package configs

import (
	"testing"

	"github.com/google/go-cmp/cmp"
	"github.com/hashicorp/hcl/v2"
	"github.com/hashicorp/hcl/v2/hcltest"
	"github.com/hashicorp/terraform/internal/addrs"
)

func TestDecodeMovedBlock(t *testing.T) {
	blockRange := hcl.Range{
		Filename: "mock.tf",
		Start:    hcl.Pos{Line: 3, Column: 12, Byte: 27},
		End:      hcl.Pos{Line: 3, Column: 19, Byte: 34},
	}

	foo_expr := hcltest.MockExprTraversalSrc("test_instance.foo")
	bar_expr := hcltest.MockExprTraversalSrc("test_instance.bar")

	foo_index_expr := hcltest.MockExprTraversalSrc("test_instance.foo[1]")
	bar_index_expr := hcltest.MockExprTraversalSrc("test_instance.bar[\"one\"]")

	mod_foo_expr := hcltest.MockExprTraversalSrc("module.foo")
	mod_bar_expr := hcltest.MockExprTraversalSrc("module.bar")

	tests := map[string]struct {
		input *hcl.Block
		want  *Moved
		err   string
	}{
		"success": {
			&hcl.Block{
				Type: "moved",
				Body: hcltest.MockBody(&hcl.BodyContent{
					Attributes: hcl.Attributes{
						"from": {
							Name: "from",
							Expr: foo_expr,
						},
						"to": {
							Name: "to",
							Expr: bar_expr,
						},
					},
				}),
				DefRange: blockRange,
			},
			&Moved{
				From:      mustMoveEndpointFromExpr(foo_expr),
				To:        mustMoveEndpointFromExpr(bar_expr),
				DeclRange: blockRange,
			},
			``,
		},
		"indexed resources": {
			&hcl.Block{
				Type: "moved",
				Body: hcltest.MockBody(&hcl.BodyContent{
					Attributes: hcl.Attributes{
						"from": {
							Name: "from",
							Expr: foo_index_expr,
						},
						"to": {
							Name: "to",
							Expr: bar_index_expr,
						},
					},
				}),
				DefRange: blockRange,
			},
			&Moved{
				From:      mustMoveEndpointFromExpr(foo_index_expr),
				To:        mustMoveEndpointFromExpr(bar_index_expr),
				DeclRange: blockRange,
			},
			``,
		},
		"modules": {
			&hcl.Block{
				Type: "moved",
				Body: hcltest.MockBody(&hcl.BodyContent{
					Attributes: hcl.Attributes{
						"from": {
							Name: "from",
							Expr: mod_foo_expr,
						},
						"to": {
							Name: "to",
							Expr: mod_bar_expr,
						},
					},
				}),
				DefRange: blockRange,
			},
			&Moved{
				From:      mustMoveEndpointFromExpr(mod_foo_expr),
				To:        mustMoveEndpointFromExpr(mod_bar_expr),
				DeclRange: blockRange,
			},
			``,
		},
		"error: missing argument": {
			&hcl.Block{
				Type: "moved",
				Body: hcltest.MockBody(&hcl.BodyContent{
					Attributes: hcl.Attributes{
						"from": {
							Name: "from",
							Expr: foo_expr,
						},
					},
				}),
				DefRange: blockRange,
			},
			&Moved{
				From:      mustMoveEndpointFromExpr(foo_expr),
				DeclRange: blockRange,
			},
			"Missing required argument",
		},
		"error: type mismatch": {
			&hcl.Block{
				Type: "moved",
				Body: hcltest.MockBody(&hcl.BodyContent{
					Attributes: hcl.Attributes{
						"to": {
							Name: "to",
							Expr: foo_expr,
						},
						"from": {
							Name: "from",
							Expr: mod_foo_expr,
						},
					},
				}),
				DefRange: blockRange,
			},
			&Moved{
				To:        mustMoveEndpointFromExpr(foo_expr),
				From:      mustMoveEndpointFromExpr(mod_foo_expr),
				DeclRange: blockRange,
			},
			"Invalid \"moved\" addresses",
		},
	}

	for name, test := range tests {
		t.Run(name, func(t *testing.T) {
			got, diags := decodeMovedBlock(test.input)

			if diags.HasErrors() {
				if test.err == "" {
					t.Fatalf("unexpected error: %s", diags.Errs())
				}
				if gotErr := diags[0].Summary; gotErr != test.err {
					t.Errorf("wrong error, got %q, want %q", gotErr, test.err)
				}
			} else if test.err != "" {
				t.Fatal("expected error")
			}

			if !cmp.Equal(got, test.want, cmp.AllowUnexported(addrs.MoveEndpoint{})) {
				t.Fatalf("wrong result: %s", cmp.Diff(got, test.want))
			}
		})
	}
}

func TestMovedBlocksInModule(t *testing.T) {
	parser := NewParser(nil)
	mod, diags := parser.LoadConfigDir("testdata/valid-modules/moved-blocks")
	if diags.HasErrors() {
		t.Errorf("unexpected error: %s", diags.Error())
	}

	var gotPairs [][2]string
	for _, mc := range mod.Moved {
		gotPairs = append(gotPairs, [2]string{mc.From.String(), mc.To.String()})
	}
	wantPairs := [][2]string{
		{`test.foo`, `test.bar`},
		{`test.foo`, `test.bar["bloop"]`},
		{`module.a`, `module.b`},
		{`module.a`, `module.a["foo"]`},
		{`test.foo`, `module.a.test.foo`},
		{`data.test.foo`, `data.test.bar`},
	}
	if diff := cmp.Diff(wantPairs, gotPairs); diff != "" {
		t.Errorf("wrong addresses\n%s", diff)
	}
}

func mustMoveEndpointFromExpr(expr hcl.Expression) *addrs.MoveEndpoint {
	traversal, hcldiags := hcl.AbsTraversalForExpr(expr)
	if hcldiags.HasErrors() {
		panic(hcldiags.Errs())
	}

	ep, diags := addrs.ParseMoveEndpoint(traversal)
	if diags.HasErrors() {
		panic(diags.Err())
	}

	return ep
}