package invitationimp

import (
	"context"
	"encoding/json"
	"errors"
	"net/http"

	"github.com/tech/sendico/pkg/api/http/response"
	"github.com/tech/sendico/pkg/merrors"
	an "github.com/tech/sendico/pkg/messaging/notifications/account"
	"github.com/tech/sendico/pkg/model"
	"github.com/tech/sendico/pkg/mutil/mzap"
	"github.com/tech/sendico/server/interface/api/srequest"
	"go.mongodb.org/mongo-driver/v2/bson"
	"go.uber.org/zap"
)

func (a *InvitationAPI) doAccept(ctx context.Context, invitationRef bson.ObjectID, accData *model.AccountData) error {
	inv, err := a.getPendingInvitation(ctx, invitationRef)
	if err != nil {
		return err
	}

	org, err := a.getOrganization(ctx, inv.OrganizationRef, inv.Content.Email)
	if err != nil {
		return err
	}

	if _, err := a.fetchOrCreateAccount(ctx, org, inv, accData); err != nil {
		return err
	}

	if err := a.db.Accept(ctx, invitationRef); err != nil {
		a.Logger.Warn("Failed to accept invitation", zap.Error(err), mzap.ObjRef("invitation_ref", invitationRef))
		return err
	}

	return nil
}

func (a *InvitationAPI) sendWelcomeEmail(account *model.Account, token string) error {
	if err := a.producer.SendMessage(an.AccountCreated(a.Name(), *account.GetID(), token)); err != nil {
		a.Logger.Warn("Failed to send account creation notification", zap.Error(err))
		return err
	}
	return nil
}

func (a *InvitationAPI) getPendingInvitation(ctx context.Context, invitationRef bson.ObjectID) (*model.Invitation, error) {
	a.Logger.Debug("Fetching invitation", mzap.ObjRef("invitation_ref", invitationRef))
	var inv model.Invitation
	if err := a.db.Unprotected().Get(ctx, invitationRef, &inv); err != nil {
		a.Logger.Warn("Failed to fetch invitation", zap.Error(err), mzap.ObjRef("invitation_ref", invitationRef))
		return nil, err
	}
	if inv.Status != model.InvitationCreated {
		a.Logger.Warn("Invitation is not pending", mzap.StorableRef(&inv))
		return nil, merrors.InvalidArgument("Invitation is not pending")
	}
	return &inv, nil
}

func (a *InvitationAPI) getOrganization(ctx context.Context, orgRef bson.ObjectID, email string) (*model.Organization, error) {
	a.Logger.Debug("Fetching organization", mzap.ObjRef("organization_ref", orgRef), zap.String("email", email))
	var org model.Organization
	if err := a.odb.Unprotected().Get(ctx, orgRef, &org); err != nil {
		a.Logger.Warn("Failed to fetch organization when processing invitation", zap.Error(err),
			mzap.ObjRef("organization_ref", orgRef), zap.String("email", email))
		return nil, err
	}
	return &org, nil
}

func (a *InvitationAPI) fetchOrCreateAccount(ctx context.Context, org *model.Organization, inv *model.Invitation, accData *model.AccountData) (*model.Account, error) {
	account, err := a.adb.GetByEmail(ctx, inv.Content.Email)
	if errors.Is(err, merrors.ErrNoData) {
		a.Logger.Debug("Account is not registered, creating", zap.String("email", inv.Content.Email))
		if accData == nil {
			a.Logger.Warn("Account data missing for unregistered invitation acceptance",
				zap.String("email", inv.Content.Email), mzap.StorableRef(inv))
			return nil, merrors.InvalidArgument("No account data provided for invitation acceptance")
		}

		account = accData.ToAccount()
		if err := a.accService.ValidateAccount(account); err != nil {
			a.Logger.Info("Account validation failed", zap.Error(err), zap.String("email", inv.Content.Email))
			return nil, err
		}
		// creates account and joins organization
		token, err := a.accService.CreateAccount(ctx, org, account, inv.RoleRef)
		if err != nil {
			a.Logger.Warn("Failed to create account", zap.Error(err), zap.String("email", inv.Content.Email))
			return nil, err
		}
		// Send welcome email
		if err = a.sendWelcomeEmail(account, token); err != nil {
			a.Logger.Warn("Failed to send welcome email for new account created via invitation",
				zap.Error(err), zap.String("email", inv.Content.Email))
			return nil, err
		}
		return account, nil
	} else if err != nil {
		a.Logger.Warn("Failed to fetch account by email", zap.Error(err), zap.String("email", inv.Content.Email))
		return nil, err
	} else {
		// If account already exists, then just join organization
		if err := a.accService.JoinOrganization(ctx, org, account, inv.RoleRef); err != nil {
			a.Logger.Warn("Failed to join organization", zap.Error(err), mzap.StorableRef(account), mzap.StorableRef(org))
			return nil, err
		}
	}

	return account, nil
}

func (a *InvitationAPI) accept(r *http.Request) http.HandlerFunc {
	invitationRef, err := a.irh.GetRef(r)
	if err != nil {
		return a.respondBadReference(r, err)
	}
	var req srequest.AcceptInvitation
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		a.Logger.Warn("Failed to decode request body", zap.Error(err), mzap.ObjRef("invitation_ref", invitationRef))
		return response.BadPayload(a.Logger, a.Name(), err)
	}

	if _, err := a.tf.CreateTransaction().Execute(r.Context(), func(ctx context.Context) (any, error) {
		return nil, a.doAccept(ctx, invitationRef, req.Account)
	}); err != nil {
		a.Logger.Warn("Failed to accept invitation", zap.Error(err), mzap.ObjRef("invitation_ref", invitationRef))
		return response.Auto(a.Logger, a.Name(), err)
	}

	return response.Success(a.Logger)
}