package scpt

import (
	"errors"
	"fmt"
	"github.com/alecthomas/participle"
	"github.com/gen2brain/dlgs"
	"io"
	"os"
	"os/exec"
	"reflect"
	"strings"
)

var Vars = map[string]interface{}{}

type FuncMap map[string]func(map[string]interface{}) (interface{}, error)

var Funcs = FuncMap{
	"displaydialog": displayDialog,
	"doshellscript": doShellScript,
}

func AddFuncs(fnMap FuncMap) {
	for name, fn := range fnMap {
		Funcs[name] = fn
	}
}

func AddVars(varMap map[string]interface{}) {
	for name, val := range varMap {
		Vars[name] = val
	}
}

func Parse(r io.Reader) (*AST, error) {
	parser, err := participle.Build(&AST{})
	if err != nil {
		return nil, err
	}
	ast := &AST{}
	err = parser.Parse("", r, ast)
	if err != nil {
		return nil, err
	}
	return ast, nil
}

func Execute(ast AST) {
	for _, cmd := range ast.Commands {
		if cmd.Vars != nil {
			for _, Var := range cmd.Vars {
				val := ParseValue(Var.Value)
				if strings.Contains(reflect.TypeOf(val).String(), ".FuncCall") {
					Call := val.(*FuncCall)
					Vars[Var.Key], _ = CallFunction(Call)
				} else {
					Vars[Var.Key] = val
				}
			}
		} else if cmd.Calls != nil {
			for _, Call := range cmd.Calls {
				_, _ = CallFunction(Call)
			}
		}
	}
}

func ParseValue(val *Value) interface{} {
	if val.String != nil {
		return strings.Trim(*val.String, `"`)
	} else if val.Bool != nil {
		return *val.Bool
	} else if val.Float != nil {
		return *val.Float
	} else if val.Integer != nil {
		return *val.Integer
	} else if val.SubCmd != nil {
		return val.SubCmd
	} else if val.VarVal != nil {
		return Vars[*val.VarVal]
	}
	return nil
}

func UnwrapArgs(args []*Arg) map[string]interface{} {
	argMap := map[string]interface{}{}
	for _, arg := range args {
		argMap[arg.Key] = ParseValue(arg.Value)
	}
	return argMap
}

func CallFunction(call *FuncCall) (interface{}, error) {
	argMap := UnwrapArgs(call.Args)
	return Funcs[call.Name](argMap)
}

func displayDialog(args map[string]interface{}) (interface{}, error) {
	title, ok := args["title"]
	if !ok {
		return nil, errors.New("title not provided")
	}
	text, ok := args["text"]
	if !ok {
		return nil, errors.New("text not provided")
	}
	switch args["type"] {
	case "yesno":
		return dlgs.Question(fmt.Sprint(title), fmt.Sprint(text), true)
	case "info":
		return dlgs.Info(fmt.Sprint(title), fmt.Sprint(text))
	case "error":
		return dlgs.Error(fmt.Sprint(title), fmt.Sprint(text))
	case "entry":
		defaultText, ok := args["default"]
		if !ok {
			defaultText = ""
		}
		input, _, err := dlgs.Entry(fmt.Sprint(title), fmt.Sprint(text), fmt.Sprint(defaultText))
		return input, err
	}
	return nil, nil
}

func doShellScript(args map[string]interface{}) (interface{}, error) {
	script, ok := args["content"].(string)
	if ok {
		cmd := exec.Command("sh", "-c", script)
		cmd.Stdout = os.Stdout
		_ = cmd.Run()
		return "", nil
	} else {
		return nil, errors.New("script not provided")
	}
}