feature (orgmode): use emacs to export org documents

server/ctrl/export.go

@@ -0,0 +1,149 @@
+package ctrl
+
+import (
+	"fmt"
+	. "github.com/mickael-kerjean/filestash/server/common"
+	"github.com/mickael-kerjean/filestash/server/model"
+	"github.com/gorilla/mux"
+	"io"
+	"net/http"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+)
+
+
+var EXPORT_PATH string
+func init() {
+	EXPORT_PATH = GetAbsolutePath(TMP_PATH)
+	os.RemoveAll(EXPORT_PATH)
+	os.MkdirAll(EXPORT_PATH, os.ModePerm)
+}
+func FileExport(ctx App, res http.ResponseWriter, req *http.Request) {
+	query := req.URL.Query()
+	p := mux.Vars(req)
+	mimeType := fmt.Sprintf("%s/%s", p["mtype0"], p["mtype1"])
+	path, err := pathBuilder(ctx, strings.Replace(req.URL.Path, fmt.Sprintf("/api/export/%s/%s/%s", p["share"], p["mtype0"], p["mtype1"]), "", 1))
+	if err != nil {
+		SendErrorResult(res, err)
+		return
+	} else if model.CanRead(&ctx) == false {
+		SendErrorResult(res, ErrPermissionDenied)
+		return
+	}
+	http.SetCookie(res, &http.Cookie{
+		Name:   "download",
+		Value:  "",
+		MaxAge: -1,
+		Path:   "/",
+	})
+
+	var tmpPath   string = EXPORT_PATH + "/export_" + QuickString(10)
+	var cmd       *exec.Cmd
+	var emacsPath string
+	var outPath   string
+	if GetMimeType(path) == "text/org" {
+		if emacsPath, err = exec.LookPath("emacs"); err != nil {
+			SendErrorResult(res, ErrMissingDependency)
+			return
+		}
+		if runtime.GOOS == "darwin" {
+			// on OSX, the default emacs isn't usable so we default to the one provided by `brew`
+			if f, err := os.OpenFile("/usr/local/Cellar/emacs/", os.O_RDONLY, os.ModePerm); err == nil {
+				if dirs, err := f.Readdirnames(0); err == nil {
+					if len(dirs) > 0 {
+						emacsPath = "/usr/local/Cellar/emacs/" + dirs[0] + "/bin/emacs"
+					}
+				}
+			}
+		}
+
+		if mimeType == "text/html" {
+			cmd = exec.Command(
+				emacsPath, "--no-init-file", "--batch",
+				"--load", GetAbsolutePath(CONFIG_PATH + "emacs.el"),
+				"--eval", "(setq org-html-extension \"org\")",
+				tmpPath + "/index.org", "-f", "org-html-export-to-html",
+			)
+			outPath = "index.org.org"
+		} else if mimeType == "application/pdf" {
+			cmd = exec.Command(
+				emacsPath, "--no-init-file", "--batch",
+				tmpPath + "/index.org", "-f", "org-latex-export-to-pdf",
+			)
+			if query.Get("mode") == "beamer" {
+				cmd = exec.Command(
+					emacsPath, "--no-init-file", "--batch",
+					tmpPath + "/index.org", "-f", "org-beamer-export-to-pdf",
+				)
+			}
+			outPath = "index.pdf"
+		} else if mimeType == "text/calendar" {
+			cmd = exec.Command(
+				emacsPath, "--no-init-file", "--batch",
+				tmpPath + "/index.org", "-f", "org-icalendar-export-to-ics",
+			)
+			outPath = "index.ics"
+		} else if mimeType == "text/plain" {
+			cmd = exec.Command(
+				emacsPath, "--no-init-file", "--batch",
+				tmpPath + "/index.org", "-f", "org-ascii-export-to-ascii",
+			)
+			outPath = "index.txt"
+		} else if mimeType == "text/x-latex" {
+			cmd = exec.Command(
+				emacsPath, "--no-init-file", "--batch",
+				tmpPath + "/index.org", "-f", "org-latex-export-to-latex",
+			)
+			outPath = "index.tex"
+		} else if mimeType == "text/markdown" {
+			cmd = exec.Command(
+				emacsPath, "--no-init-file", "--batch",
+				tmpPath + "/index.org", "-f", "org-md-export-to-markdown",
+			)
+			outPath = "index.md"
+		} else if mimeType == "application/vnd.oasis.opendocument.text" {
+			cmd = exec.Command(
+				emacsPath, "--no-init-file", "--batch",
+				tmpPath + "/index.org", "-f", "org-odt-export-to-odt",
+			)
+			outPath = "index.odt"
+		}else {
+			SendErrorResult(res, ErrNotImplemented)
+			return
+		}
+
+		os.MkdirAll(tmpPath, os.ModePerm)
+		defer os.RemoveAll(tmpPath)
+		f, err := os.OpenFile(tmpPath + "/index.org", os.O_WRONLY|os.O_CREATE, os.ModePerm)
+		if err != nil {
+			SendErrorResult(res, ErrFilesystemError)
+			return
+		}
+		file, err := ctx.Backend.Cat(path)
+		if err != nil {
+			SendErrorResult(res, err)
+			return
+		}
+		io.Copy(f, file)
+		// TODO: insert related resources: eg: images
+
+		if err = cmd.Run(); err != nil {
+			SendErrorResult(res, NewError("emacs has quit with error: '%s'" + err.Error(), 400))
+			return
+		}
+
+		f, err = os.OpenFile(tmpPath + "/"+outPath, os.O_RDONLY, os.ModePerm)
+		if err != nil {
+			SendErrorResult(res, ErrFilesystemError)
+			return
+		}
+		res.Header().Set("Content-Type", mimeType)
+		io.Copy(res, f)
+		return
+	}
+
+	SendErrorResult(res, ErrNotImplemented)
+	return
+}