feat: cross-platform support (Windows, macOS scaffolding)

.github/workflows/windows.yml

@@ -0,0 +1,82 @@
+name: Windows Build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    name: Windows amd64 build
+    runs-on: windows-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.24.0'
+          cache: true
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+          cache-dependency-path: frontend/package-lock.json
+
+      - name: Install frontend dependencies
+        working-directory: frontend
+        run: npm ci
+
+      - name: Build frontend
+        # Populates frontend/dist so //go:embed all:frontend/dist has assets.
+        shell: bash
+        working-directory: frontend
+        run: ./build.sh
+
+      - name: Setup MSVC environment
+        # MuPDF static libs shipped by gen2brain/go-fitz are built with MSVC,
+        # so cgo must use cl.exe to satisfy MSVC-only intrinsics like
+        # __intrinsic_setjmpex / __memcpy_chk.
+        uses: ilammy/msvc-dev-cmd@v1
+        with:
+          arch: x64
+
+      - name: Download Go dependencies
+        run: go mod download
+
+      - name: Setup go-fitz directories
+        shell: bash
+        run: |
+          GOMOD=$(go env GOMODCACHE)
+          cp -r "$GOMOD/github.com/gen2brain/go-fitz@v1.24.15/include" go-fitz-include
+          cp -r "$GOMOD/github.com/gen2brain/go-fitz@v1.24.15/libs"    go-fitz-libs
+
+      - name: Vet
+        run: go vet ./...
+
+      - name: Build
+        shell: bash
+        env:
+          CGO_ENABLED: "1"
+          CGO_CFLAGS: "-I${{ github.workspace }}/go-fitz-include"
+          CGO_LDFLAGS: "-L${{ github.workspace }}/go-fitz-libs -lmupdf_windows_amd64 -lmupdfthird_windows_amd64"
+        run: go build -tags "desktop,production" -ldflags "-H windowsgui" -o lankir.exe .
+
+      - name: Verify artifact
+        shell: bash
+        run: |
+          test -f lankir.exe
+          file lankir.exe || true
+          ls -lh lankir.exe
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: lankir-windows-amd64
+          path: lankir.exe
+          retention-days: 14

.gitignore

@@ -2,6 +2,10 @@
 /build/
 /bin/
 
+docs/plans/
+CLAUDE.md
+TODOs.md
+
 # Scripts (temporary build files)
 /scripts/
 

Taskfile.yml

@@ -30,6 +30,26 @@ tasks:
     cmds:
       - ./scripts/build-static.sh
 
+  build-windows:
+    desc: Cross-compile a Windows amd64 CLI binary (requires mingw-w64; not the full Wails app)
+    cmds:
+      - |
+        if ! command -v x86_64-w64-mingw32-gcc >/dev/null; then
+          echo "error: mingw-w64 not installed (apt install gcc-mingw-w64-x86-64)"
+          exit 1
+        fi
+      - cd {{.FRONTEND_DIR}} && ./build.sh
+      - mkdir -p {{.BUILD_DIR}}
+      - |
+        CGO_ENABLED=1 \
+        CC=x86_64-w64-mingw32-gcc \
+        CXX=x86_64-w64-mingw32-g++ \
+        GOOS=windows GOARCH=amd64 \
+        CGO_CFLAGS="-I${PWD}/go-fitz-include" \
+        CGO_LDFLAGS="-L${PWD}/go-fitz-libs -lmupdf_windows_amd64 -lmupdfthird_windows_amd64" \
+        go build -tags "desktop,production" -ldflags "-H windowsgui" -o {{.BUILD_DIR}}/{{.BINARY_NAME}}.exe .
+      - echo "✓ Built {{.BUILD_DIR}}/{{.BINARY_NAME}}.exe"
+
   appimage:
     desc: Build a truly portable AppImage (runs on any Linux distro)
     cmds:
@@ -224,6 +244,13 @@ tasks:
       - echo "Running linters..."
       - golangci-lint run ./...
 
+  vet-cross:
+    desc: Run go vet for linux, windows and darwin to catch build-tag mistakes
+    cmds:
+      - echo "vet linux..."   && GOOS=linux   go vet ./...
+      - echo "vet windows..." && GOOS=windows go vet ./...
+      - echo "vet darwin..."  && GOOS=darwin  go vet ./...
+
   deps:
     desc: Download and verify dependencies
     cmds:

console_other.go

@@ -0,0 +1,5 @@
+//go:build !windows
+
+package main
+
+func attachParentConsole() {}

console_windows.go

@@ -0,0 +1,28 @@
+//go:build windows
+
+package main
+
+import (
+	"os"
+	"syscall"
+)
+
+// attachParentConsole reattaches stdout/stderr to the parent console on
+// Windows. The binary is built with -H windowsgui so double-clicking does not
+// flash a console window, but CLI invocation from cmd/PowerShell still needs
+// stdout to land somewhere visible. AttachConsole returns 0 if there is no
+// parent console (e.g. launched from Explorer) — that is the GUI path and we
+// silently skip rebinding.
+func attachParentConsole() {
+	const attachParentProcess = ^uintptr(0) // -1, ATTACH_PARENT_PROCESS
+	kernel32 := syscall.NewLazyDLL("kernel32.dll")
+	if r1, _, _ := kernel32.NewProc("AttachConsole").Call(attachParentProcess); r1 == 0 {
+		return
+	}
+	if h, err := syscall.GetStdHandle(syscall.STD_OUTPUT_HANDLE); err == nil && h != 0 {
+		os.Stdout = os.NewFile(uintptr(h), "stdout")
+	}
+	if h, err := syscall.GetStdHandle(syscall.STD_ERROR_HANDLE); err == nil && h != 0 {
+		os.Stderr = os.NewFile(uintptr(h), "stderr")
+	}
+}

go.mod

@@ -7,6 +7,7 @@ toolchain go1.24.10
 require (
 	github.com/digitorus/pdfsign v0.0.0-20250819064552-5f74f69dda1d
 	github.com/gen2brain/go-fitz v1.24.15
+	github.com/github/smimesign v0.2.0
 	github.com/google/uuid v1.6.0
 	github.com/miekg/pkcs11 v1.1.1
 	github.com/spf13/cobra v1.10.1
@@ -51,3 +52,5 @@ require (
 	golang.org/x/sys v0.38.0 // indirect
 	golang.org/x/text v0.30.0 // indirect
 )
+
+replace github.com/github/smimesign => github.com/nikwo/smimesign-fork v0.0.0-20221130091550-0956e442b5b6

go.sum

@@ -1,6 +1,8 @@
 github.com/bep/debounce v1.2.1 h1:v67fRdBA9UQu2NhLFXrSg0Brw7CexQekrBwDMM8bzeY=
 github.com/bep/debounce v1.2.1/go.mod h1:H8yggRPQKLUhUoqrJC1bO2xNya7vanpDl7xR3ISbCJ0=
+github.com/certifi/gocertifi v0.0.0-20180118203423-deb3ae2ef261/go.mod h1:GJKEexRPVJrBSOjoqN5VNOIKJ5Q3RViH6eu3puDRwx4=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/digitorus/pdf v0.1.2 h1:RjYEJNbiV6Kcn8QzRi6pwHuOaSieUUrg4EZo4b7KuIQ=
@@ -56,8 +58,12 @@ github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWE
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/miekg/pkcs11 v1.1.1 h1:Ugu9pdy6vAYku5DEpVWVFPYnzV+bxB+iRdbuFSu7TvU=
 github.com/miekg/pkcs11 v1.1.1/go.mod h1:XsNlhZGX73bx86s2hdc/FuaLm2CPZJemRLMA+WTFxgs=
+github.com/nikwo/smimesign-fork v0.0.0-20221130091550-0956e442b5b6 h1:3IrbV7NPAWO10w8u1j6our8+7rSblbGCsXOZ7oCvEYQ=
+github.com/nikwo/smimesign-fork v0.0.0-20221130091550-0956e442b5b6/go.mod h1:iZiiwNT4HbtGRVqCQu7uJPEZCuEE5sfSSttcnePkDl4=
+github.com/pborman/getopt v0.0.0-20180811024354-2b5b3bfb099b/go.mod h1:85jBQOZwpVEaDAr341tbn15RS4fCAsIst0qp7i8ex1o=
 github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c h1:+mdjkGKdHQG3305AYmdv1U2eRNDiU2ErMBj1gwrq8eQ=
 github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c/go.mod h1:7rwL4CYBLnjLxUqIJNnCWiEdr3bn6IUYi15bNlnbCCU=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -72,6 +78,8 @@ github.com/spf13/cobra v1.10.1 h1:lJeBwCfmrnXthfAupyUTzJ/J4Nc1RsHC/mSRU2dll/s=
 github.com/spf13/cobra v1.10.1/go.mod h1:7SmJGaTHFVBY0jW4NXGluQoLvhqFQM+6XSKD+P4XaB0=
 github.com/spf13/pflag v1.0.9 h1:9exaQaMOCwffKiiiYk6/BndUBv+iRViNW+4lEMi0PvY=
 github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/tkrajina/go-reflector v0.5.8 h1:yPADHrwmUbMq4RGEyaOUpz2H90sRsETNVpjzo3DLVQQ=
@@ -86,13 +94,18 @@ github.com/wailsapp/mimetype v1.4.1 h1:pQN9ycO7uo4vsUUuPeHEYoUkLVkaRntMnHJxVwYhw
 github.com/wailsapp/mimetype v1.4.1/go.mod h1:9aV5k31bBOv5z6u+QP8TltzvNGJPmNJD4XlAL3U+j3o=
 github.com/wailsapp/wails/v2 v2.10.2 h1:29U+c5PI4K4hbx8yFbFvwpCuvqK9VgNv8WGobIlKlXk=
 github.com/wailsapp/wails/v2 v2.10.2/go.mod h1:XuN4IUOPpzBrHUkEd7sCU5ln4T/p1wQedfxP7fKik+4=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
 golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
 golang.org/x/image v0.32.0 h1:6lZQWq75h7L5IWNk0r+SCpUJ6tUVd3v4ZHnbRKLkUDQ=
 golang.org/x/image v0.32.0/go.mod h1:/R37rrQmKXtO6tYXAjtDLwQgFLHmhW+V6ayXlxzP2Pc=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20210505024714-0287a6fb4125/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.45.0 h1:RLBg5JKixCy82FtLJpeNlVM0nrSqpCRYzVU1n8kj0tM=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200810151505-1b9f1253b3ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -102,10 +115,12 @@ golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.38.0 h1:3yZWxaJjBmCWXqhN1qh02AkOnCQ1poK6oF+a7xWL6Gc=
 golang.org/x/sys v0.38.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.30.0 h1:yznKA/E9zq54KzlzBEAWn1NXSQ8DIp/NYMy88xJjl4k=
 golang.org/x/text v0.30.0/go.mod h1:yDdHFIX9t+tORqspjENWgzaCVXgk0yYnYuSZ8UzzBVM=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/config/config.go

@@ -46,12 +46,16 @@ type Service struct {
 
 // NewService creates a config service using the default config directory.
 func NewService() (*Service, error) {
-	homeDir, err := os.UserHomeDir()
+	// Use os.UserConfigDir() for cross-platform config directory
+	// Linux: ~/.config/lankir
+	// Windows: %APPDATA%\lankir (C:\Users\<user>\AppData\Roaming\lankir)
+	// macOS: ~/Library/Application Support/lankir
+	configDir, err := os.UserConfigDir()
 	if err != nil {
-		return nil, fmt.Errorf("failed to get user home directory: %w", err)
+		return nil, fmt.Errorf("failed to get user config directory: %w", err)
 	}
 
-	configDir := filepath.Join(homeDir, ".config", "lankir")
+	configDir = filepath.Join(configDir, "lankir")
 	return NewServiceWithDir(configDir)
 }
 

internal/pdf/render_annots.go

@@ -9,42 +9,11 @@ package pdf
 /*
 #cgo CFLAGS: -I${SRCDIR}/../../go-fitz-include
 #cgo linux,amd64 LDFLAGS: -L${SRCDIR}/../../go-fitz-libs -lmupdf_linux_amd64 -lmupdfthird_linux_amd64 -lm
+#cgo windows,amd64 LDFLAGS: -L${SRCDIR}/../../go-fitz-libs -lmupdf_windows_amd64 -lmupdfthird_windows_amd64
 #include <mupdf/fitz.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
-#include <unistd.h>
-#include <fcntl.h>
-
-static int mupdf_warnings_suppressed = 0;
-static int saved_stderr = -1;
-
-// suppress_mupdf_warnings redirects stderr to /dev/null to silence MuPDF warnings
-void suppress_mupdf_warnings() {
-	if (mupdf_warnings_suppressed) return;
-
-	// Save original stderr
-	saved_stderr = dup(STDERR_FILENO);
-
-	// Redirect stderr to /dev/null
-	int devnull = open("/dev/null", O_WRONLY);
-	if (devnull != -1) {
-		dup2(devnull, STDERR_FILENO);
-		close(devnull);
-		mupdf_warnings_suppressed = 1;
-	}
-}
-
-// restore_mupdf_warnings restores stderr to show MuPDF warnings
-void restore_mupdf_warnings() {
-	if (!mupdf_warnings_suppressed || saved_stderr == -1) return;
-
-	// Restore original stderr
-	dup2(saved_stderr, STDERR_FILENO);
-	close(saved_stderr);
-	saved_stderr = -1;
-	mupdf_warnings_suppressed = 0;
-}
 
 // RenderResult contains the result of rendering
 typedef struct {
@@ -190,14 +159,17 @@ import (
 	"unsafe"
 )
 
-// SuppressMuPDFWarnings redirects MuPDF warnings to /dev/null
+// SuppressMuPDFWarnings redirects MuPDF warnings to the platform null device.
+// Not safe for concurrent use; the caller must serialize Suppress / Restore
+// calls and pair each Suppress with exactly one Restore.
 func SuppressMuPDFWarnings() {
-	C.suppress_mupdf_warnings()
+	suppressMuPDFWarnings()
 }
 
-// RestoreMuPDFWarnings restores MuPDF warnings output
+// RestoreMuPDFWarnings restores stderr to its original target. Safe to call
+// when no Suppress is active (no-op).
 func RestoreMuPDFWarnings() {
-	C.restore_mupdf_warnings()
+	restoreMuPDFWarnings()
 }
 
 // renderPageWithAnnotations renders a PDF page including all annotations and signature widgets

internal/pdf/render_suppress_posix.go

@@ -0,0 +1,37 @@
+//go:build (linux || darwin) && cgo
+
+package pdf
+
+/*
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+
+static int saved_stderr_fd = -1;
+
+void suppress_stderr(void) {
+    fflush(stderr);
+    if (saved_stderr_fd != -1) return;        // already suppressed
+    int devnull = open("/dev/null", O_WRONLY);
+    if (devnull == -1) return;
+    saved_stderr_fd = dup(2);                 // save original
+    if (saved_stderr_fd == -1) {
+        close(devnull);
+        return;
+    }
+    dup2(devnull, 2);
+    close(devnull);
+}
+
+void restore_stderr(void) {
+    fflush(stderr);
+    if (saved_stderr_fd == -1) return;        // nothing to restore
+    dup2(saved_stderr_fd, 2);
+    close(saved_stderr_fd);
+    saved_stderr_fd = -1;
+}
+*/
+import "C"
+
+func suppressMuPDFWarnings() { C.suppress_stderr() }
+func restoreMuPDFWarnings()  { C.restore_stderr() }