package gsp

import (
	"os"
	"path/filepath"
	"testing"
)

func TestLoadValidateAndFlatten(t *testing.T) {
	root := t.TempDir()
	writeTestFile(t, root, "page.gsp", `id: page.lottery.main
type: page
resolution: L3
context: Lottery page.
with:
  - id: ui.button.primary
    context: Main action.
  - feedback.positive
refines: page.lottery.base
`)
	writeTestFile(t, root, "button.gsp", `id: ui.button.primary
type: ui
resolution: L3
context: Primary button.
`)
	writeTestFile(t, root, "feedback.gsp", `id: feedback.positive
type: feedback
resolution: L2
context: Positive feedback.
`)
	writeTestFile(t, root, "base.gsp", `id: page.lottery.base
resolution: L2
context: Base lottery page.
`)

	project, err := LoadProject(root)
	if err != nil {
		t.Fatal(err)
	}
	report := project.Validate("")
	if !report.OK {
		t.Fatalf("expected valid project, got errors: %+v", report.Errors)
	}

	flat := project.Flatten("page.lottery.main", -1, Filter{})
	got := ids(flat.Units)
	want := []string{"page.lottery.main", "page.lottery.base", "feedback.positive", "ui.button.primary"}
	if !sameStrings(got, want) {
		t.Fatalf("flatten ids = %v, want %v", got, want)
	}
}

func TestValidateMissingReference(t *testing.T) {
	root := t.TempDir()
	writeTestFile(t, root, "page.gsp", `id: page.missing
with:
  - ui.missing
`)
	project, err := LoadProject(root)
	if err != nil {
		t.Fatal(err)
	}
	report := project.Validate("")
	if report.OK {
		t.Fatal("expected validation failure")
	}
	found := false
	for _, issue := range report.Errors {
		if issue.Code == "missing_with" {
			found = true
		}
	}
	if !found {
		t.Fatalf("expected missing_with error, got %+v", report.Errors)
	}
}

func TestStageCheck(t *testing.T) {
	root := t.TempDir()
	writeTestFile(t, root, "page.gsp", `id: page.low
resolution: L2
`)
	project, err := LoadProject(root)
	if err != nil {
		t.Fatal(err)
	}
	report := project.StageCheck("implement")
	if report.OK {
		t.Fatal("expected implement stage check to fail")
	}
	if report.Errors[0].Code != "low_resolution" {
		t.Fatalf("expected low_resolution, got %+v", report.Errors)
	}
}

func writeTestFile(t *testing.T, root, name, content string) {
	t.Helper()
	path := filepath.Join(root, name)
	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
		t.Fatal(err)
	}
}

func ids(units []*Unit) []string {
	out := make([]string, 0, len(units))
	for _, unit := range units {
		out = append(out, unit.ID)
	}
	return out
}

func sameStrings(a, b []string) bool {
	if len(a) != len(b) {
		return false
	}
	for i := range a {
		if a[i] != b[i] {
			return false
		}
	}
	return true
}