/*
   Copyright 2014 CoreOS, Inc.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package pkg

import (
	"fmt"
	"io"
	"math"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"
)

func TestExpBackoff(t *testing.T) {
	duration := time.Millisecond
	max := time.Hour
	for i := 0; i < math.MaxUint16; i++ {
		duration = ExpBackoff(duration, max)
		if duration < 0 {
			t.Fatalf("duration too small: %v %v", duration, i)
		}
		if duration > max {
			t.Fatalf("duration too large: %v %v", duration, i)
		}
	}
}

// Test exponential backoff and that it continues retrying if a 5xx response is
// received
func TestGetURLExpBackOff(t *testing.T) {
	var expBackoffTests = []struct {
		count int
		body  string
	}{
		{0, "number of attempts: 0"},
		{1, "number of attempts: 1"},
		{2, "number of attempts: 2"},
	}
	client := NewHttpClient()

	for i, tt := range expBackoffTests {
		mux := http.NewServeMux()
		count := 0
		mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
			if count == tt.count {
				io.WriteString(w, fmt.Sprintf("number of attempts: %d", count))
				return
			}
			count++
			http.Error(w, "", 500)
		})
		ts := httptest.NewServer(mux)
		defer ts.Close()

		data, err := client.GetRetry(ts.URL)
		if err != nil {
			t.Errorf("Test case %d produced error: %v", i, err)
		}

		if count != tt.count {
			t.Errorf("Test case %d failed: %d != %d", i, count, tt.count)
		}

		if string(data) != tt.body {
			t.Errorf("Test case %d failed: %s != %s", i, tt.body, data)
		}
	}
}

// Test that it stops retrying if a 4xx response comes back
func TestGetURL4xx(t *testing.T) {
	client := NewHttpClient()
	retries := 0
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		retries++
		http.Error(w, "", 404)
	}))
	defer ts.Close()

	_, err := client.GetRetry(ts.URL)
	if err == nil {
		t.Errorf("Incorrect result\ngot:  %s\nwant: %s", err.Error(), "Not found. HTTP status code: 404")
	}

	if retries > 1 {
		t.Errorf("Number of retries:\n%d\nExpected number of retries:\n%s", retries, 1)
	}
}

// Test that it fetches and returns user-data just fine
func TestGetURL2xx(t *testing.T) {
	var cloudcfg = `
#cloud-config
coreos: 
	oem:
	    id: test
	    name: CoreOS.box for Test
	    version-id: %VERSION_ID%+%BUILD_ID%
	    home-url: https://github.com/coreos/coreos-cloudinit
	    bug-report-url: https://github.com/coreos/coreos-cloudinit
	update:
		reboot-strategy: best-effort
`

	client := NewHttpClient()
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprint(w, cloudcfg)
	}))
	defer ts.Close()

	data, err := client.GetRetry(ts.URL)
	if err != nil {
		t.Errorf("Incorrect result\ngot:  %v\nwant: %v", err, nil)
	}

	if string(data) != cloudcfg {
		t.Errorf("Incorrect result\ngot:  %s\nwant: %s", string(data), cloudcfg)
	}
}

// Test attempt to fetching using malformed URL
func TestGetMalformedURL(t *testing.T) {
	client := NewHttpClient()

	var tests = []struct {
		url  string
		want string
	}{
		{"boo", "URL boo does not have a valid HTTP scheme. Skipping."},
		{"mailto://boo", "URL mailto://boo does not have a valid HTTP scheme. Skipping."},
		{"ftp://boo", "URL ftp://boo does not have a valid HTTP scheme. Skipping."},
		{"", "URL is empty. Skipping."},
	}

	for _, test := range tests {
		_, err := client.GetRetry(test.url)
		if err == nil || err.Error() != test.want {
			t.Errorf("Incorrect result\ngot:  %v\nwant: %v", err, test.want)
		}
	}
}