//go:build linux || freebsd

package storage

import (
	"bufio"
	"encoding/json"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestNewsletterStore_AppendCreatesFile(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "subs", "subscribers.jsonl")
	s := NewNewsletterStore(path)

	if err := s.Append(Subscriber{Email: "a@example.com", Form: "newsletter"}); err != nil {
		t.Fatalf("Append: %v", err)
	}

	if _, err := os.Stat(path); err != nil {
		t.Fatalf("expected file to exist, got %v", err)
	}
}

func TestNewsletterStore_AppendAndCount(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "subs.jsonl")
	s := NewNewsletterStore(path)

	for i, e := range []string{"a@x.com", "b@x.com", "c@x.com"} {
		if err := s.Append(Subscriber{Email: e, Form: "newsletter"}); err != nil {
			t.Fatalf("Append #%d: %v", i, err)
		}
	}

	n, err := s.Count()
	if err != nil {
		t.Fatalf("Count: %v", err)
	}
	if n != 3 {
		t.Errorf("expected 3 subscribers, got %d", n)
	}
}

func TestNewsletterStore_AppendIsOneLinePerRecord(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "subs.jsonl")
	s := NewNewsletterStore(path)

	for _, e := range []string{"a@x.com", "b@x.com"} {
		if err := s.Append(Subscriber{Email: e, Form: "n"}); err != nil {
			t.Fatalf("Append: %v", err)
		}
	}

	// Each line should be a self-contained JSON object.
	data, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("ReadFile: %v", err)
	}
	scanner := bufio.NewScanner(strings.NewReader(string(data)))
	count := 0
	for scanner.Scan() {
		line := scanner.Bytes()
		if len(line) == 0 {
			continue
		}
		var sub Subscriber
		if err := json.Unmarshal(line, &sub); err != nil {
			t.Fatalf("Unmarshal line: %v", err)
		}
		count++
	}
	if err := scanner.Err(); err != nil {
		t.Fatalf("scanner.Err: %v", err)
	}
	if count != 2 {
		t.Errorf("expected 2 records, decoded %d", count)
	}
}

func TestNewsletterStore_CountOnMissingFileIsZero(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "does-not-exist.jsonl")
	s := NewNewsletterStore(path)

	n, err := s.Count()
	if err != nil {
		t.Fatalf("Count on missing file: %v", err)
	}
	if n != 0 {
		t.Errorf("expected 0 on missing file, got %d", n)
	}
}

func TestNewsletterStore_ListReturnsInsertionOrder(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "subs.jsonl")
	s := NewNewsletterStore(path)

	want := []string{"a@x.com", "b@x.com", "c@x.com"}
	for _, e := range want {
		_ = s.Append(Subscriber{Email: e, Form: "n"})
	}

	subs, err := s.List()
	if err != nil {
		t.Fatalf("List: %v", err)
	}
	if len(subs) != len(want) {
		t.Fatalf("expected %d, got %d", len(want), len(subs))
	}
	for i, sub := range subs {
		if sub.Email != want[i] {
			t.Errorf("position %d: want %q, got %q", i, want[i], sub.Email)
		}
	}
}

func TestNewsletterStore_SkipsMalformedLines(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "subs.jsonl")

	// Write a mix of valid and garbage lines.
	content := `{"email":"good1@x.com","form":"n","created_at":"2026-01-01T00:00:00Z"}
this is not valid json
{"email":"good2@x.com","form":"n","created_at":"2026-01-02T00:00:00Z"}
{not even close to json
`
	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
		t.Fatalf("WriteFile: %v", err)
	}

	s := NewNewsletterStore(path)
	n, err := s.Count()
	if err != nil {
		t.Fatalf("Count: %v", err)
	}
	if n != 2 {
		t.Errorf("expected 2 valid records (skipping malformed), got %d", n)
	}
}

func TestNewsletterStore_PathReturnsConfiguredPath(t *testing.T) {
	path := filepath.Join(t.TempDir(), "subs.jsonl")
	s := NewNewsletterStore(path)
	if got := s.Path(); got != path {
		t.Errorf("Path: want %q, got %q", path, got)
	}
}