/*
Copyright 2011 Google 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 osutil

import (
	"fmt"
	"os"
	"testing"
)

// Creates a file with the content "test" at path
func createTestInclude(path string) error {
	// Create a config file for OpenCamliInclude to play with
	cf, e := os.Create(path)
	if e != nil {
		return e
	}
	fmt.Fprintf(cf, "test")
	return cf.Close()
}

// Calls OpenCamliInclude to open path, and checks that it containts "test"
func checkOpen(t *testing.T, path string) {
	found, e := FindCamliInclude(path)
	if e != nil {
		t.Errorf("Failed to find %v", path)
		return
	}
	var file *os.File
	file, e = os.Open(found)
	if e != nil {
		t.Errorf("Failed to open %v", path)
	} else {
		var d [10]byte
		if n, _ := file.Read(d[:]); n != 4 {
			t.Errorf("Read incorrect number of chars from test.config, wrong file?")
		}
		if string(d[0:4]) != "test" {
			t.Errorf("Wrong test file content: %v", string(d[0:4]))
		}
		file.Close()
	}
}

// Test for error when file doesn't exist
func TestOpenCamliIncludeNoFile(t *testing.T) {
	// Test that error occurs if no such file
	const notExist = "this_config_doesnt_exist.config"
	_, e := FindCamliInclude(notExist)
	if e == nil {
		t.Errorf("Successfully opened config which doesn't exist: %v", notExist)
	}
}

// Test for when a file exists in CWD
func TestOpenCamliIncludeCWD(t *testing.T) {
	const path string = "TestOpenCamliIncludeCWD.config"
	if e := createTestInclude(path); e != nil {
		t.Errorf("Couldn't create test config file, aborting test: %v", e)
		return
	}
	defer os.Remove(path)

	checkOpen(t, path)
}

// Test for when a file exists in CAMLI_CONFIG_DIR
func TestOpenCamliIncludeDir(t *testing.T) {
	const name string = "TestOpenCamliIncludeDir.config"
	if e := createTestInclude("/tmp/" + name); e != nil {
		t.Errorf("Couldn't create test config file, aborting test: %v", e)
		return
	}
	defer os.Remove("/tmp/" + name)
	os.Setenv("CAMLI_CONFIG_DIR", "/tmp")
	defer os.Setenv("CAMLI_CONFIG_DIR", "")

	checkOpen(t, name)
}

// Test for when a file exits in CAMLI_INCLUDE_PATH
func TestOpenCamliIncludePath(t *testing.T) {
	const name string = "TestOpenCamliIncludePath.config"
	if e := createTestInclude("/tmp/" + name); e != nil {
		t.Errorf("Couldn't create test config file, aborting test: %v", e)
		return
	}
	defer os.Remove("/tmp/" + name)
	defer os.Setenv("CAMLI_INCLUDE_PATH", "")

	os.Setenv("CAMLI_INCLUDE_PATH", "/tmp")
	checkOpen(t, name)

	os.Setenv("CAMLI_INCLUDE_PATH", "/not/a/camli/config/dir:/tmp")
	checkOpen(t, name)

	os.Setenv("CAMLI_INCLUDE_PATH", "/not/a/camli/config/dir:/tmp:/another/fake/camli/dir")
	checkOpen(t, name)
}