todos.go

package main

import (
	"encoding/json"
	"log"
	"net/http"
	"strings"
	"time"
)

type Todo struct {
	TodoId      int64
	Description string
	HasDueDate  bool
	DueDate     time.Time
	HasReminder bool
	Reminder    time.Time
	Tags        string //tags are joined together by newlines \n
	Notes       string
	Completed   bool
	UserId      int64 `json:"-"`
}

type TodoList struct {
	Todos *[]Todo `json:"todos"`
}

func (t *Todo) Write(w http.ResponseWriter) error {
	enc := json.NewEncoder(w)
	return enc.Encode(t)
}

func (t *Todo) Read(json_str string) error {
	dec := json.NewDecoder(strings.NewReader(json_str))
	return dec.Decode(t)
}

func (t *Todo) MarkReminded() error {
	_, err := DB.Exec("UPDATE todos SET HasReminder=? WHERE UserId=? AND TodoId=? AND Reminder=?;", false, t.UserId, t.TodoId, t.Reminder)
	return err
}

func (tl *TodoList) Write(w http.ResponseWriter) error {
	enc := json.NewEncoder(w)
	return enc.Encode(tl)
}

func GetTodo(todoid int64, userid int64) (*Todo, error) {
	var t Todo

	err := DB.SelectOne(&t, "SELECT * from todos where UserId=? AND TodoId=?", userid, todoid)
	if err != nil {
		return nil, err
	}
	return &t, nil
}

/*
 * Use sparingly, and only when you're sure you're checking if the user has the
 * authentication necessary to access this todo.
 */
func GetTodoNoUserId(todoid int64) (*Todo, error) {
	var t Todo

	err := DB.SelectOne(&t, "SELECT * from todos where TodoId=?", todoid)
	if err != nil {
		return nil, err
	}
	return &t, nil
}

func GetTodos(userid int64) (*[]Todo, error) {
	var todos []Todo

	_, err := DB.Select(&todos, "SELECT * from todos where UserId=?", userid)
	if err != nil {
		return nil, err
	}
	return &todos, nil
}

func TodoHandler(w http.ResponseWriter, r *http.Request) {
	user, err := GetUserFromSession(r)
	if err != nil {
		WriteError(w, 1 /*Not Signed In*/)
		return
	}

	if r.Method == "POST" {
		todo_json := r.PostFormValue("todo")
		if todo_json == "" {
			WriteError(w, 3 /*Invalid Request*/)
			return
		}

		var todo Todo
		err := todo.Read(todo_json)
		if err != nil {
			WriteError(w, 3 /*Invalid Request*/)
			return
		}
		todo.TodoId = -1
		todo.UserId = user.UserId

		err = DB.Insert(&todo)
		if err != nil {
			WriteError(w, 999 /*Internal Error*/)
			log.Print(err)
			return
		}

		WriteSuccess(w)
	} else if r.Method == "GET" {
		todoid, err := GetURLID(r.URL.Path)
		if err != nil {
			//Return all TODOs
			var tl TodoList
			todos, err := GetTodos(user.UserId)
			if err != nil {
				WriteError(w, 999 /*Internal Error*/)
				log.Print(err)
				return
			}
			tl.Todos = todos
			err = (&tl).Write(w)
			if err != nil {
				WriteError(w, 999 /*Internal Error*/)
				log.Print(err)
				return
			}
		} else {
			//Return Todo with this Id
			todo, err := GetTodo(todoid, user.UserId)
			if err != nil {
				WriteError(w, 3 /*Invalid Request*/)
				return
			}
			err = todo.Write(w)
			if err != nil {
				WriteError(w, 999 /*Internal Error*/)
				log.Print(err)
				return
			}
		}
	} else {
		todoid, err := GetURLID(r.URL.Path)
		if err != nil {
			WriteError(w, 3 /*Invalid Request*/)
			return
		}
		if r.Method == "PUT" {
			todo_json := r.PostFormValue("todo")
			if todo_json == "" {
				WriteError(w, 3 /*Invalid Request*/)
				return
			}

			var todo Todo
			err := todo.Read(todo_json)
			if err != nil || todo.TodoId != todoid {
				WriteError(w, 3 /*Invalid Request*/)
				return
			}
			todo.UserId = user.UserId

			count, err := DB.Update(&todo)
			if count != 1 || err != nil {
				WriteError(w, 999 /*Internal Error*/)
				log.Print(err)
				return
			}

			WriteSuccess(w)
		} else if r.Method == "DELETE" {
			var todo Todo
			todo.TodoId = todoid
			count, err := DB.Delete(&todo)
			//TODO detect if this error was due to the key missing or something else, we could be returning an internal error here when the TodoId was just supplied wrong
			if count != 1 || err != nil {
				WriteError(w, 999 /*Internal Error*/)
				log.Print(err)
				return
			}

			WriteSuccess(w)
		}
	}
}