package eval

import (
	"context"
	"encoding/json"
	"fmt"

	"github.com/MontFerret/ferret/pkg/runtime/core"
	"github.com/MontFerret/ferret/pkg/runtime/values"
	"github.com/mafredri/cdp"
	"github.com/mafredri/cdp/protocol/runtime"
)

func PrepareEval(exp string) string {
	return fmt.Sprintf("((function () {%s})())", exp)
}

func Eval(ctx context.Context, client *cdp.Client, exp string, ret bool, async bool) (core.Value, error) {
	args := runtime.
		NewEvaluateArgs(PrepareEval(exp)).
		SetReturnByValue(ret).
		SetAwaitPromise(async)

	out, err := client.Runtime.Evaluate(ctx, args)

	if err != nil {
		return values.None, err
	}

	if out.ExceptionDetails != nil {
		ex := out.ExceptionDetails

		return values.None, core.Error(
			core.ErrUnexpected,
			fmt.Sprintf("%s: %s", ex.Text, *ex.Exception.Description),
		)
	}

	if out.Result.Type != "undefined" {
		return values.Unmarshal(out.Result.Value)
	}

	return Unmarshal(&out.Result)
}

func Property(
	ctx context.Context,
	client *cdp.Client,
	objectID runtime.RemoteObjectID,
	propName string,
) (core.Value, error) {
	res, err := client.Runtime.GetProperties(
		ctx,
		runtime.NewGetPropertiesArgs(objectID),
	)

	if err != nil {
		return values.None, err
	}

	if res.ExceptionDetails != nil {
		return values.None, res.ExceptionDetails
	}

	// all props
	if propName == "" {
		var arr *values.Array
		arr = values.NewArray(len(res.Result))

		for _, prop := range res.Result {
			val, err := Unmarshal(prop.Value)

			if err != nil {
				return values.None, err
			}

			arr.Push(val)
		}

		return arr, nil
	}

	for _, prop := range res.Result {
		if prop.Name == propName {
			return Unmarshal(prop.Value)
		}
	}

	return values.None, nil
}

func Method(
	ctx context.Context,
	client *cdp.Client,
	objectID runtime.RemoteObjectID,
	methodName string,
	args []runtime.CallArgument,
) (*runtime.RemoteObject, error) {
	found, err := client.Runtime.CallFunctionOn(
		ctx,
		runtime.NewCallFunctionOnArgs(methodName).
			SetObjectID(objectID).
			SetArguments(args),
	)

	if err != nil {
		return nil, err
	}

	if found.ExceptionDetails != nil {
		return nil, found.ExceptionDetails
	}

	if found.Result.ObjectID == nil {
		return nil, nil
	}

	return &found.Result, nil
}

func MethodQuerySelector(
	ctx context.Context,
	client *cdp.Client,
	objectID runtime.RemoteObjectID,
	selector string,
) (runtime.RemoteObjectID, error) {
	bytes, err := json.Marshal(selector)

	if err != nil {
		return "", err
	}

	obj, err := Method(ctx, client, objectID, "querySelector", []runtime.CallArgument{
		{
			Value: json.RawMessage(bytes),
		},
	})

	if err != nil {
		return "", err
	}

	if obj.ObjectID == nil {
		return "", nil
	}

	return *obj.ObjectID, nil
}

func Unmarshal(obj *runtime.RemoteObject) (core.Value, error) {
	if obj == nil {
		return values.None, nil
	}

	if obj.Type != "undefined" {
		return values.Unmarshal(obj.Value)
	}

	return values.None, nil
}