package app

import (
	"context"
	"fmt"

	"emperror.dev/errors"
	"git.sleepycat.moe/sam/mercury/internal/database"
	"github.com/golang-jwt/jwt/v4"
)

func (app *App) TokenToJWT(token database.Token) (string, error) {
	t := jwt.NewWithClaims(jwt.SigningMethodHS256, token.ToClaims())

	return t.SignedString(app.tokenKey)
}

func (app *App) ParseToken(ctx context.Context, token string) (t database.Token, err error) {
	parsed, err := jwt.ParseWithClaims(token, &database.TokenClaims{}, func(t *jwt.Token) (interface{}, error) {
		if _, ok := t.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf(`unexpected signing method "%v"`, t.Header["alg"])
		}

		return app.tokenKey, nil
	})

	if err != nil {
		return t, errors.Wrap(err, "parsing token")
	}

	c, ok := parsed.Claims.(*database.TokenClaims)
	if !ok || !parsed.Valid {
		return t, fmt.Errorf("unknown claims type %T", parsed.Claims)
	}

	t, err = app.Token().Get(ctx, c.TokenID)
	if err != nil {
		return t, errors.Wrap(err, "getting token from database")
	}
	return t, nil
}