package config

import (
	"fmt"
	"io/ioutil"
	"os"
	"reflect"
	"testing"

	"github.com/hashicorp/terraform/config/lang"
	"github.com/hashicorp/terraform/config/lang/ast"
)

func TestInterpolateFuncConcat(t *testing.T) {
	testFunction(t, testFunctionConfig{
		Cases: []testFunctionCase{
			{
				`${concat("foo", "bar")}`,
				"foobar",
				false,
			},

			{
				`${concat("foo")}`,
				"foo",
				false,
			},

			{
				`${concat()}`,
				nil,
				true,
			},
		},
	})
}

func TestInterpolateFuncFile(t *testing.T) {
	tf, err := ioutil.TempFile("", "tf")
	if err != nil {
		t.Fatalf("err: %s", err)
	}
	path := tf.Name()
	tf.Write([]byte("foo"))
	tf.Close()
	defer os.Remove(path)

	testFunction(t, testFunctionConfig{
		Cases: []testFunctionCase{
			{
				fmt.Sprintf(`${file("%s")}`, path),
				"foo",
				false,
			},

			// Invalid path
			{
				`${file("/i/dont/exist")}`,
				nil,
				true,
			},

			// Too many args
			{
				`${file("foo", "bar")}`,
				nil,
				true,
			},
		},
	})
}

func TestInterpolateFuncJoin(t *testing.T) {
	testFunction(t, testFunctionConfig{
		Cases: []testFunctionCase{
			{
				`${join(",")}`,
				nil,
				true,
			},

			{
				`${join(",", "foo")}`,
				"foo",
				false,
			},

			/*
				TODO
				{
					`${join(",", "foo", "bar")}`,
					"foo,bar",
					false,
				},
			*/

			{
				fmt.Sprintf(`${join(".", "%s")}`,
					fmt.Sprintf(
						"foo%sbar%sbaz",
						InterpSplitDelim,
						InterpSplitDelim)),
				"foo.bar.baz",
				false,
			},
		},
	})
}

func TestInterpolateFuncLookup(t *testing.T) {
	testFunction(t, testFunctionConfig{
		Vars: map[string]ast.Variable{
			"var.foo.bar": ast.Variable{
				Value: "baz",
				Type:  ast.TypeString,
			},
		},
		Cases: []testFunctionCase{
			{
				`${lookup("foo", "bar")}`,
				"baz",
				false,
			},

			// Invalid key
			{
				`${lookup("foo", "baz")}`,
				nil,
				true,
			},

			// Too many args
			{
				`${lookup("foo", "bar", "baz")}`,
				nil,
				true,
			},
		},
	})
}

func TestInterpolateFuncElement(t *testing.T) {
	testFunction(t, testFunctionConfig{
		Cases: []testFunctionCase{
			{
				fmt.Sprintf(`${element("%s", "1")}`,
					"foo"+InterpSplitDelim+"baz"),
				"baz",
				false,
			},

			{
				`${element("foo", "0")}`,
				"foo",
				false,
			},

			// Invalid index should wrap vs. out-of-bounds
			{
				fmt.Sprintf(`${element("%s", "2")}`,
					"foo"+InterpSplitDelim+"baz"),
				"foo",
				false,
			},

			// Too many args
			{
				fmt.Sprintf(`${element("%s", "0", "2")}`,
					"foo"+InterpSplitDelim+"baz"),
				nil,
				true,
			},
		},
	})
}

type testFunctionConfig struct {
	Cases []testFunctionCase
	Vars  map[string]ast.Variable
}

type testFunctionCase struct {
	Input  string
	Result interface{}
	Error  bool
}

func testFunction(t *testing.T, config testFunctionConfig) {
	for i, tc := range config.Cases {
		ast, err := lang.Parse(tc.Input)
		if err != nil {
			t.Fatalf("%d: err: %s", i, err)
		}

		out, _, err := lang.Eval(ast, langEvalConfig(config.Vars))
		if (err != nil) != tc.Error {
			t.Fatalf("%d: err: %s", i, err)
		}

		if !reflect.DeepEqual(out, tc.Result) {
			t.Fatalf("%d: bad: %#v", i, out)
		}
	}
}