package repl

import (
	"context"
	"fmt"
	"github.com/lmika/gopkgs/fp/maps"
	"sort"
	"ucl.lmika.dev/ucl"
)

type CommandOpt interface {
	config(cmdName string, r *REPL)
}

type REPL struct {
	inst *ucl.Inst

	commandDocs map[string]Doc
}

func New(opts ...ucl.InstOption) *REPL {
	inst := ucl.New(opts...)

	r := &REPL{
		inst:        inst,
		commandDocs: make(map[string]Doc),
	}
	inst.SetBuiltin("help", r.helpBuiltin)

	return r
}

func (r *REPL) Inst() *ucl.Inst {
	return r.inst
}

func (r *REPL) SetCommand(name string, fn ucl.BuiltinHandler, opts ...CommandOpt) {
	r.commandDocs[name] = Doc{}
	for _, opt := range opts {
		opt.config(name, r)
	}

	r.inst.SetBuiltin(name, fn)
}

func (r *REPL) helpBuiltin(ctx context.Context, args ucl.CallArgs) (any, error) {
	switch {
	case args.NArgs() == 0:
		// TEMP
		names := maps.Keys(r.commandDocs)
		sort.Strings(names)

		for _, name := range names {
			cdoc := r.commandDocs[name]
			if cdoc.Brief != "" {
				fmt.Println("%v\t%v", name, r.commandDocs[name])
			} else {
				fmt.Println("%v", name)
			}
		}
		// END TEMP
	}
	return nil, nil
}