• A promise is an object representing the eventual completion or failure of an asynchronous operation.
• A PATTERN for writing async code
• Resolve and reject

• / THE CALLBACK VERSION
  const fakeRequestCallback = (url, success, failure) => {
      const delay = Math.floor(Math.random() * 4500) + 500;
      setTimeout(() => {
          if (delay > 4000) {
              failure('Connection Timeout :(')
          } else {
              success(`Here is your fake data from ${url}`)
          }
      }, delay)
  }
  // THE PROMISE VERSION 
  const fakeRequestPromise = (url) => {
      return new Promise((resolve, reject) => {
          const delay = Math.floor(Math.random() * (4500)) + 500;
          setTimeout(() => {
              if (delay > 4000) {
                  reject('Connection Timeout :(')
              } else {
                  resolve(`Here is your fake data from ${url}`)
              }
          }, delay)
      })
  }

   

// fakeRequestPromise('yelp.com/api/coffee/page1')
//     .then(() => {
//         console.log("IT WORKED!!!!!! (page1)")
//         fakeRequestPromise('yelp.com/api/coffee/page2')
//             .then(() => {
//                 console.log("IT WORKED!!!!!! (page2)")
//                 fakeRequestPromise('yelp.com/api/coffee/page3')
//                     .then(() => {
//                         console.log("IT WORKED!!!!!! (page3)")
//                     })
//                     .catch(() => {
//                         console.log("OH NO, ERROR!!! (page3)")
//                     })
//             })
//             .catch(() => {
//                 console.log("OH NO, ERROR!!! (page2)")
//             })
//     })
//     .catch(() => {
//         console.log("OH NO, ERROR!!! (page1)")
//     })


// THE CLEANEST OPTION WITH THEN/CATCH
// RETURN A PROMISE FROM .THEN() CALLBACK SO WE CAN CHAIN!
fakeRequestPromise('yelp.com/api/coffee/page1')
    .then((data) => {
        console.log("IT WORKED!!!!!! (page1)")
        console.log(data)
        return fakeRequestPromise('yelp.com/api/coffee/page2')
    })
    .then((data) => {
        console.log("IT WORKED!!!!!! (page2)")
        console.log(data)
        return fakeRequestPromise('yelp.com/api/coffee/page3')
    })
    .then((data) => {
        console.log("IT WORKED!!!!!! (page3)")
        console.log(data)
    })
    .catch((err) => {
        console.log("OH NO, A REQUEST FAILED!!!")
        console.log(err)
    })

const fakeRequest = (url) => {
    return new Promise((resolve, reject) => {
        const rand = Math.random();
        setTimeout(() => {
            if (rand < 0.7) {
                resolve('YOUR FAKE DATA HERE');
            }
            reject('Request Error!');
        }, 1000)
    })
}

fakeRequest('/dogs/1')
    .then((data) => {
        console.log("DONE WITH REQUEST!")
        console.log('data is:', data)
    })
    .catch((err) => {
        console.log("OH NO!", err)
    })

using promise to creat rainbow change color

const delayedColorChange = (color, delay) => {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            document.body.style.backgroundColor = color;
            resolve();
        }, delay)
    })
}


delayedColorChange('red', 1000)
    .then(() => delayedColorChange('orange', 1000))
    .then(() => delayedColorChange('yellow', 1000))
    .then(() => delayedColorChange('green', 1000))
    .then(() => delayedColorChange('blue', 1000))
    .then(() => delayedColorChange('indigo', 1000))
    .then(() => delayedColorChange('violet', 1000))