package controllers

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"strconv"

	"git.aiterp.net/lucifer/lucifer/internal/httperr"

	"git.aiterp.net/lucifer/lucifer/internal/respond"
	"git.aiterp.net/lucifer/lucifer/models"
	"github.com/gorilla/mux"
)

// The GroupController is a controller for all group stuff.
type GroupController struct {
	groups models.GroupRepository
	users  models.UserRepository
	lights models.LightRepository
}

// getGroups (`GET /:id`): Get user by id
func (c *GroupController) getGroups(w http.ResponseWriter, r *http.Request) {
	user := models.UserFromContext(r.Context())

	groups, err := c.groups.ListByUser(r.Context(), *user)
	if err != nil {
		log.Printf("Getting groups for user %s (%d) failed: %s", user.Name, user.ID, err)
		respond.Error(w, http.StatusInternalServerError, "internal_error", "Failed to get groups.")
		return
	}

	respond.Data(w, groups)
}

// getGroup (`GET /:group_id`): Get user by id
func (c *GroupController) getGroup(w http.ResponseWriter, r *http.Request) {
	session := models.SessionFromContext(r.Context())

	idStr := mux.Vars(r)["group_id"]
	id, err := strconv.ParseInt(idStr, 10, 32)
	if err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_id", "The id"+idStr+"is not valid.")
		return
	}

	group, err := c.groups.FindByID(r.Context(), int(id))
	if err != nil || !group.Permission(session.UserID).Read {
		respond.Error(w, http.StatusNotFound, "not_found", "The group cannot be found or you are not authorized to view it.")
		return
	}

	respond.Data(w, group)
}

// getGroupLights (`GET /:group_id/light/`): Get user by id
func (c *GroupController) getGroupLights(w http.ResponseWriter, r *http.Request) {
	session := models.SessionFromContext(r.Context())

	idStr := mux.Vars(r)["group_id"]
	id, err := strconv.ParseInt(idStr, 10, 32)
	if err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_id", "The id "+idStr+" is not valid.")
		return
	}

	group, err := c.groups.FindByID(r.Context(), int(id))
	if err != nil || !group.Permission(session.UserID).Read {
		respond.Error(w, http.StatusNotFound, "group_not_found", "The group cannot be found or you are not authorized to view it.")
		return
	}

	lights, err := c.lights.ListByGroup(r.Context(), group)
	if err != nil && err != sql.ErrNoRows {
		log.Printf("Getting lights for group %s (%d) failed: %s", group.Name, group.ID, err)
		respond.Error(w, http.StatusInternalServerError, "internal_error", "Failed to get groups.")
		return
	}

	respond.Data(w, lights)
}

// getGroupLight (`GET /:group_id/light/:light_id`): Get user by id
func (c *GroupController) getGroupLight(w http.ResponseWriter, r *http.Request) {
	session := models.SessionFromContext(r.Context())

	groupIDStr := mux.Vars(r)["group_id"]
	groupID, err := strconv.ParseInt(groupIDStr, 10, 32)
	if err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_id", "The group id "+groupIDStr+" is not valid.")
		return
	}

	idStr := mux.Vars(r)["light_id"]
	id, err := strconv.ParseInt(idStr, 10, 32)
	if err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_id", "The light id "+idStr+" is not valid.")
		return
	}

	group, err := c.groups.FindByID(r.Context(), int(groupID))
	if err != nil || !group.Permission(session.UserID).Read {
		respond.Error(w, http.StatusNotFound, "group_not_found", "The group cannot be found or you are not authorized to view it.")
		return
	}

	light, err := c.lights.FindByID(r.Context(), int(id))
	if err != nil || light.GroupID != group.ID {
		fmt.Println(light, id)
		respond.Error(w, http.StatusNotFound, "light_not_found", "The light cannot be found in this group.")
		return
	}

	respond.Data(w, light)
}

// postGroup (`POST /`): Create a group.
func (c *GroupController) postGroup(w http.ResponseWriter, r *http.Request) {
	user := models.UserFromContext(r.Context())

	postData := struct {
		Name string
	}{}
	if err := json.NewDecoder(r.Body).Decode(&postData); err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_json", "Input is not valid JSON.")
		return
	}
	if postData.Name == "" {
		respond.Error(w, http.StatusBadRequest, "invalid_name", "The name cannot be blank.")
		return
	}

	group, err := c.groups.Insert(r.Context(), models.Group{Name: postData.Name})
	if err != nil {
		httperr.Respond(w, err)
		return
	}

	permission := models.GroupPermission{
		GroupID: group.ID,
		UserID:  user.ID,
		Read:    true,
		Write:   true,
		Delete:  true,
		Create:  true,
		Manage:  true,
	}

	err = c.groups.UpdatePermissions(r.Context(), permission)
	if err != nil {
		httperr.Respond(w, err)
		return
	}

	group.Permissions = []models.GroupPermission{permission}
	respond.Data(w, group)
}

// updateGroup (`PUT/PATCH /:group_id`): Create a group.
func (c *GroupController) updateGroup(w http.ResponseWriter, r *http.Request) {
	user := models.UserFromContext(r.Context())

	groupIDStr := mux.Vars(r)["group_id"]
	groupID, err := strconv.ParseInt(groupIDStr, 10, 32)
	if err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_id", "The group id "+groupIDStr+" is not valid.")
		return
	}

	postData := struct {
		Name string
	}{}
	if err := json.NewDecoder(r.Body).Decode(&postData); err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_json", "Input is not valid JSON.")
		return
	}
	if postData.Name == "" {
		respond.Error(w, http.StatusBadRequest, "invalid_name", "The name cannot be blank.")
		return
	}

	group, err := c.groups.FindByID(r.Context(), int(groupID))
	if err != nil {
		respond.Error(w, http.StatusNotFound, "group_not_found", "The group cannot be found or you are not authorized to view it.")
		return
	} else if !group.Permission(user.ID).Manage {
		respond.Error(w, http.StatusNotFound, "permission_denied", "Your transgression will be remembered.")
		return
	}

	group.Name = postData.Name
	err = c.groups.Update(r.Context(), group)
	if err != nil {
		httperr.Respond(w, err)
		return
	}

	respond.Data(w, group)
}

// updateGroupPermission (`PUT/PATCH /:group_id/permission/:user_id`): Update a user's permission on a group.
func (c *GroupController) updateGroupPermission(w http.ResponseWriter, r *http.Request) {
	user := models.UserFromContext(r.Context())

	groupIDStr := mux.Vars(r)["group_id"]
	groupID, err := strconv.ParseInt(groupIDStr, 10, 32)
	if err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_id", "The group id "+groupIDStr+" is not valid.")
		return
	}

	userIDStr := mux.Vars(r)["user_id"]
	userID, err := strconv.ParseInt(userIDStr, 10, 32)
	if err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_id", "The user id "+userIDStr+" is not valid.")
		return
	}

	putData := struct {
		Read   *bool `json:"read"`
		Write  *bool `json:"write"`
		Create *bool `json:"create"`
		Delete *bool `json:"delete"`
		Manage *bool `json:"manage"`
	}{}
	if err := json.NewDecoder(r.Body).Decode(&putData); err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_json", "Input is not valid JSON.")
		return
	}
	if putData.Manage != nil {
		respond.Error(w, http.StatusBadRequest, "cannot_change_manage", "You cannot change the manage permission.")
		return
	}

	group, err := c.groups.FindByID(r.Context(), int(groupID))
	if err != nil {
		respond.Error(w, http.StatusNotFound, "group_not_found", "The group could not be found.")
		return
	} else if !group.Permission(user.ID).Manage {
		respond.Error(w, http.StatusForbidden, "permission_denied", "This transgression has been dispatched to the North Pole for review.")
		return
	}

	user2, err := c.users.FindByID(r.Context(), int(userID))
	if err == sql.ErrNoRows {
		respond.Error(w, http.StatusNotFound, "user_not_Found", "The user could not be found.")
		return
	} else if err != nil {
		httperr.Respond(w, err)
		return
	}

	permissions := group.Permission(user2.ID)
	if putData.Read != nil {
		permissions.Read = *putData.Read
	}
	if putData.Write != nil {
		permissions.Write = *putData.Write
	}
	if putData.Create != nil {
		permissions.Create = *putData.Create
	}
	if putData.Delete != nil {
		permissions.Delete = *putData.Delete
	}

	err = c.groups.UpdatePermissions(r.Context(), permissions)
	if err != nil {
		httperr.Respond(w, err)
		return
	}

	respond.Data(w, permissions)
}

// deleteGroup (`DELETE /:group_id`): Delete a group.
func (c *GroupController) deleteGroup(w http.ResponseWriter, r *http.Request) {
	user := models.UserFromContext(r.Context())

	groupIDStr := mux.Vars(r)["group_id"]
	groupID, err := strconv.ParseInt(groupIDStr, 10, 32)
	if err != nil {
		respond.Error(w, http.StatusBadRequest, "invalid_id", "The group id "+groupIDStr+" is not valid.")
		return
	}

	group, err := c.groups.FindByID(r.Context(), int(groupID))
	if err != nil {
		respond.Error(w, http.StatusNotFound, "group_not_found", "The group cannot be found.")
		return
	} else if !group.Permission(user.ID).Manage {
		respond.Error(w, http.StatusNotFound, "permission_denied", "Your transgression will be remembered.")
		return
	}

	lights, err := c.lights.ListByGroup(r.Context(), group)
	if err != nil && err != sql.ErrNoRows {
		httperr.Respond(w, err)
		return
	}

	for _, light := range lights {
		light.GroupID = 0
		err := c.lights.Update(r.Context(), light)
		if err != nil {
			httperr.Respond(w, err)
			return
		}
	}

	err = c.groups.Remove(r.Context(), group)
	if err != nil {
		httperr.Respond(w, err)
		return
	}

	respond.Data(w, group)
}

// Mount mounts the controller
func (c *GroupController) Mount(router *mux.Router, prefix string) {
	sub := router.PathPrefix(prefix).Subrouter()

	sub.HandleFunc("/", c.getGroups).Methods("GET")
	sub.HandleFunc("/", c.postGroup).Methods("POST")
	sub.HandleFunc("/{group_id}", c.getGroup).Methods("GET")
	sub.HandleFunc("/{group_id}", c.updateGroup).Methods("PUT", "PATCH")
	sub.HandleFunc("/{group_id}", c.deleteGroup).Methods("DELETE")
	sub.HandleFunc("/{group_id}/permission/{user_id}", c.updateGroupPermission).Methods("PUT", "PATCH")
	sub.HandleFunc("/{group_id}/light/", c.getGroupLights).Methods("GET")
	sub.HandleFunc("/{group_id}/light/{light_id}", c.getGroupLight).Methods("GET")
}

// NewGroupController creates a new GroupController.
func NewGroupController(groups models.GroupRepository, users models.UserRepository, lights models.LightRepository) *GroupController {
	return &GroupController{groups: groups, users: users, lights: lights}
}