package api

import (
	"errors"
	"net/http"
	"strings"
	"time"

	"gardomatic.kleiax.de/internal/platform/validate"
	"gardomatic.kleiax.de/internal/storage"
	"github.com/julienschmidt/httprouter"
)

func (app *application) listGardenMembersHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	members, err := app.models.GardenMembers.GetAllForGarden(gardenID)
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	if err = app.writeJSON(w, http.StatusOK, envelope{"members": members}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func canManageMember(target, replacement storage.GardenRole) bool {
	return target != storage.GardenRoleOwner && replacement != storage.GardenRoleOwner
}

func (app *application) updateGardenMemberHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	userID, err := app.readNamedIDParam(r, "userID")
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	var input struct {
		Role storage.GardenRole `json:"role"`
	}
	if err = app.readJSON(w, r, &input); err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	_, roleErr := app.models.Roles.GetForGarden(gardenID, string(input.Role))
	if roleErr != nil || input.Role == storage.GardenRoleOwner {
		app.failedValidationResponse(w, r, map[string]string{"role": "must be a garden role; ownership must be transferred separately"})
		return
	}
	target, err := app.models.GardenMembers.Get(gardenID, userID)
	if err != nil {
		app.respondToMemberError(w, r, err)
		return
	}
	if !canManageMember(target.Role, input.Role) {
		app.permissionDeniedResponse(w, r)
		return
	}
	target.Role = input.Role
	target, err = app.models.GardenMembers.Update(target)
	if err != nil {
		app.respondToMemberError(w, r, err)
		return
	}
	if err = app.writeJSON(w, http.StatusOK, envelope{"member": target}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) deleteGardenMemberHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	userID, err := app.readNamedIDParam(r, "userID")
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	target, err := app.models.GardenMembers.Get(gardenID, userID)
	if err != nil {
		app.respondToMemberError(w, r, err)
		return
	}
	if !canManageMember(target.Role, storage.GardenRoleViewer) {
		app.permissionDeniedResponse(w, r)
		return
	}
	if err = app.models.GardenMembers.Delete(gardenID, userID); err != nil {
		app.respondToMemberError(w, r, err)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (app *application) transferGardenOwnershipHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	toUserID, err := app.readNamedIDParam(r, "userID")
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	actor, _ := app.contextGetGardenMember(r)
	if err = app.models.GardenMembers.TransferOwnership(gardenID, actor.UserID, toUserID); err != nil {
		app.respondToMemberError(w, r, err)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (app *application) listGardenInvitesHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	invites, err := app.models.GardenInvites.GetAllForGarden(gardenID)
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	if err = app.writeJSON(w, http.StatusOK, envelope{"invites": invites}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) createGardenInviteHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	actor, _ := app.contextGetGardenMember(r)
	var input struct {
		Email string             `json:"email"`
		Role  storage.GardenRole `json:"role"`
	}
	if err := app.readJSON(w, r, &input); err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	input.Email = strings.ToLower(strings.TrimSpace(input.Email))
	v := validate.New()
	storage.ValidateEmail(v, input.Email)
	_, roleErr := app.models.Roles.GetForGarden(gardenID, string(input.Role))
	if roleErr != nil || input.Role == storage.GardenRoleOwner {
		v.AddError("role", "role may not be granted")
	}
	if !v.Valid() {
		app.failedValidationResponse(w, r, v.Errors)
		return
	}
	invite, err := app.models.GardenInvites.Upsert(storage.GardenInvite{GardenID: gardenID, Email: input.Email, Role: input.Role, InvitedBy: actor.UserID, ExpiresAt: time.Now().Add(7 * 24 * time.Hour)})
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	inviteEmail := invite.Email
	inviteURL := strings.TrimRight(app.config.WebBaseURL, "/") + "/invite?token=" + invite.Token
	app.background(func() {
		data := map[string]any{"inviteURL": inviteURL}
		if sendErr := app.mailer.Send(inviteEmail, "garden_invite.tmpl", data); sendErr != nil {
			app.logger.Error(sendErr.Error())
		}
	})
	invite.Token = ""
	if err = app.writeJSON(w, http.StatusCreated, envelope{"invite": invite}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) deleteGardenInviteHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	inviteID, err := app.readNamedIDParam(r, "inviteID")
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	if err = app.models.GardenInvites.Delete(gardenID, inviteID); err != nil {
		app.respondToMemberError(w, r, err)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (app *application) acceptGardenInviteHandler(w http.ResponseWriter, r *http.Request) {
	token := httprouter.ParamsFromContext(r.Context()).ByName("token")
	user, _ := app.contextGetAuthenticatedUser(r)
	member, err := app.models.GardenInvites.Accept(token, user)
	if err != nil {
		app.respondToMemberError(w, r, err)
		return
	}
	if err = app.writeJSON(w, http.StatusOK, envelope{"member": member}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) respondToMemberError(w http.ResponseWriter, r *http.Request, err error) {
	switch {
	case errors.Is(err, storage.ErrRecordNotFound):
		app.notFoundResponse(w, r)
	case errors.Is(err, storage.ErrConflict):
		app.conflictResponse(w, r)
	default:
		app.serverErrorResponse(w, r, err)
	}
}