package configs

import (
	"testing"

	"github.com/google/go-cmp/cmp"
	"github.com/hashicorp/hcl/v2"

	"github.com/hashicorp/terraform/internal/experiments"
)

func TestExperimentsConfig(t *testing.T) {
	// The experiment registrations are global, so we need to do some special
	// patching in order to get a predictable set for our tests.
	current := experiments.Experiment("current")
	concluded := experiments.Experiment("concluded")
	currentExperiments := experiments.NewSet(current)
	concludedExperiments := map[experiments.Experiment]string{
		concluded: "Reticulate your splines.",
	}
	defer experiments.OverrideForTesting(t, currentExperiments, concludedExperiments)()

	t.Run("current", func(t *testing.T) {
		parser := NewParser(nil)
		parser.AllowLanguageExperiments(true)
		mod, diags := parser.LoadConfigDir("testdata/experiments/current")
		if got, want := len(diags), 1; got != want {
			t.Fatalf("wrong number of diagnostics %d; want %d", got, want)
		}
		got := diags[0]
		want := &hcl.Diagnostic{
			Severity: hcl.DiagWarning,
			Summary:  `Experimental feature "current" is active`,
			Detail:   "Experimental features are available only in alpha releases of Terraform and are subject to breaking changes or total removal in later versions, based on feedback. We recommend against using experimental features in production.\n\nIf you have feedback on the design of this feature, please open a GitHub issue to discuss it.",
			Subject: &hcl.Range{
				Filename: "testdata/experiments/current/current_experiment.tf",
				Start:    hcl.Pos{Line: 2, Column: 18, Byte: 29},
				End:      hcl.Pos{Line: 2, Column: 25, Byte: 36},
			},
		}
		if diff := cmp.Diff(want, got); diff != "" {
			t.Errorf("wrong warning\n%s", diff)
		}
		if got, want := len(mod.ActiveExperiments), 1; got != want {
			t.Errorf("wrong number of experiments %d; want %d", got, want)
		}
		if !mod.ActiveExperiments.Has(current) {
			t.Errorf("module does not indicate current experiment as active")
		}
	})
	t.Run("concluded", func(t *testing.T) {
		parser := NewParser(nil)
		parser.AllowLanguageExperiments(true)
		_, diags := parser.LoadConfigDir("testdata/experiments/concluded")
		if got, want := len(diags), 1; got != want {
			t.Fatalf("wrong number of diagnostics %d; want %d", got, want)
		}
		got := diags[0]
		want := &hcl.Diagnostic{
			Severity: hcl.DiagError,
			Summary:  `Experiment has concluded`,
			Detail:   `Experiment "concluded" is no longer available. Reticulate your splines.`,
			Subject: &hcl.Range{
				Filename: "testdata/experiments/concluded/concluded_experiment.tf",
				Start:    hcl.Pos{Line: 2, Column: 18, Byte: 29},
				End:      hcl.Pos{Line: 2, Column: 27, Byte: 38},
			},
		}
		if diff := cmp.Diff(want, got); diff != "" {
			t.Errorf("wrong error\n%s", diff)
		}
	})
	t.Run("concluded", func(t *testing.T) {
		parser := NewParser(nil)
		parser.AllowLanguageExperiments(true)
		_, diags := parser.LoadConfigDir("testdata/experiments/unknown")
		if got, want := len(diags), 1; got != want {
			t.Fatalf("wrong number of diagnostics %d; want %d", got, want)
		}
		got := diags[0]
		want := &hcl.Diagnostic{
			Severity: hcl.DiagError,
			Summary:  `Unknown experiment keyword`,
			Detail:   `There is no current experiment with the keyword "unknown".`,
			Subject: &hcl.Range{
				Filename: "testdata/experiments/unknown/unknown_experiment.tf",
				Start:    hcl.Pos{Line: 2, Column: 18, Byte: 29},
				End:      hcl.Pos{Line: 2, Column: 25, Byte: 36},
			},
		}
		if diff := cmp.Diff(want, got); diff != "" {
			t.Errorf("wrong error\n%s", diff)
		}
	})
	t.Run("invalid", func(t *testing.T) {
		parser := NewParser(nil)
		parser.AllowLanguageExperiments(true)
		_, diags := parser.LoadConfigDir("testdata/experiments/invalid")
		if got, want := len(diags), 1; got != want {
			t.Fatalf("wrong number of diagnostics %d; want %d", got, want)
		}
		got := diags[0]
		want := &hcl.Diagnostic{
			Severity: hcl.DiagError,
			Summary:  `Invalid expression`,
			Detail:   `A static list expression is required.`,
			Subject: &hcl.Range{
				Filename: "testdata/experiments/invalid/invalid_experiments.tf",
				Start:    hcl.Pos{Line: 2, Column: 17, Byte: 28},
				End:      hcl.Pos{Line: 2, Column: 24, Byte: 35},
			},
		}
		if diff := cmp.Diff(want, got); diff != "" {
			t.Errorf("wrong error\n%s", diff)
		}
	})
	t.Run("disallowed", func(t *testing.T) {
		parser := NewParser(nil)
		parser.AllowLanguageExperiments(false) // The default situation for release builds
		_, diags := parser.LoadConfigDir("testdata/experiments/current")
		if got, want := len(diags), 1; got != want {
			t.Fatalf("wrong number of diagnostics %d; want %d", got, want)
		}
		got := diags[0]
		want := &hcl.Diagnostic{
			Severity: hcl.DiagError,
			Summary:  `Module uses experimental features`,
			Detail:   `Experimental features are intended only for gathering early feedback on new language designs, and so are available only in alpha releases of Terraform.`,
			Subject: &hcl.Range{
				Filename: "testdata/experiments/current/current_experiment.tf",
				Start:    hcl.Pos{Line: 2, Column: 3, Byte: 14},
				End:      hcl.Pos{Line: 2, Column: 14, Byte: 25},
			},
		}
		if diff := cmp.Diff(want, got); diff != "" {
			t.Errorf("wrong error\n%s", diff)
		}
	})
}