/bOqQ64SjkllYPhpp25kUkJ95WNFnA=
+github.com/geek1011/kepubify v2.3.2+incompatible/go.mod h1:xMWLgn5FQSh6oNcq//MwSwPf2WgyQq6T+fY9nSn9+Cs=
 github.com/glebarez/go-sqlite v1.22.0 h1:uAcMJhaA6r3LHMTFgP0SifzgXg46yJkgxqyuyec+ruQ=
 github.com/glebarez/go-sqlite v1.22.0/go.mod h1:PlBIdHe0+aUEFn+r2/uthrWq4FxbzugL0L8Li6yQJbc=
 github.com/glebarez/sqlite v1.11.0 h1:wSG0irqzP6VurnMEpFGer5Li19RpIRi2qvQz++w0GMw=
@@ -104,6 +110,7 @@ github.com/gosimple/slug v1.14.0 h1:RtTL/71mJNDfpUbCOmnf/XFkzKRtD6wL6Uy+3akm4Es=
 github.com/gosimple/slug v1.14.0/go.mod h1:UiRaFH+GEilHstLUmcBgWcI42viBN7mAb818JrYOeFQ=
 github.com/gosimple/unidecode v1.0.1 h1:hZzFTMMqSswvf0LBJZCZgThIZrpDHFXux9KeGmn6T/o=
 github.com/gosimple/unidecode v1.0.1/go.mod h1:CP0Cr1Y1kogOtx0bJblKzsVWrqYaqfNOnHzpgWw4Awc=
+github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/hhrutter/lzw v1.0.0 h1:laL89Llp86W3rRs83LvKbwYRx6INE8gDn0XNb1oXtm0=
 github.com/hhrutter/lzw v1.0.0/go.mod h1:2HC6DJSn/n6iAZfgM3Pg+cP1KxeWc3ezG8bBqW5+WEo=
 github.com/hhrutter/tiff v1.0.1 h1:MIus8caHU5U6823gx7C6jrfoEvfSTGtEFRiM8/LOzC0=
@@ -122,6 +129,8 @@ github.com/klauspost/compress v1.16.3/go.mod h1:ntbaceVETuRiXiv4DpjP66DpAtAGkEQs
 github.com/klauspost/compress v1.17.8 h1:YcnTYrq7MikUT7k0Yb5eceMmALQPYBW/Xltxn0NAMnU=
 github.com/klauspost/compress v1.17.8/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/smartypants v0.1.0 h1:Sn8hn5XrY+uXrxSWUdcr621Gfpk11mOGGVs4XX06kEw=
+github.com/kr/smartypants v0.1.0/go.mod h1:EcTX9ge+SWNaGwbQvHwNICsMGavh98FLUqyOWFr+j9c=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
@@ -138,6 +147,9 @@ github.com/mattn/go-runewidth v0.0.13/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh
 github.com/mattn/go-runewidth v0.0.14/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZgg3U=
 github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/mattn/go-sqlite3 v1.14.12/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
+github.com/mattn/go-zglob v0.0.5 h1:LKgpZXHg94zoBPDbb6aeiCs4SiQSS8otal4JnzkIvMc=
+github.com/mattn/go-zglob v0.0.5/go.mod h1:MxxjyoXXnMxfIpxTK2GAkw1w8glPsQILx3N5wrKakiY=
 github.com/microcosm-cc/bluemonday v1.0.26 h1:xbqSvqzQMeEHCqMi64VAs4d8uy6Mequs3rQ0k/Khz58=
 github.com/microcosm-cc/bluemonday v1.0.26/go.mod h1:JyzOCs9gkyQyjs+6h10UEVSe02CGwkhd72Xdqh78TWs=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -153,6 +165,15 @@ github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWb
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/pdfcpu/pdfcpu v0.7.0 h1:cd7/z7hAyyDuzdciKfNZyQ3TYreJza2DsuPdIHYURcA=
 github.com/pdfcpu/pdfcpu v0.7.0/go.mod h1:kmpD0rk8YnZj0l3qSeGBlAB+XszHUgNv//ORH/E7EYo=
+github.com/pgaskin/kepubify v2.3.2+incompatible h1:0wWWxop5T5O+p6tlZ59saC9hZYtkrXaKWLiTXmUNHHg=
+github.com/pgaskin/kepubify v2.3.2+incompatible/go.mod h1:vQR3SJUwNyKStXpUPsVcCjBZtjZ1TgYtgKb8jHMyEDg=
+github.com/pgaskin/kepubify/_/go116-zip.go117 v0.0.0-20210611152744-2d89b3182523 h1:pYGj3rKTy+TDs5Z707kT+ztjoIDCy76lc2UPkZocAFM=
+github.com/pgaskin/kepubify/_/go116-zip.go117 v0.0.0-20210611152744-2d89b3182523/go.mod h1:FNMbV/TSSnhqyzjq8jsS+VD0o/gwpuCH0dh8G1uQ/fw=
+github.com/pgaskin/kepubify/_/html v0.0.0-20211223234002-6ee2cc632cdc h1:mJk4TIXTO+JmxgHJ5iyil42PLQJWkyaKB/qNcjJU6h4=
+github.com/pgaskin/kepubify/_/html v0.0.0-20211223234002-6ee2cc632cdc/go.mod h1:fxzoIpMFAReNKunZ+ttVbf3hNVrJGtrSZMI4olZizbs=
+github.com/pgaskin/kepubify/v4 v4.0.4 h1:8ePyepo4eRNSmeDs5MdJLJtit+zxmK36wILmGcvpccU=
+github.com/pgaskin/kepubify/v4 v4.0.4/go.mod h1:wzUdFNYW2uZh2xfHDuzNRRUO4WqV+y99UBxVd3rBTus=
+github.com/pgaskin/koboutils/v2 v2.1.2-0.20220306004009-a07e72ebae42/go.mod h1:wTzkDIlsxmUyfwfspGcm0Ap+HOxSUYV0S8kMYrf+0gM=
 github.com/philhofer/fwd v1.1.1/go.mod h1:gk3iGcWd9+svBvR0sR+KPcfE+RNWozjowpeBVG3ZVNU=
 github.com/philhofer/fwd v1.1.2 h1:bnDivRJ1EWPjUIRXV5KfORO897HTbpFAQddBdE8t7Gw=
 github.com/philhofer/fwd v1.1.2/go.mod h1:qkPdfjR2SIEbspLqpe1tO4n5yICnr2DY7mqEx2tUTP0=
@@ -181,6 +202,8 @@ github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ
 github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/spf13/afero v1.11.0 h1:WJQKhtpdm3v2IzqG8VMqrr6Rf3UYpEF239Jy9wNepM8=
 github.com/spf13/afero v1.11.0/go.mod h1:GH9Y3pIexgf1MTIWtNGyogA5MwRIDXGUr+hbWNoBjkY=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
@@ -235,6 +258,7 @@ golang.org/x/net v0.24.0 h1:1PcaxkF854Fu3+lvBIx5SYn9wRlBzzcnHZSiaFFAb0w=
 golang.org/x/net v0.24.0/go.mod h1:2Q7sJY5mzlzWjKtYUEXSlBWCdyaioyXzRB2RtU8KVE8=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=

internal/index/bleve_test.go

@@ -35,7 +35,7 @@ func TestIndexAndSearch(t *testing.T) {
 			appFS.MkdirAll("lib", 0755)
 			afero.WriteFile(appFS, tcase.filename, []byte(""), 0644)
 
-			err = idx.AddLibrary(1)
+			err = idx.AddLibrary(1, true)
 			if err != nil {
 				t.Errorf("Error indexing: %s", err.Error())
 			}

internal/index/bleve_write.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	index "github.com/blevesearch/bleve_index_api"
 	"github.com/gosimple/slug"
 	"github.com/spf13/afero"
 	"github.com/svera/coreander/v4/internal/metadata"
@@ -45,13 +46,19 @@ func (b *BleveIndexer) RemoveFile(file string) error {
 	return nil
 }
 
-// AddLibrary scans <libraryPath> for documents and adds them to the index in batches of <bathSize>
-func (b *BleveIndexer) AddLibrary(batchSize int) error {
+// AddLibrary scans <libraryPath> for documents and adds them to the index in batches of <batchSize> if they
+// haven't been previously indexed or if <forceIndexing> is true
+func (b *BleveIndexer) AddLibrary(batchSize int, forceIndexing bool) error {
 	batch := b.idx.NewBatch()
 	batchSlugs := make(map[string]struct{}, batchSize)
 	languages := []string{}
 	b.indexStartTime = float64(time.Now().UnixNano())
 	e := afero.Walk(b.fs, b.libraryPath, func(fullPath string, f os.FileInfo, err error) error {
+		if indexed, lang := b.isAlreadyIndexed(fullPath); indexed && !forceIndexing {
+			b.indexedDocuments += 1
+			languages = addLanguage(lang, languages)
+			return nil
+		}
 		ext := strings.ToLower(filepath.Ext(fullPath))
 		if _, ok := b.reader[ext]; !ok {
 			return nil
@@ -80,13 +87,33 @@ func (b *BleveIndexer) AddLibrary(batchSize int) error {
 		}
 		return nil
 	})
+	if len(languages) > 0 {
+		batch.SetInternal(internalLanguages, []byte(strings.Join(languages, ",")))
+	}
+	b.idx.Batch(batch)
 	b.indexStartTime = 0
 	b.indexedDocuments = 0
-	batch.SetInternal(internalLanguages, []byte(strings.Join(languages, ",")))
-	b.idx.Batch(batch)
 	return e
 }
 
+func (b *BleveIndexer) isAlreadyIndexed(fullPath string) (bool, string) {
+	doc, err := b.idx.Document(b.id(fullPath))
+	if err != nil {
+		log.Fatalln(err)
+	}
+	if doc == nil {
+		return false, ""
+	}
+	lang := ""
+	doc.VisitFields(func(f index.Field) {
+		if f.Name() == "Language" {
+			lang = string(f.Value())
+			return
+		}
+	})
+	return true, lang
+}
+
 func addLanguage(lang string, languages []string) []string {
 	if !slices.Contains(languages, defaultAnalyzer) && lang == "" {
 		return append(languages, defaultAnalyzer)
@@ -117,7 +144,7 @@ func (b *BleveIndexer) createDocument(meta metadata.Metadata, fullPath string, b
 		SubjectsEq: make([]string, len(meta.Subjects)),
 	}
 
-	document.ID = b.ID(document, fullPath)
+	document.ID = b.id(fullPath)
 	document.Slug = b.Slug(document, batchSlugs)
 	copy(document.AuthorsEq, meta.Authors)
 	for i := range document.AuthorsEq {
@@ -161,7 +188,7 @@ func (b *BleveIndexer) Slug(document DocumentWrite, batchSlugs map[string]struct
 	}
 }
 
-func (b *BleveIndexer) ID(meta DocumentWrite, file string) string {
+func (b *BleveIndexer) id(file string) string {
 	ID := strings.ReplaceAll(file, b.libraryPath, "")
 	return strings.TrimPrefix(ID, string(filepath.Separator))
 }

internal/webserver/controller/document/download.go

@@ -1,16 +1,27 @@
 package document
 
 import (
+	"archive/zip"
+	"bytes"
+	"context"
 	"fmt"
 	"io"
+	"log"
 	"os"
 	"path/filepath"
 	"strings"
 
 	"github.com/gofiber/fiber/v2"
+	"github.com/pgaskin/kepubify/v4/kepub"
 )
 
 func (d *Controller) Download(c *fiber.Ctx) error {
+	var (
+		output   []byte
+		err      error
+		fileName string
+	)
+
 	document, err := d.idx.Document(c.Params("slug"))
 	if err != nil {
 		return fiber.ErrBadRequest
@@ -22,13 +33,25 @@ func (d *Controller) Download(c *fiber.Ctx) error {
 		return fiber.ErrNotFound
 	}
 
-	file, err := os.Open(fullPath)
-	if err != nil {
-		return fiber.ErrInternalServerError
-	}
-	contents, err := io.ReadAll(file)
-	if err != nil {
-		return fiber.ErrInternalServerError
+	if c.Query("format") == "kepub" {
+		output, err = kepubify(fullPath)
+		if err != nil {
+			log.Println(err)
+			return fiber.ErrInternalServerError
+		}
+		fileName = strings.TrimSuffix(filepath.Base(fullPath), filepath.Ext(fullPath))
+		fileName = fileName + ".kepub.epub"
+	} else {
+		file, err := os.Open(fullPath)
+		if err != nil {
+			log.Println(err)
+			return fiber.ErrInternalServerError
+		}
+		if output, err = io.ReadAll(file); err != nil {
+			log.Println(err)
+			return fiber.ErrInternalServerError
+		}
+		fileName = filepath.Base(document.ID)
 	}
 
 	ext := strings.ToLower(filepath.Ext(document.ID))
@@ -39,7 +62,22 @@ func (d *Controller) Download(c *fiber.Ctx) error {
 		c.Response().Header.Set(fiber.HeaderContentType, "application/pdf")
 	}
 
-	c.Response().Header.Set(fiber.HeaderContentDisposition, fmt.Sprintf("inline; filename=\"%s\"", filepath.Base(document.ID)))
-	c.Response().BodyWriter().Write(contents)
+	c.Response().Header.Set(fiber.HeaderContentDisposition, fmt.Sprintf("inline; filename=\"%s\"", fileName))
+	c.Response().BodyWriter().Write(output)
 	return nil
 }
+
+func kepubify(fullPath string) ([]byte, error) {
+	output := bytes.NewBuffer(nil)
+	r, err := zip.OpenReader(fullPath)
+	if err != nil {
+		return nil, fiber.ErrInternalServerError
+	}
+	defer r.Close()
+
+	if err = kepub.NewConverter().Convert(context.Background(), output, r); err != nil {
+		return nil, fiber.ErrInternalServerError
+	}
+
+	return output.Bytes(), nil
+}

internal/webserver/controller/document/search.go

@@ -1,6 +1,7 @@
 package document
 
 import (
+	"log"
 	"strconv"
 
 	"github.com/gofiber/fiber/v2"
@@ -35,6 +36,7 @@ func (d *Controller) Search(c *fiber.Ctx) error {
 
 	if keywords := c.Query("search"); keywords != "" {
 		if searchResults, err = d.idx.Search(keywords, page, model.ResultsPerPage); err != nil {
+			log.Println(err)
 			return fiber.ErrInternalServerError
 		}
 

internal/webserver/controller/document/send.go

@@ -1,6 +1,7 @@
 package document
 
 import (
+	"log"
 	"net/mail"
 	"os"
 	"path/filepath"
@@ -10,21 +11,23 @@ import (
 )
 
 func (d *Controller) Send(c *fiber.Ctx) error {
-	if strings.Trim(c.FormValue("slug"), " ") == "" {
+	slug := ""
+	if slug = strings.Trim(c.Params("slug"), " "); slug == "" {
 		return fiber.ErrBadRequest
 	}
 
 	if _, err := mail.ParseAddress(c.FormValue("email")); err != nil {
 		return fiber.ErrBadRequest
 	}
 
-	document, err := d.idx.Document(c.FormValue("slug"))
+	document, err := d.idx.Document(slug)
 	if err != nil {
 		return fiber.ErrBadRequest
 	}
 
 	if _, err := os.Stat(filepath.Join(d.config.LibraryPath, document.ID)); err != nil {
-		return fiber.ErrBadRequest
+		log.Println(err)
+		return fiber.ErrInternalServerError
 	}
 
 	return d.sender.SendDocument(c.FormValue("email"), d.config.LibraryPath, document.ID)