package main

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

// A catalogue whose dunst falls back to font-size, and the trunk's list holding font-size and
// agent-managed-settings.
func aCatalogue(t *testing.T, list string) (root, base string) {
	t.Helper()
	root = t.TempDir()
	write := func(path, text string) {
		t.Helper()
		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(path, []byte(text), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	write(filepath.Join(root, "modules", "dunst", "module.json"), `{"module": "dunst", "config": {"font-size":
	  {"type": "number", "description": "points", "default": 10, "predefined": "font-size"}}}`)
	write(filepath.Join(root, "modules", "claude-code", "module.json"), `{"module": "claude-code", "settings": {
	  "managed_settings": {"kind": "preference", "default": "{}", "why": "none"}}}`)
	write(filepath.Join(root, "modules", "plain", "module.json"), `{"module": "plain"}`)
	if list != "" {
		write(filepath.Join(root, File), list)
	}
	base = filepath.Join(t.TempDir(), "base.json")
	write(base, `{"font-size": {"type": "number"}, "agent-managed-settings": {"type": "object"}}`)
	return root, base
}

func run(t *testing.T, args ...string) (string, error) {
	t.Helper()
	out, err := exec.Command("go", append([]string{"run", "."}, args...)...).CombinedOutput()
	return string(out), err
}

func TestARemovalOfAKeyAModuleStillNamesIsRefused(t *testing.T) {
	// The planted removal: font-size goes while dunst still falls back to it.
	root, base := aCatalogue(t, `{"agent-managed-settings": {"type": "object"}}`)
	out, err := run(t, "-base", base, root)
	if err == nil || !strings.Contains(out, `the key "font-size" is removed and still named by dunst`) {
		t.Fatalf("a removal of a named key passed:\n%s", out)
	}
}

func TestARemovalNobodyNamesPassesAndSaysWhatItCannotKnow(t *testing.T) {
	root, base := aCatalogue(t, `{"font-size": {"type": "number"}}`)
	out, err := run(t, "-base", base, root)
	if err != nil || !strings.Contains(out, `"agent-managed-settings" is removed and no module names it`) ||
		!strings.Contains(out, "mesh-config's to refuse") {
		t.Fatalf("a removal nobody names: %v\n%s", err, out)
	}
}

func TestAListUnchangedOrGrownPasses(t *testing.T) {
	for _, list := range []string{
		`{"font-size": {"type": "number"}, "agent-managed-settings": {"type": "object"}}`,
		`{"font-size": {"type": "number"}, "agent-managed-settings": {"type": "object"}, "accent": {"type": "string"}}`,
	} {
		root, base := aCatalogue(t, list)
		if out, err := run(t, "-base", base, root); err != nil || !strings.Contains(out, "none removed") {
			t.Fatalf("%s: %v\n%s", list, err, out)
		}
	}
	// No trunk list given: nothing was removed.
	root, _ := aCatalogue(t, `{}`)
	if out, err := run(t, root); err != nil || !strings.Contains(out, "none was removed") {
		t.Fatalf("without a base: %v\n%s", err, out)
	}
}

func TestTheFileRemovedWholeIsARemovalOfEveryKey(t *testing.T) {
	root, base := aCatalogue(t, "")
	out, err := run(t, "-base", base, root)
	if err == nil || !strings.Contains(out, `"font-size" is removed and still named by dunst`) {
		t.Fatalf("the list removed whole passed:\n%s", out)
	}
}

func TestNamedReadsBothForms(t *testing.T) {
	root, _ := aCatalogue(t, "")
	if err := os.WriteFile(filepath.Join(root, "modules", "plain", "module.json"), []byte(`{"module": "plain",
	  "settings": {"size": {"predefined": "font-size"}}}`), 0o644); err != nil {
		t.Fatal(err)
	}
	named, err := Named(root)
	if err != nil {
		t.Fatal(err)
	}
	if got := strings.Join(named["font-size"], ","); got != "dunst,plain" {
		t.Fatalf("font-size named by %s", got)
	}
}