package campaign

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

func writeFile(t *testing.T, path, content string) {
	t.Helper()
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}
}

func TestParseFile_ParsesFrontmatterAndBody(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, `---
subject: "Big Announcement"
lists: ["Newsletter"]
from_email: hello@reground.org
tags: ["announcement"]
attachments:
  - assets/one-pager.pdf
---
Hello **world**.
`)

	fm, body, err := ParseFile(path)
	if err != nil {
		t.Fatalf("ParseFile: %v", err)
	}
	if fm.Subject != "Big Announcement" {
		t.Errorf("unexpected subject: %q", fm.Subject)
	}
	if len(fm.Lists) != 1 || fm.Lists[0] != "Newsletter" {
		t.Errorf("unexpected lists: %v", fm.Lists)
	}
	if fm.Type != "regular" {
		t.Errorf("expected type to default to regular, got %q", fm.Type)
	}
	if !strings.Contains(body, "Hello **world**.") {
		t.Errorf("unexpected body: %q", body)
	}
}

func TestParseFile_MissingFrontmatterDelimiter(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, "no frontmatter here\n")

	if _, _, err := ParseFile(path); err == nil {
		t.Fatal("expected an error for a file with no frontmatter block")
	}
}

func TestParseFile_UnterminatedFrontmatter(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, "---\nsubject: hi\nbody with no closing delimiter")

	if _, _, err := ParseFile(path); err == nil {
		t.Fatal("expected an error for unterminated frontmatter")
	}
}

func TestParseFile_MissingSubject(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, `---
lists: ["Newsletter"]
from_email: hello@reground.org
---
body
`)
	if _, _, err := ParseFile(path); err == nil || !strings.Contains(err.Error(), "subject") {
		t.Fatalf("expected a 'missing subject' error, got %v", err)
	}
}

func TestParseFile_MissingFromEmail(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, `---
subject: hi
lists: ["Newsletter"]
---
body
`)
	if _, _, err := ParseFile(path); err == nil || !strings.Contains(err.Error(), "from_email") {
		t.Fatalf("expected a 'missing from_email' error, got %v", err)
	}
}

func TestParseFile_RequiresListsOrSegmentQuery(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, `---
subject: hi
from_email: hello@reground.org
---
body
`)
	if _, _, err := ParseFile(path); err == nil || !strings.Contains(err.Error(), "target audience") {
		t.Fatalf("expected a 'needs a target audience' error, got %v", err)
	}
}

func TestParseFile_SegmentQueryAloneSatisfiesTargetAudience(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, `---
subject: hi
from_email: hello@reground.org
segment_query: "subscribers.attribs->>'source' = 'workshop'"
---
body
`)
	if _, _, err := ParseFile(path); err != nil {
		t.Fatalf("expected segment_query alone to be sufficient, got %v", err)
	}
}

func TestParseFile_RejectsOptin(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, `---
subject: hi
lists: ["Newsletter"]
from_email: hello@reground.org
type: optin
---
body
`)
	if _, _, err := ParseFile(path); err == nil || !strings.Contains(err.Error(), "optin") {
		t.Fatalf("expected an 'optin not supported' error, got %v", err)
	}
}

func TestParseFile_MalformedYAML(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "campaign.md")
	writeFile(t, path, "---\nsubject: [unterminated\n---\nbody\n")

	if _, _, err := ParseFile(path); err == nil {
		t.Fatal("expected an error for malformed YAML frontmatter")
	}
}