package useCases

import (
	"RenewCMS/internal/domain/article"
	"RenewCMS/internal/domain/audit"
	"RenewCMS/internal/domain/author"
	"RenewCMS/internal/domain/image"
	"RenewCMS/internal/domain/invite"
	"RenewCMS/internal/domain/purge"
	"RenewCMS/internal/domain/site"
	"RenewCMS/internal/domain/update"
	"RenewCMS/internal/domain/user"
	"context"
	"errors"
	"slices"
)

const GenericFailureReason = "Something went wrong on our side. Please try again."

type failureReason struct {
	cause  error
	reason string
}

var failureReasons = []failureReason{
	{article.ErrInvalidTitle, "The title must be between 3 and 200 characters."},
	{image.ErrImageTypeNotAllowed, "The file must be a PNG, JPEG, WEBP or SVG image."},
	{image.ErrImageTooLarge, "The file is too large to upload."},
	{image.ErrImageUnreadable, "The image could not be read."},
	{image.ErrInvalidFilename, "That file name is not valid."},
	{image.ErrInvalidMergeRequest, "The merge request is not valid."},
	{image.ErrMergeCopyMissing, "One of the copies no longer exists."},
	{image.ErrMergeHashMismatch, "The images are not identical copies."},
	{image.ErrSourceTooLarge, "The source image is too large to generate this variant."},
	{image.ErrVariantSourceUnsupported, "Variants aren't generated for this format."},
	{image.ErrVariantSourceUnreadable, "The source image can't be read, so this variant can't be generated."},
	{image.ErrVariantExists, "A variant with that name already exists."},
	{purge.ErrPurgeConflict, "The library changed since the preview. Review it again."},
	{purge.ErrPurgeBusy, "A purge is already running."},
	{user.ErrRegistrationClosed, "Registration is closed on this site."},
	{user.ErrVerificationEmailNotSent, "The verification email could not be sent."},
	{user.ErrInvalidVerificationCode, "The verification code is not valid."},
	{user.ErrVerificationCodeExpired, "The verification code has expired."},
	{user.ErrInvalidDisplayName, "That display name is too long."},
	{user.ErrUsernameTaken, "That username is already taken."},
	{invite.ErrEmailHasAccount, "That email already has an account."},
	{invite.ErrPendingInvite, "An invitation is already pending for that email."},
	{invite.ErrInviteEmailNotSent, "The invitation email could not be sent."},
	{invite.ErrInviteAlreadyAccepted, "That invitation was already accepted."},
	{invite.ErrInviteInvalid, "That invitation is not valid."},
	{invite.ErrInviteExpired, "That invitation has expired."},
	{update.ErrFeedUnavailable, "The release feed could not be reached."},
	{update.ErrNoRelease, "No release was found."},
	{update.ErrNotPrepared, "This server cannot apply updates."},
	{update.ErrJobInProgress, "An update is already being downloaded."},
	{update.ErrRestartPending, "A restart is already pending."},
	{update.ErrNothingToUpdate, "There is nothing to update."},
	{update.ErrPreflightRefused, "The update cannot be downloaded."},
	{update.ErrRestartKindMismatch, "The requested restart does not match the server state."},
	{site.ErrSiteKeyTaken, "A site with that key already exists."},
	{site.ErrKeyImmutable, "The key of a site cannot be changed."},
	{site.ErrDefaultSite, "The default site cannot be deleted."},
	{site.ErrSiteHasArticles, "The site still has articles."},
	{site.ErrInvalidSiteURL, "The site address is not valid."},
	{site.ErrInvalidLocale, "The locale is not valid."},
	{site.ErrUseSetDefault, "Use the default site action to change the default."},
	{site.ErrInvalidReassign, "The destination site is not valid."},
	{author.ErrSlugTaken, "That slug is already used by another author."},
	{author.ErrUserAlreadyLinked, "That user already has an author."},
	{author.ErrAuthorAlreadyLinked, "That author is already linked to a user."},
	{author.ErrAuthorRights, "Only an owner or admin can change this author."},
	{author.ErrAuthorHasArticles, "The author is still credited on articles."},
	{author.ErrInvalidReassign, "The destination author is not valid."},
}

var restartFailureReasons = []failureReason{
	{update.ErrJobInProgress, "An update is still being downloaded."},
}

var downloadFailureReasons = map[string]string{
	update.ErrorKindDownload:     "The update could not be downloaded.",
	update.ErrorKindVerification: "The downloaded update failed its integrity check.",
}

var notFoundCauses = []error{
	article.ErrArticleNotFound,
	image.ErrImageNotFound,
	image.ErrVariantNotFound,
	invite.ErrInviteNotFound,
	user.ErrUserNotFound,
	site.ErrSiteNotFound,
	author.ErrAuthorNotFound,
	author.ErrBioTooLong,
	author.ErrInvalidURL,
	author.ErrTooManyLinks,
	author.ErrInvalidSlug,
}

func reasonFor(err error, overrides ...failureReason) string {
	for _, candidate := range slices.Concat(overrides, failureReasons) {
		if errors.Is(err, candidate.cause) {
			return candidate.reason
		}
	}
	return GenericFailureReason
}

func isNotFound(err error) bool {
	for _, cause := range notFoundCauses {
		if errors.Is(err, cause) {
			return true
		}
	}
	return false
}

func recordFailure(ctx context.Context, recorder audit.Recorder, event audit.Event, err error, overrides ...failureReason) {
	if isNotFound(err) {
		return
	}
	failFrom(ctx, recorder, event, reasonFor(err, overrides...))
}

func failFrom(ctx context.Context, recorder audit.Recorder, event audit.Event, reason string) {
	event.Outcome = audit.OutcomeFailed
	event.FailureReason = &reason
	recorder.Record(ctx, event)
}