feat: add full tab completion to alternate readline lib

rl_readline-go.go

@@ -7,9 +7,11 @@ package main
 // this is hilbiline's, as is obvious by the filename
 
 import (
-	"io"
-	"strings"
 	"fmt"
+	"io"
+	"path/filepath"
+	"strings"
+	"os"
 
 	"github.com/maxlandon/readline"
 	"github.com/yuin/gopher-lua"
@@ -23,6 +25,172 @@ type lineReader struct {
 func newLineReader(prompt string) *lineReader {
 	rl := readline.NewInstance()
 	rl.Multiline = true
+	rl.TabCompleter = func(line []rune, pos int, _ readline.DelayedTabContext) (string, []*readline.CompletionGroup) {
+		ctx := string(line)
+		var completions []string
+		
+		compGroup := []*readline.CompletionGroup{
+			&readline.CompletionGroup{
+				TrimSlash: false,
+				NoSpace: true,
+			},
+		}
+
+		ctx = strings.TrimLeft(ctx, " ")
+		if len(ctx) == 0 {
+			return "", compGroup
+		}
+
+		fields := strings.Split(ctx, " ")
+		if len(fields) == 0 {
+			return "", compGroup
+		}
+		query := fields[len(fields) - 1]
+
+		ctx = aliases.Resolve(ctx)
+		
+		if len(fields) == 1 {
+			fileCompletions := fileComplete(query, ctx, fields)
+			if len(fileCompletions) != 0 {
+				for _, f := range fileCompletions {
+					name := strings.Replace(query + f, "~", curuser.HomeDir, 1)
+					if info, err := os.Stat(name); err == nil && info.Mode().Perm() & 0100 == 0 {
+						continue
+					}
+					completions = append(completions, f)
+				}
+				compGroup[0].Suggestions = completions
+				return "", compGroup
+			}
+			
+			// filter out executables, but in path
+			for _, dir := range filepath.SplitList(os.Getenv("PATH")) {
+				// print dir to stderr for debugging
+				// search for an executable which matches our query string
+				if matches, err := filepath.Glob(filepath.Join(dir, query + "*")); err == nil {
+					// get basename from matches
+					for _, match := range matches {
+						// check if we have execute permissions for our match
+						if info, err := os.Stat(match); err == nil && info.Mode().Perm() & 0100 == 0 {
+							continue
+						}
+						// get basename from match
+						name := filepath.Base(match)
+						// print name to stderr for debugging
+						// add basename to completions
+						completions = append(completions, name)
+					}
+				}
+			}
+			
+			// add lua registered commands to completions
+			for cmdName := range commands {
+				if strings.HasPrefix(cmdName, query) {
+					completions = append(completions, cmdName)
+				}
+			}
+			
+			compGroup[0].Suggestions = completions
+			return query, compGroup
+		} else {
+			if completecb, ok := luaCompletions["command." + fields[0]]; ok {
+				err := l.CallByParam(lua.P{
+					Fn: completecb,
+					NRet: 1,
+					Protect: true,
+				})
+
+				if err != nil {
+					return "", compGroup
+				}
+
+				luacompleteTable := l.Get(-1)
+				l.Pop(1)
+
+				if cmpTbl, ok := luacompleteTable.(*lua.LTable); ok {
+					cmpTbl.ForEach(func(key lua.LValue, value lua.LValue) {
+						// if key is a number (index), we just check and complete that
+						if key.Type() == lua.LTNumber {
+							// if we have only 2 fields then this is fine
+							if len(fields) == 2 {
+								if strings.HasPrefix(value.String(), fields[1]) {
+									completions = append(completions, value.String())
+								}
+							}
+						} else if key.Type() == lua.LTString {
+							if len(fields) == 2 {
+								if strings.HasPrefix(key.String(), fields[1]) {
+									completions = append(completions, key.String())
+								}
+							} else {
+								// if we have more than 2 fields, we need to check if the key matches
+								// the current field and if it does, we need to check if the value is a string
+								// or table (nested sub completions)
+								if key.String() == fields[1] {
+									// if value is a table, we need to iterate over it
+									// and add each value to completions
+									// check if value is either a table or function
+									if value.Type() == lua.LTTable {
+										valueTbl := value.(*lua.LTable)
+										valueTbl.ForEach(func(key lua.LValue, value lua.LValue) {
+											val := value.String()
+											if val == "<file>" {
+												// complete files
+												completions = append(completions, fileComplete(query, ctx, fields)...)
+											} else {
+												if strings.HasPrefix(val, query) {
+													completions = append(completions, val)
+												}
+											}
+										})
+									} else if value.Type() == lua.LTFunction {
+										// if value is a function, we need to call it
+										// and add each value to completions
+										// completionsCtx is the context we pass to the function,
+										// removing 2 fields from the fields array
+										completionsCtx := strings.Join(fields[2:], " ")
+										err := l.CallByParam(lua.P{
+											Fn: value,
+											NRet: 1,
+											Protect: true,
+										}, lua.LString(query), lua.LString(completionsCtx))
+
+										if err != nil {
+											return
+										}
+
+										luacompleteTable := l.Get(-1)
+										l.Pop(1)
+
+										// just check if its actually a table and add it to the completions
+										if cmpTbl, ok := luacompleteTable.(*lua.LTable); ok {
+											cmpTbl.ForEach(func(key lua.LValue, value lua.LValue) {
+												val := value.String()
+												if strings.HasPrefix(val, query) {
+													completions = append(completions, val)
+												}
+											})
+										}
+									} else {
+										// throw lua error
+										// complete.cmdname: error message...
+										l.RaiseError("complete." + fields[0] + ": completion value is not a table or function")
+									}
+								}
+							}
+						}
+					})
+				}
+			}
+
+			if len(completions) == 0 {
+				completions = fileComplete(query, ctx, fields)
+			}
+		}
+
+		compGroup[0].Suggestions = completions
+		return "", compGroup
+	}
 
 	return &lineReader{
 		rl,