lf/app.go
2021-05-19 21:55:19 +03:00

558 lines
11 KiB
Go

package main
import (
"bufio"
"fmt"
"io"
"log"
"os"
"os/exec"
"os/signal"
"path/filepath"
"strings"
"syscall"
"time"
)
type cmdItem struct {
prefix string
value string
}
type app struct {
ui *ui
nav *nav
ticker *time.Ticker
quitChan chan struct{}
cmd *exec.Cmd
cmdIn io.WriteCloser
cmdOutBuf []byte
cmdHistory []cmdItem
cmdHistoryBeg int
cmdHistoryInd int
}
func newApp(ui *ui, nav *nav) *app {
quitChan := make(chan struct{}, 1)
app := &app{
ui: ui,
nav: nav,
ticker: new(time.Ticker),
quitChan: quitChan,
}
sigChan := make(chan os.Signal, 1)
signal.Notify(sigChan, os.Interrupt, syscall.SIGHUP, syscall.SIGQUIT, syscall.SIGTERM)
go func() {
switch <-sigChan {
case os.Interrupt:
return
case syscall.SIGHUP, syscall.SIGQUIT, syscall.SIGTERM:
app.quit()
os.Exit(3)
return
}
}()
return app
}
func (app *app) quit() {
if err := app.writeHistory(); err != nil {
log.Printf("writing history file: %s", err)
}
if err := remote(fmt.Sprintf("drop %d", gClientID)); err != nil {
log.Printf("dropping connection: %s", err)
}
if gOpts.autoquit {
if err := remote("quit"); err != nil {
log.Printf("auto quitting server: %s", err)
}
}
os.Remove(gLogPath)
}
func (app *app) readFile(path string) {
log.Printf("reading file: %s", path)
f, err := os.Open(path)
if err != nil {
app.ui.echoerrf("opening file: %s", err)
return
}
defer f.Close()
p := newParser(f)
for p.parse() {
p.expr.eval(app, nil)
}
if p.err != nil {
app.ui.echoerrf("%s", p.err)
}
}
func loadFiles() (list []string, cp bool, err error) {
files, err := os.Open(gFilesPath)
if os.IsNotExist(err) {
err = nil
return
}
if err != nil {
err = fmt.Errorf("opening file selections file: %s", err)
return
}
defer files.Close()
s := bufio.NewScanner(files)
s.Scan()
switch s.Text() {
case "copy":
cp = true
case "move":
cp = false
default:
err = fmt.Errorf("unexpected option to copy file(s): %s", s.Text())
return
}
for s.Scan() && s.Text() != "" {
list = append(list, s.Text())
}
if s.Err() != nil {
err = fmt.Errorf("scanning file list: %s", s.Err())
return
}
log.Printf("loading files: %v", list)
return
}
func saveFiles(list []string, cp bool) error {
files, err := os.Create(gFilesPath)
if err != nil {
return fmt.Errorf("opening file selections file: %s", err)
}
defer files.Close()
log.Printf("saving files: %v", list)
if cp {
fmt.Fprintln(files, "copy")
} else {
fmt.Fprintln(files, "move")
}
for _, f := range list {
fmt.Fprintln(files, f)
}
return nil
}
func (app *app) readHistory() error {
f, err := os.Open(gHistoryPath)
if os.IsNotExist(err) {
return nil
}
if err != nil {
return fmt.Errorf("opening history file: %s", err)
}
defer f.Close()
scanner := bufio.NewScanner(f)
for scanner.Scan() {
toks := strings.SplitN(scanner.Text(), " ", 2)
if toks[0] != ":" && toks[0] != "$" && toks[0] != "%" && toks[0] != "!" && toks[0] != "&" {
continue
}
if len(toks) < 2 {
continue
}
app.cmdHistory = append(app.cmdHistory, cmdItem{toks[0], toks[1]})
}
app.cmdHistoryBeg = len(app.cmdHistory)
if err := scanner.Err(); err != nil {
return fmt.Errorf("reading history file: %s", err)
}
return nil
}
func (app *app) writeHistory() error {
if len(app.cmdHistory) == 0 {
return nil
}
local := make([]cmdItem, len(app.cmdHistory)-app.cmdHistoryBeg)
copy(local, app.cmdHistory[app.cmdHistoryBeg:])
app.cmdHistory = nil
if err := app.readHistory(); err != nil {
return fmt.Errorf("reading history file: %s", err)
}
app.cmdHistory = append(app.cmdHistory, local...)
if err := os.MkdirAll(filepath.Dir(gHistoryPath), os.ModePerm); err != nil {
return fmt.Errorf("creating data directory: %s", err)
}
f, err := os.Create(gHistoryPath)
if err != nil {
return fmt.Errorf("creating history file: %s", err)
}
defer f.Close()
if len(app.cmdHistory) > 1000 {
app.cmdHistory = app.cmdHistory[len(app.cmdHistory)-1000:]
}
for _, cmd := range app.cmdHistory {
_, err = f.WriteString(fmt.Sprintf("%s %s\n", cmd.prefix, cmd.value))
if err != nil {
return fmt.Errorf("writing history file: %s", err)
}
}
return nil
}
// This is the main event loop of the application. Expressions are read from
// the client and the server on separate goroutines and sent here over channels
// for evaluation. Similarly directories and regular files are also read in
// separate goroutines and sent here for update.
func (app *app) loop() {
go app.nav.previewLoop(app.ui)
serverChan := readExpr()
app.ui.readExpr()
if gSelect != "" {
go func() {
lstat, err := os.Lstat(gSelect)
if err != nil {
app.ui.exprChan <- &callExpr{"echoerr", []string{err.Error()}, 1}
} else if lstat.IsDir() {
app.ui.exprChan <- &callExpr{"cd", []string{gSelect}, 1}
} else {
app.ui.exprChan <- &callExpr{"select", []string{gSelect}, 1}
}
}()
}
if gConfigPath != "" {
if _, err := os.Stat(gConfigPath); !os.IsNotExist(err) {
app.readFile(gConfigPath)
} else {
log.Printf("config file does not exist: %s", err)
}
} else {
for _, path := range gConfigPaths {
if _, err := os.Stat(path); !os.IsNotExist(err) {
app.readFile(path)
}
}
}
for _, cmd := range gCommands {
p := newParser(strings.NewReader(cmd))
for p.parse() {
p.expr.eval(app, nil)
}
if p.err != nil {
app.ui.echoerrf("%s", p.err)
}
}
for {
select {
case <-app.quitChan:
if app.nav.copyTotal > 0 {
app.ui.echoerr("quit: copy operation in progress")
continue
}
if app.nav.moveTotal > 0 {
app.ui.echoerr("quit: move operation in progress")
continue
}
if app.nav.deleteTotal > 0 {
app.ui.echoerr("quit: delete operation in progress")
continue
}
app.quit()
app.nav.previewChan <- ""
log.Print("bye!")
if gLastDirPath != "" {
f, err := os.Create(gLastDirPath)
if err != nil {
log.Printf("opening last dir file: %s", err)
}
defer f.Close()
_, err = f.WriteString(app.nav.currDir().path)
if err != nil {
log.Printf("writing last dir file: %s", err)
}
}
return
case n := <-app.nav.copyBytesChan:
app.nav.copyBytes += n
// n is usually 4096B so update roughly per 4096B x 1024 = 4MB copied
if app.nav.copyUpdate++; app.nav.copyUpdate >= 1024 {
app.nav.copyUpdate = 0
app.ui.draw(app.nav)
}
case n := <-app.nav.copyTotalChan:
app.nav.copyTotal += n
if n < 0 {
app.nav.copyBytes += n
}
if app.nav.copyTotal == 0 {
app.nav.copyUpdate = 0
}
app.ui.draw(app.nav)
case n := <-app.nav.moveCountChan:
app.nav.moveCount += n
if app.nav.moveUpdate++; app.nav.moveUpdate >= 1000 {
app.nav.moveUpdate = 0
app.ui.draw(app.nav)
}
case n := <-app.nav.moveTotalChan:
app.nav.moveTotal += n
if n < 0 {
app.nav.moveCount += n
}
if app.nav.moveTotal == 0 {
app.nav.moveUpdate = 0
}
app.ui.draw(app.nav)
case n := <-app.nav.deleteCountChan:
app.nav.deleteCount += n
if app.nav.deleteUpdate++; app.nav.deleteUpdate >= 1000 {
app.nav.deleteUpdate = 0
app.ui.draw(app.nav)
}
case n := <-app.nav.deleteTotalChan:
app.nav.deleteTotal += n
if n < 0 {
app.nav.deleteCount += n
}
if app.nav.deleteTotal == 0 {
app.nav.deleteUpdate = 0
}
app.ui.draw(app.nav)
case d := <-app.nav.dirChan:
app.nav.checkDir(d)
prev, ok := app.nav.dirCache[d.path]
if ok {
d.ind = prev.ind
d.sel(prev.name(), app.nav.height)
}
app.nav.dirCache[d.path] = d
for i := range app.nav.dirs {
if app.nav.dirs[i].path == d.path {
app.nav.dirs[i] = d
}
}
app.nav.position()
curr, err := app.nav.currFile()
if err == nil {
if d.path == app.nav.currDir().path {
app.ui.loadFile(app.nav, true)
}
if d.path == curr.path {
app.ui.dirPrev = d
}
}
app.ui.draw(app.nav)
case r := <-app.nav.regChan:
app.nav.checkReg(r)
app.nav.regCache[r.path] = r
curr, err := app.nav.currFile()
if err == nil {
if r.path == curr.path {
app.ui.regPrev = r
}
}
app.ui.draw(app.nav)
case ev := <-app.ui.evChan:
e := app.ui.readEvent(ev)
if e == nil {
continue
}
e.eval(app, nil)
loop:
for {
select {
case ev := <-app.ui.evChan:
e = app.ui.readEvent(ev)
if e == nil {
continue
}
e.eval(app, nil)
default:
break loop
}
}
app.ui.draw(app.nav)
case e := <-app.ui.exprChan:
e.eval(app, nil)
app.ui.draw(app.nav)
case e := <-serverChan:
e.eval(app, nil)
app.ui.draw(app.nav)
case <-app.ticker.C:
app.nav.renew()
app.ui.loadFile(app.nav, false)
app.ui.draw(app.nav)
}
}
}
func (app *app) exportFiles() {
var currFile string
if curr, err := app.nav.currFile(); err == nil {
currFile = curr.path
}
currSelections := app.nav.currSelections()
exportFiles(currFile, currSelections, app.nav.currDir().path)
}
// This function is used to run a shell command. Modes are as follows:
//
// Prefix Wait Async Stdin Stdout Stderr UI action
// $ No No Yes Yes Yes Pause and then resume
// % No No Yes Yes Yes Statline for input/output
// ! Yes No Yes Yes Yes Pause and then resume
// & No Yes No No No Do nothing
func (app *app) runShell(s string, args []string, prefix string) {
app.exportFiles()
exportOpts()
cmd := shellCommand(s, args)
var out io.Reader
var err error
switch prefix {
case "$", "!":
cmd.Stdin = os.Stdin
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
app.nav.previewChan <- ""
if err := app.ui.suspend(); err != nil {
log.Printf("suspend: %s", err)
}
defer func() {
if err := app.ui.resume(); err != nil {
app.quit()
os.Exit(3)
return
}
}()
defer app.nav.renew()
err = cmd.Run()
case "%":
stdin, err := cmd.StdinPipe()
if err != nil {
log.Printf("writing stdin: %s", err)
}
app.cmdIn = stdin
stdout, err := cmd.StdoutPipe()
if err != nil {
log.Printf("reading stdout: %s", err)
}
out = stdout
cmd.Stderr = cmd.Stdout
fallthrough
case "&":
err = cmd.Start()
}
if err != nil {
app.ui.echoerrf("running shell: %s", err)
}
switch prefix {
case "!":
anyKey()
}
app.ui.loadFile(app.nav, true)
switch prefix {
case "%":
app.cmd = cmd
app.cmdOutBuf = nil
app.ui.msg = ""
app.ui.cmdPrefix = ">"
go func() {
eol := false
reader := bufio.NewReader(out)
for {
b, err := reader.ReadByte()
if err == io.EOF {
break
}
if eol {
eol = false
app.cmdOutBuf = nil
}
app.cmdOutBuf = append(app.cmdOutBuf, b)
if b == '\n' || b == '\r' {
eol = true
}
if reader.Buffered() > 0 {
continue
}
app.ui.exprChan <- &callExpr{"echo", []string{string(app.cmdOutBuf)}, 1}
}
if err := cmd.Wait(); err != nil {
log.Printf("running shell: %s", err)
}
app.cmd = nil
app.ui.cmdPrefix = ""
app.ui.exprChan <- &callExpr{"load", nil, 1}
}()
case "&":
go func() {
if err := cmd.Wait(); err != nil {
log.Printf("running shell: %s", err)
}
}()
}
}