package api

import (
	"fmt"
	"regexp"

	"github.com/gin-gonic/gin"

	"immae.eu/Immae/Projets/Cryptomonnaies/Cryptoportfolio/Front/db"
)

const (
	VALID_EMAIL_REGEX = `(?i)^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$`
)

func IsValidEmailAddress(email string) bool {
	r := regexp.MustCompile(VALID_EMAIL_REGEX)

	return r.MatchString(email)
}

type SignParams struct {
	Email    string
	Password string
}

type SignResult struct {
	Token string `json:"token"`
}

func (s SignParams) Validate() *Error {
	if !IsValidEmailAddress(s.Email) {
		return &Error{InvalidEmail, "invalid email", fmt.Errorf("'%v' is not a valid email", s.Email)}
	}

	if s.Password == "" {
		return &Error{InvalidPassword, "invalid password", fmt.Errorf("invalid password")}
	}

	return nil
}

type SignupQuery struct {
	In SignParams
}

func (q SignupQuery) ValidateParams() *Error {
	return q.In.Validate()
}

func (q SignupQuery) Run() (interface{}, *Error) {
	user, err := db.GetUserByEmail(q.In.Email)
	if err != nil {
		return nil, NewInternalError(err)
	}

	if user != nil {
		return nil, &Error{EmailExists, "email already taken", fmt.Errorf("'%v' is already registered '%v'", q.In.Email, user)}
	}

	newUser := db.User{Email: q.In.Email, Status: db.AwaitingConfirmation}
	newUser.PasswordHash, err = db.HashPassword(q.In.Password)
	if err != nil {
		return nil, NewInternalError(err)
	}

	err = db.InsertUser(&newUser)
	if err != nil {
		return nil, NewInternalError(err)
	}

	token, err := CreateJwtToken(newUser.Id)
	if err != nil {
		return nil, NewInternalError(fmt.Errorf("cannot create jwt token %v", err))
	}

	return SignResult{token}, nil
}

type SigninQuery struct {
	In SignParams
}

func (q SigninQuery) ValidateParams() *Error {
	return q.In.Validate()
}

func (q SigninQuery) Run() (interface{}, *Error) {
	user, err := db.GetUserByEmail(q.In.Email)
	if err != nil {
		return nil, NewInternalError(err)
	}

	if user == nil {
		return nil, &Error{InvalidCredentials, "invalid credentials", fmt.Errorf("no email '%v' found", q.In.Email)}
	}

	err = db.ValidatePassword(q.In.Password, user.PasswordHash)
	if err != nil {
		return nil, &Error{InvalidCredentials, "invalid credentials", err}
	}

	if user.Status != db.Confirmed {
		return nil, &Error{UserNotConfirmed, "user awaiting admin validation", fmt.Errorf("user '%v' not confirmed", user)}
	}

	token, err := CreateJwtToken(user.Id)
	if err != nil {
		return nil, NewInternalError(err)
	}

	return SignResult{token}, nil
}

func UserConfirmed(c *gin.Context) *Error {
	user, exists := c.Get("user")

	if !exists {
		return &Error{NotAuthorized, "not authorized", fmt.Errorf("no user key in context")}
	}

	if user.(db.User).Status != db.Confirmed {
		return &Error{UserNotConfirmed, "user awaiting admin validation", fmt.Errorf("user '%v' not confirmed", user)}
	}

	return nil
}

func GetUser(c *gin.Context) db.User {
	user, _ := c.Get("user")

	return user.(db.User)
}