package handlers

import (
	"errors"
	"time"

	"github.com/authelia/authelia/v4/internal/configuration/schema"
	"github.com/authelia/authelia/v4/internal/middlewares"
	"github.com/authelia/authelia/v4/internal/regulation"
	"github.com/authelia/authelia/v4/internal/utils"
)

// FirstFactorPOST is the handler performing the first factory.
//
//nolint:gocyclo // TODO: Consider refactoring time permitting.
func FirstFactorPOST(ctx *middlewares.AutheliaCtx) {
	bodyJSON := bodyFirstFactorRequest{}

	if err := ctx.ParseBody(&bodyJSON); err != nil {
		ctx.Logger.Errorf(logFmtErrParseRequestBody, regulation.AuthType1FA, err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	if bannedUntil, err := ctx.Providers.Regulator.Regulate(ctx, bodyJSON.Username); err != nil {
		if errors.Is(err, regulation.ErrUserIsBanned) {
			_ = markAuthenticationAttempt(ctx, false, &bannedUntil, bodyJSON.Username, regulation.AuthType1FA, nil)

			respondUnauthorized(ctx, messageAuthenticationFailed)

			return
		}

		ctx.Logger.Errorf(logFmtErrRegulationFail, regulation.AuthType1FA, bodyJSON.Username, err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	userPasswordOk, err := ctx.Providers.UserProvider.CheckUserPassword(bodyJSON.Username, bodyJSON.Password)
	if err != nil {
		_ = markAuthenticationAttempt(ctx, false, nil, bodyJSON.Username, regulation.AuthType1FA, err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	if !userPasswordOk {
		_ = markAuthenticationAttempt(ctx, false, nil, bodyJSON.Username, regulation.AuthType1FA, nil)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	if err = markAuthenticationAttempt(ctx, true, nil, bodyJSON.Username, regulation.AuthType1FA, nil); err != nil {
		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	// TODO: write tests.
	provider, err := ctx.GetSessionProvider()
	if err != nil {
		ctx.Logger.Errorf("%s", err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	userSession, err := provider.GetSession(ctx.RequestCtx)
	if err != nil {
		ctx.Logger.Errorf("%s", err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	newSession := provider.NewDefaultUserSession()

	// Reset all values from previous session except OIDC workflow before regenerating the cookie.
	if err = ctx.SaveSession(newSession); err != nil {
		ctx.Logger.Errorf(logFmtErrSessionReset, regulation.AuthType1FA, bodyJSON.Username, err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	if err = ctx.RegenerateSession(); err != nil {
		ctx.Logger.Errorf(logFmtErrSessionRegenerate, regulation.AuthType1FA, bodyJSON.Username, err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	// Check if bodyJSON.KeepMeLoggedIn can be deref'd and derive the value based on the configuration and JSON data.
	keepMeLoggedIn := !provider.Config.DisableRememberMe && bodyJSON.KeepMeLoggedIn != nil && *bodyJSON.KeepMeLoggedIn

	// Set the cookie to expire if remember me is enabled and the user has asked us to.
	if keepMeLoggedIn {
		err = provider.UpdateExpiration(ctx.RequestCtx, provider.Config.RememberMe)
		if err != nil {
			ctx.Logger.Errorf(logFmtErrSessionSave, "updated expiration", regulation.AuthType1FA, bodyJSON.Username, err)

			respondUnauthorized(ctx, messageAuthenticationFailed)

			return
		}
	}

	// Get the details of the given user from the user provider.
	userDetails, err := ctx.Providers.UserProvider.GetDetails(bodyJSON.Username)
	if err != nil {
		ctx.Logger.Errorf(logFmtErrObtainProfileDetails, regulation.AuthType1FA, bodyJSON.Username, err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	ctx.Logger.Tracef(logFmtTraceProfileDetails, bodyJSON.Username, userDetails.Groups, userDetails.Emails)

	userSession.SetOneFactor(ctx.Clock.Now(), userDetails, keepMeLoggedIn)

	if refresh, refreshInterval := getProfileRefreshSettings(ctx.Configuration.AuthenticationBackend); refresh {
		userSession.RefreshTTL = ctx.Clock.Now().Add(refreshInterval)
	}

	if err = ctx.SaveSession(userSession); err != nil {
		ctx.Logger.Errorf(logFmtErrSessionSave, "updated profile", regulation.AuthType1FA, bodyJSON.Username, err)

		respondUnauthorized(ctx, messageAuthenticationFailed)

		return
	}

	if bodyJSON.Workflow == workflowOpenIDConnect {
		handleOIDCWorkflowResponse(ctx, bodyJSON.TargetURL, bodyJSON.WorkflowID)
	} else {
		Handle1FAResponse(ctx, bodyJSON.TargetURL, bodyJSON.RequestMethod, userSession.Username, userSession.Groups)
	}
}

func getProfileRefreshSettings(cfg schema.AuthenticationBackend) (refresh bool, refreshInterval time.Duration) {
	if cfg.LDAP != nil {
		if cfg.RefreshInterval == schema.ProfileRefreshDisabled {
			refresh = false
			refreshInterval = 0
		} else {
			refresh = true

			if cfg.RefreshInterval != schema.ProfileRefreshAlways {
				refreshInterval, _ = utils.ParseDurationString(cfg.RefreshInterval)
			} else {
				refreshInterval = schema.RefreshIntervalAlways
			}
		}
	}

	return refresh, refreshInterval
}