package utils

import (
	"gosh/types"
	"os"
	"strings"
)

type AutoCompleter struct {
	Sh *types.Shell
}

func (a *AutoCompleter) Do(line []rune, pos int) ([][]rune, int) {
	cmds := []string{"ls", "cd", "pwd", "cat", "grep", "clear", "apath", "exit"}
	potential_suggestions := []string{}

	s_line := string(line)
	words := strings.Fields(s_line)

	last_word := ""
	if len(words) > 0 {
		last_word = words[len(words)-1]
	}

	// If typing the command (first word), suggest commands
	if len(words) == 0 || (len(words) == 1 && s_line[len(s_line)-1] != ' ') {
		potential_suggestions = append(potential_suggestions, cmds...)
	} else if words[0] == "cd" || words[0] == "ls" {
		// Suggest directories for 'cd'
		last_word := ""
		if len(words) > 1 {
			last_word = words[len(words)-1]
		}
		children, err := os.ReadDir(a.Sh.Cd)
		if err == nil {
			for _, child := range children {
				if child.IsDir() && (last_word == "" || strings.HasPrefix(child.Name(), last_word)) {
					potential_suggestions = append(potential_suggestions, child.Name())
				}
			}
		}
	} else if words[0] == "cat" {
		// Suggest directories for 'cat'
		last_word := ""
		if len(words) > 1 {
			last_word = words[len(words)-1]
		}
		children, err := os.ReadDir(a.Sh.Cd)
		if err == nil {
			for _, child := range children {
				if !child.IsDir() && (last_word == "" || strings.HasPrefix(child.Name(), last_word)) {
					potential_suggestions = append(potential_suggestions, child.Name())
				}
			}
		}
	}

	var suggestions [][]rune
	for _, s := range potential_suggestions {
		// Only append the part that should be completed (remove the prefix)
		if last_word != "" && strings.HasPrefix(s, last_word) {
			suggestions = append(suggestions, []rune(s[len(last_word):]))
		} else {
			suggestions = append(suggestions, []rune(s))
		}
	}

	return suggestions, len([]rune(s_line))
}