main.go

package main

import (
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"
)

type todo struct {
	ID 					string `json:"id"`
	Item 				string `json: "title"`
	Completed 	bool 	 `json:"completed"`
}

func main() {
	router := gin.Default()
	router.GET("/", homepage)
	router.GET("/todos", getTodos)
	router.POST("/todos", addTodo)
	router.GET("/todos/:id", getTodos)
	router.PATCH("/todos/:id", toggleTodoStatus)
	router.Run(":3000")
}


var todos = []todo{
	{ID:"1", Item: "Wash the dishes", Completed: true},
	{ID:"2", Item: "Clean the room", Completed: false},
	{ID:"3", Item: "Apply for admission", Completed: true},
}

func homepage(context *gin.Context){
	context.JSON(http.StatusOK, gin.H{"Topic": "Todo List API"})
}

func getTodos(context *gin.Context ){
	context.IndentedJSON(http.StatusOK, todos)
}

func addTodo(context *gin.Context){
	var newTodo todo

	if err := context.BindJSON(&newTodo); err != nil {
		return
	}
	todos = append(todos, newTodo)
	context.IndentedJSON(http.StatusCreated, newTodo)

}
 func getTodoById(id string) (*todo, error) {
	for i, t := range todos {
		if t.ID == id {
			return &todos[i], nil
		}
	}
		return nil, errors.New("todo not found")
}

func getTodo(context *gin.Context) {
	id := context.Param("id")
	todo, err := getTodoById(id)
	// check error
	if err != nil {
		context.IndentedJSON(http.StatusNotFound, gin.H{"message":"Todo not found"})
		return 
	}
	context.IndentedJSON(http.StatusOK, todo)
}

func toggleTodoStatus(context *gin.Context){
	id := context.Param("id")
	todo, err := getTodoById(id)

	if err != nil {
		context.IndentedJSON(http.StatusNotFound, gin.H{"message":"Todo is not found"})
		return 
	}
	todo.Completed = !todo.Completed
	context.IndentedJSON(http.StatusOK, todo)
}