package cliamp

import "testing"

func TestMergeSection_AppendWhenAbsent(t *testing.T) {
	existing := "[plex]\nurl = \"http://plex\"\ntoken = \"abc\"\n"
	block := Creds{URL: "http://jf", Token: "tok", UserID: "uid"}.block()
	got := mergeSection(existing, "jellyfin", block)

	// The plex section must survive untouched.
	if !contains(got, "[plex]") || !contains(got, `url = "http://plex"`) || !contains(got, `token = "abc"`) {
		t.Fatalf("plex section not preserved:\n%s", got)
	}
	// The jellyfin section must be appended.
	if !contains(got, "[jellyfin]") || !contains(got, `token = "tok"`) || !contains(got, `user_id = "uid"`) {
		t.Fatalf("jellyfin section not appended:\n%s", got)
	}
}

func TestMergeSection_ReplaceExisting(t *testing.T) {
	existing := "[jellyfin]\nurl = \"old\"\ntoken = \"OLD\"\n\n[spotify]\nclient = \"sp\"\n"
	block := Creds{URL: "http://new", Token: "NEW", UserID: "uid"}.block()
	got := mergeSection(existing, "jellyfin", block)

	if contains(got, `token = "OLD"`) || contains(got, `url = "old"`) {
		t.Fatalf("old jellyfin values not replaced:\n%s", got)
	}
	if !contains(got, `token = "NEW"`) || !contains(got, `url = "http://new"`) {
		t.Fatalf("new jellyfin values missing:\n%s", got)
	}
	// The spotify section after jellyfin must survive.
	if !contains(got, "[spotify]") || !contains(got, `client = "sp"`) {
		t.Fatalf("spotify section not preserved:\n%s", got)
	}
}

func TestMergeSection_EmptyDoc(t *testing.T) {
	block := Creds{URL: "http://jf", Token: "tok", UserID: "uid"}.block()
	got := mergeSection("", "jellyfin", block)
	if got != block+"\n" {
		t.Fatalf("empty-doc merge wrong:\n%q", got)
	}
}

func TestBlock_OmitsEmptyFields(t *testing.T) {
	got := Creds{URL: "http://jf", Token: "tok", UserID: "uid"}.block()
	if contains(got, "user =") || contains(got, "password =") {
		t.Fatalf("empty user/password should be omitted:\n%s", got)
	}
}

func contains(haystack, needle string) bool {
	return len(haystack) >= len(needle) && indexOf(haystack, needle) >= 0
}

func indexOf(s, sub string) int {
	for i := 0; i+len(sub) <= len(s); i++ {
		if s[i:i+len(sub)] == sub {
			return i
		}
	}
	return -1
}