fzf/src/history.go
2023-07-16 17:14:22 +09:00

96 lines
2.0 KiB
Go

package fzf
import (
"errors"
"os"
"strings"
)
// History struct represents input history
type History struct {
path string
lines []string
modified map[int]string
maxSize int
cursor int
}
// NewHistory returns the pointer to a new History struct
func NewHistory(path string, maxSize int) (*History, error) {
fmtError := func(e error) error {
if os.IsPermission(e) {
return errors.New("permission denied: " + path)
}
return errors.New("invalid history file: " + e.Error())
}
// Read history file
data, err := os.ReadFile(path)
if err != nil {
// If it doesn't exist, check if we can create a file with the name
if os.IsNotExist(err) {
data = []byte{}
if err := os.WriteFile(path, data, 0600); err != nil {
return nil, fmtError(err)
}
} else {
return nil, fmtError(err)
}
}
// Split lines and limit the maximum number of lines
lines := strings.Split(strings.Trim(string(data), "\n"), "\n")
if len(lines[len(lines)-1]) > 0 {
lines = append(lines, "")
}
return &History{
path: path,
maxSize: maxSize,
lines: lines,
modified: make(map[int]string),
cursor: len(lines) - 1}, nil
}
func (h *History) append(line string) error {
// We don't append empty lines
if len(line) == 0 {
return nil
}
lines := append(h.lines[:len(h.lines)-1], line)
if len(lines) > h.maxSize {
lines = lines[len(lines)-h.maxSize:]
}
h.lines = append(lines, "")
return os.WriteFile(h.path, []byte(strings.Join(h.lines, "\n")), 0600)
}
func (h *History) override(str string) {
// You can update the history, but they're not written to the file
if h.cursor == len(h.lines)-1 {
h.lines[h.cursor] = str
} else if h.cursor < len(h.lines)-1 {
h.modified[h.cursor] = str
}
}
func (h *History) current() string {
if str, prs := h.modified[h.cursor]; prs {
return str
}
return h.lines[h.cursor]
}
func (h *History) previous() string {
if h.cursor > 0 {
h.cursor--
}
return h.current()
}
func (h *History) next() string {
if h.cursor < len(h.lines)-1 {
h.cursor++
}
return h.current()
}