package configgen

import (
	"strings"
	"testing"

	"gitea.dooplex.hu/admin/felhom-hub/internal/store"
)

// S4/S6 (R-558) — `customer.language` reaches controller.yaml, and it is the ONLY thing that moved.
//
// The controller reads it to decide what language a box STARTS in, before anyone has touched the
// dashboard switch. It has to arrive, and nothing else may arrive with it: a config pull restarts
// the box, so an unintended second change would ride out to the whole fleet on the same wire.
func TestGenerate_CustomerLanguage(t *testing.T) {
	const tmpl = "customer:\n  id: \"\"\n  name: \"\"\nlogging:\n  level: info\n"

	base := &store.CustomerConfig{CustomerID: "c1", CustomerName: "Acme", ConfigJSON: "{}"}
	withEN := &store.CustomerConfig{CustomerID: "c1", CustomerName: "Acme", ConfigJSON: "{}", Language: "en"}

	huYAML, err := Generate(tmpl, base, nil)
	if err != nil {
		t.Fatal(err)
	}
	enYAML, err := Generate(tmpl, withEN, nil)
	if err != nil {
		t.Fatal(err)
	}

	if !strings.Contains(enYAML, "language: en") {
		t.Fatalf("customer.language did not reach controller.yaml:\n%s", enYAML)
	}

	// THE DIFF IS EXACTLY ONE LINE. Compared line by line after dropping the fields that are
	// regenerated on every call — a session secret and a timestamp differ between any two renders,
	// so counting them would make this test pass no matter what else changed.
	huLines := stableLines(huYAML)
	enLines := stableLines(enYAML)
	var onlyInEN, onlyInHU []string
	for _, l := range enLines {
		if !contains(huLines, l) {
			onlyInEN = append(onlyInEN, l)
		}
	}
	for _, l := range huLines {
		if !contains(enLines, l) {
			onlyInHU = append(onlyInHU, l)
		}
	}
	if len(onlyInEN) != 1 || !strings.Contains(onlyInEN[0], "language: en") {
		t.Errorf("the English config differs from the Hungarian one by %d line(s), want exactly the "+
			"language line: %v", len(onlyInEN), onlyInEN)
	}
	if len(onlyInHU) != 1 || !strings.Contains(onlyInHU[0], "language:") {
		t.Errorf("the Hungarian config has %d line(s) the English one lacks, want exactly the "+
			"language line: %v", len(onlyInHU), onlyInHU)
	}
}

// An empty creation language still writes a line — the box is told "Hungarian" explicitly rather
// than being left to guess from an absent key.
func TestGenerate_EmptyLanguageStillWritesTheKey(t *testing.T) {
	const tmpl = "customer:\n  id: \"\"\n"
	y, err := Generate(tmpl, &store.CustomerConfig{CustomerID: "c1", ConfigJSON: "{}"}, nil)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(y, "language:") {
		t.Errorf("no language key at all — the box cannot tell a default from a missing field:\n%s", y)
	}
}

// stableLines drops the lines that are regenerated on every call, so two renders are comparable.
func stableLines(y string) []string {
	var out []string
	for _, l := range strings.Split(y, "\n") {
		t := strings.TrimSpace(l)
		if t == "" || strings.HasPrefix(t, "session_secret:") || strings.HasPrefix(t, "generated_at:") {
			continue
		}
		out = append(out, l)
	}
	return out
}

func contains(ls []string, want string) bool {
	for _, l := range ls {
		if l == want {
			return true
		}
	}
	return false
}