mail: use epub title metadata instead of file name when available

Author: rupor-github

.github/copilot-instructions.md

@@ -0,0 +1,38 @@
+---
+applyTo: "**"
+---
+
+# Project general coding standards
+
+This project uses Go (Golang) and follows standard community practices, prioritizing simplicity and clarity.
+When running prompt always assume that sources could be changed.
+
+## Naming Conventions
+*   **Variables/Functions:** Use `camelCase` for variable names and function names.
+*   **Structs/Interfaces:** Use `PascalCase` for struct names and interfaces.
+*   **Constants:** Use `ALL_CAPS` for constants.
+*   **Acronyms:** Acronyms (like `URL` or `HTTP`) should be all uppercase in names (e.g., `makeHTTPRequest`, not `makeHttpRequest`).
+*   **Private/Public:** Use lowercase first letter for package-private items; use uppercase first letter for publicly exported items.
+
+## Code Style and Formatting
+*   **Indentation:** Use tabs for indentation, not spaces (standard Go practice).
+*   **Formatting:** Always run `goimports-reviser -format -company-prefixes github.com/rupor-github ./...` before committing. Generated code should be explicitly marked and excluded from style checks.
+*   **Imports:** Use standard grouping for imports: standard library first, then third-party libraries, then local project packages, separated by blank lines.
+*   **Control flow:** Prefer early funcion exits. When possible prefer if/then to full if/then/else to avoid nesting.
+*   **Language**  Always use latest Go features.
+
+## Error Handling
+*   **Error Values:** Errors should be the last return value and have type `error`.
+*   **Error Wrapping:** Wrap errors using `fmt.Errorf` with `%w` where appropriate to preserve the original error chain.
+*   **Panics:** Avoid `panic` except for truly unrecoverable situations (e.g., a critical configuration issue at startup). Use error returns for expected failures.
+*   **Logging:** Use uber zap structured logging library for all logging (avoid `fmt.Println` in production code).
+
+## Project Structure
+*   **Dependencies:** We use [Go Modules](go.dev) for dependency management.
+*   **Testing:** Write unit tests for all new functions. Test files should have the `_test.go` suffix. Use the built-in `testing` package and `go test` runner.
+
+## Copilot Directives
+*   **Prefer standard library:** Where possible, prefer the Go standard library over external dependencies.
+*   **Concurrency:** When writing concurrent code, prioritize using channels and goroutines following Go idioms.
+*   **Code Review:** When performing a code review, focus on idiomatic Go practices, test coverage, and clear error handling.
+*   **Binaries and temporary artifacts:** Never build anything in project directory, use /tmp. Always generate temporary artifacts in the /tmp directory

.github/workflows/release.yml

@@ -33,7 +33,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
-          go-version: '1.25.1'
+          go-version: '1.25.5'
 
       - name: Build everything
         run: task release

common/epub.go

@@ -0,0 +1,82 @@
+package common
+
+import (
+	"archive/zip"
+	"encoding/xml"
+	"io"
+	"strings"
+)
+
+type epubContainer struct {
+	Rootfile struct {
+		Path string `xml:"full-path,attr"`
+	} `xml:"rootfiles>rootfile"`
+}
+
+type epubPackage struct {
+	Metadata struct {
+		Title string `xml:"http://purl.org/dc/elements/1.1/ title"`
+	} `xml:"metadata"`
+}
+
+// GetEPUBTitle extracts the title from an EPUB file
+// Returns the title if successful, empty string otherwise
+func GetEPUBTitle(epubPath string) (string, error) {
+	r, err := zip.OpenReader(epubPath)
+	if err != nil {
+		return "", err
+	}
+	defer r.Close()
+
+	// Find and read the container.xml to get the content.opf path
+	var contentPath string
+	for _, f := range r.File {
+		if f.Name == "META-INF/container.xml" {
+			rc, err := f.Open()
+			if err != nil {
+				return "", err
+			}
+			data, err := io.ReadAll(rc)
+			rc.Close()
+			if err != nil {
+				return "", err
+			}
+
+			var container epubContainer
+			if err := xml.Unmarshal(data, &container); err != nil {
+				return "", err
+			}
+			contentPath = container.Rootfile.Path
+			break
+		}
+	}
+
+	if contentPath == "" {
+		return "", nil
+	}
+
+	// Read the content.opf to get metadata
+	// Need to handle both forward and backslashes since some EPUB files use backslashes
+	contentPathAlt := strings.ReplaceAll(contentPath, "/", "\\")
+	for _, f := range r.File {
+		if f.Name == contentPath || f.Name == contentPathAlt {
+			rc, err := f.Open()
+			if err != nil {
+				return "", err
+			}
+			data, err := io.ReadAll(rc)
+			rc.Close()
+			if err != nil {
+				return "", err
+			}
+
+			var pkg epubPackage
+			if err := xml.Unmarshal(data, &pkg); err != nil {
+				return "", err
+			}
+			return strings.TrimSpace(pkg.Metadata.Title), nil
+		}
+	}
+
+	return "", nil
+}

common/epub_test.go

@@ -0,0 +1,83 @@
+package common
+
+import (
+	"archive/zip"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestGetEPUBTitle(t *testing.T) {
+	// Create a temporary EPUB file for testing
+	tmpDir := t.TempDir()
+	epubPath := filepath.Join(tmpDir, "test.epub")
+
+	// Create a minimal EPUB structure
+	zipFile, err := os.Create(epubPath)
+	if err != nil {
+		t.Fatalf("Failed to create test EPUB: %v", err)
+	}
+	defer zipFile.Close()
+
+	w := zip.NewWriter(zipFile)
+
+	// Add mimetype file
+	mimetypeFile, _ := w.Create("mimetype")
+	mimetypeFile.Write([]byte("application/epub+zip"))
+
+	// Add container.xml
+	containerFile, _ := w.Create("META-INF/container.xml")
+	containerXML := `<?xml version="1.0"?>
+<container version="1.0" xmlns="urn:oasis:names:tc:opendocument:xmlns:container">
+  <rootfiles>
+    <rootfile full-path="content.opf" media-type="application/oebps-package+xml"/>
+  </rootfiles>
+</container>`
+	containerFile.Write([]byte(containerXML))
+
+	// Add content.opf with metadata
+	contentFile, _ := w.Create("content.opf")
+	contentOPF := `<?xml version="1.0" encoding="UTF-8"?>
+<package xmlns="http://www.idpf.org/2007/opf" version="2.0">
+  <metadata xmlns:dc="http://purl.org/dc/elements/1.1/">
+    <dc:title>Test Book Title</dc:title>
+    <dc:creator>Test Author</dc:creator>
+  </metadata>
+</package>`
+	contentFile.Write([]byte(contentOPF))
+
+	w.Close()
+
+	// Test the function
+	title, err := GetEPUBTitle(epubPath)
+	if err != nil {
+		t.Fatalf("GetEPUBTitle failed: %v", err)
+	}
+
+	expectedTitle := "Test Book Title"
+	if title != expectedTitle {
+		t.Errorf("Expected title %q, got %q", expectedTitle, title)
+	}
+}
+
+func TestGetEPUBTitle_NonExistent(t *testing.T) {
+	_, err := GetEPUBTitle("/nonexistent/file.epub")
+	if err == nil {
+		t.Error("Expected error for non-existent file, got nil")
+	}
+}
+
+func TestGetEPUBTitle_InvalidZip(t *testing.T) {
+	tmpDir := t.TempDir()
+	invalidPath := filepath.Join(tmpDir, "invalid.epub")
+
+	// Create a non-zip file
+	if err := os.WriteFile(invalidPath, []byte("not a zip file"), 0644); err != nil {
+		t.Fatalf("Failed to create invalid file: %v", err)
+	}
+
+	_, err := GetEPUBTitle(invalidPath)
+	if err == nil {
+		t.Error("Expected error for invalid zip file, got nil")
+	}
+}

go.mod

@@ -1,6 +1,6 @@
 module sync2kindle
 
-go 1.25.1
+go 1.25.5
 
 tool honnef.co/go/tools/cmd/staticcheck
 
@@ -9,46 +9,43 @@ require (
 	github.com/disintegration/imaging v1.6.2
 	github.com/dustin/go-humanize v1.0.1
 	github.com/go-ole/go-ole v1.3.0
-	github.com/go-playground/validator/v10 v10.27.0
+	github.com/go-playground/validator/v10 v10.29.0
 	github.com/gosimple/slug v1.15.0
-	github.com/rupor-github/gencfg v1.0.7
-	github.com/urfave/cli/v3 v3.4.1
-	go.uber.org/zap v1.27.0
-	golang.org/x/sys v0.36.0
-	golang.org/x/term v0.35.0
+	github.com/rupor-github/gencfg v1.0.13
+	github.com/urfave/cli/v3 v3.6.1
+	go.uber.org/zap v1.27.1
+	golang.org/x/sys v0.39.0
+	golang.org/x/term v0.38.0
 	gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df
 	gopkg.in/yaml.v3 v3.0.1
 	zombiezen.com/go/sqlite v1.4.2
 )
 
 require (
 	github.com/BurntSushi/toml v1.5.0 // indirect
-	github.com/gabriel-vasile/mimetype v1.4.10 // indirect
+	github.com/gabriel-vasile/mimetype v1.4.12 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/go-task/slim-sprig/v3 v3.0.0 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/gosimple/unidecode v1.0.1 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
-	github.com/ncruces/go-strftime v0.1.9 // indirect
+	github.com/ncruces/go-strftime v1.0.0 // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
-	github.com/stretchr/testify v1.11.1 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
-	golang.org/x/crypto v0.42.0 // indirect
-	golang.org/x/exp v0.0.0-20250911091902-df9299821621 // indirect
-	golang.org/x/exp/typeparams v0.0.0-20250911091902-df9299821621 // indirect
-	golang.org/x/image v0.31.0 // indirect
-	golang.org/x/mod v0.28.0 // indirect
-	golang.org/x/sync v0.17.0 // indirect
-	golang.org/x/text v0.29.0 // indirect
-	golang.org/x/tools v0.37.0 // indirect
+	golang.org/x/crypto v0.46.0 // indirect
+	golang.org/x/exp v0.0.0-20251209150349-8475f28825e9 // indirect
+	golang.org/x/exp/typeparams v0.0.0-20251209150349-8475f28825e9 // indirect
+	golang.org/x/image v0.34.0 // indirect
+	golang.org/x/mod v0.31.0 // indirect
+	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/text v0.32.0 // indirect
+	golang.org/x/tools v0.40.0 // indirect
 	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
 	honnef.co/go/tools v0.6.1 // indirect
-	modernc.org/cc/v4 v4.26.5 // indirect
-	modernc.org/fileutil v1.3.33 // indirect
-	modernc.org/libc v1.66.9 // indirect
+	modernc.org/libc v1.67.1 // indirect
 	modernc.org/mathutil v1.7.1 // indirect
 	modernc.org/memory v1.11.0 // indirect
-	modernc.org/sqlite v1.39.0 // indirect
+	modernc.org/sqlite v1.40.1 // indirect
 )