package budget

import (
	"encoding/json"
	"os"
	"path/filepath"
	"reflect"
	"testing"
)

func TestWriteFiles(t *testing.T) {
	p := homePaths(t.TempDir())
	old := "old.scope.d/50-budget.conf"
	put(t, filepath.Join(p.units, old), "old")
	put(t, filepath.Join(p.units, "user.conf"), "keep")
	put(t, filepath.Join(p.state, "files.json"), `["old.scope.d/50-budget.conf"]`)
	files := map[string]string{"app-.scope.d/50-budget.conf": "[Scope]\nMemoryMax=8G\n", "search.slice": "[Slice]\n"}
	if err := writeFiles(p, files); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(filepath.Join(p.units, old)); !os.IsNotExist(err) {
		t.Fatalf("stale owned file remains: %v", err)
	}
	data, err := os.ReadFile(filepath.Join(p.units, "user.conf"))
	if err != nil || string(data) != "keep" {
		t.Fatal("unmanaged configuration changed")
	}
	data, err = os.ReadFile(filepath.Join(p.state, "files.json"))
	if err != nil {
		t.Fatal(err)
	}
	var manifest []string
	if err := json.Unmarshal(data, &manifest); err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(manifest, keys(files)) {
		t.Fatal(manifest)
	}
	for name, want := range files {
		data, err := os.ReadFile(filepath.Join(p.units, name))
		if err != nil || string(data) != want {
			t.Fatalf("%s: %q, %v", name, data, err)
		}
	}
	if err := writeFiles(p, files); err != nil {
		t.Fatal("second apply failed:", err)
	}
}

func TestFilesRetry(t *testing.T) {
	p := homePaths(t.TempDir())
	old := "old-a.scope.d/50-budget.conf"
	put(t, filepath.Join(p.units, old), "old")
	put(t, filepath.Join(p.state, "files.json"), `["old-a.scope.d/50-budget.conf", "old-b.scope.d/50-budget.conf"]`)
	blocker := filepath.Join(p.units, "new.scope.d")
	put(t, blocker, "blocked")
	files := map[string]string{"new.scope.d/50-budget.conf": "[Scope]\nMemoryMax=8G\n"}
	if err := writeFiles(p, files); err == nil {
		t.Fatal("write failure ignored")
	}
	if _, err := os.Stat(filepath.Join(p.units, old)); !os.IsNotExist(err) {
		t.Fatalf("cleanup did not finish before the write failure: %v", err)
	}
	if err := os.Remove(blocker); err != nil {
		t.Fatal(err)
	}
	if err := writeFiles(p, files); err != nil {
		t.Fatal("retry failed:", err)
	}
	data, err := os.ReadFile(filepath.Join(p.units, "new.scope.d/50-budget.conf"))
	if err != nil || string(data) != files["new.scope.d/50-budget.conf"] {
		t.Fatalf("replacement file: %q, %v", data, err)
	}
	data, err = os.ReadFile(filepath.Join(p.state, "files.json"))
	if err != nil {
		t.Fatal(err)
	}
	var manifest []string
	if err := json.Unmarshal(data, &manifest); err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(manifest, keys(files)) {
		t.Fatal("manifest was not updated:", manifest)
	}
}