package config

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

func TestLoadConfig_Valid(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
server:
  host: "127.0.0.1"
  port: 9090
  username: "testuser"
  password: "testpass"

navidrome:
  url: "http://navidrome:4533"
  user: "service"
  password: "secret"

musicbrainz:
  user_agent: "NaviWatcher/1.0 ( test@example.com )"
  cache_ttl: 24h

telegram:
  enabled: true
  token: "abc123"
  chat_id: "chat456"
  cron_schedule: "0 10 * * *"

scanner:
  fuzzy_threshold: 0.9
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

	cfg, err := LoadConfig(path)
	if err != nil {
		t.Fatalf("LoadConfig returned error: %v", err)
	}

	if cfg.Server.Host != "127.0.0.1" {
		t.Errorf("expected host 127.0.0.1, got %s", cfg.Server.Host)
	}
	if cfg.Server.Port != 9090 {
		t.Errorf("expected port 9090, got %d", cfg.Server.Port)
	}
	if cfg.Server.Username != "testuser" {
		t.Errorf("expected username testuser, got %s", cfg.Server.Username)
	}
	if cfg.Navidrome.URL != "http://navidrome:4533" {
		t.Errorf("expected navidrome url http://navidrome:4533, got %s", cfg.Navidrome.URL)
	}
	if cfg.Telegram.ChatID != "chat456" {
		t.Errorf("expected telegram chat_id chat456, got %s", cfg.Telegram.ChatID)
	}
	if cfg.Navidrome.User != "service" {
		t.Errorf("expected navidrome user service, got %s", cfg.Navidrome.User)
	}
	if cfg.Scanner.FuzzyThreshold != 0.9 {
		t.Errorf("expected fuzzy_threshold 0.9, got %f", cfg.Scanner.FuzzyThreshold)
	}
}

func TestLoadConfig_Defaults(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
navidrome:
  url: "http://localhost:4533"
  user: "u"
  password: "p"

musicbrainz:
  user_agent: "NaviWatcher/1.0 ( test@example.com )"
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

	cfg, err := LoadConfig(path)
	if err != nil {
		t.Fatalf("LoadConfig returned error: %v", err)
	}

	if cfg.Server.Host != "0.0.0.0" {
		t.Errorf("expected default host 0.0.0.0, got %s", cfg.Server.Host)
	}
	if cfg.Server.Port != 8080 {
		t.Errorf("expected default port 8080, got %d", cfg.Server.Port)
	}
	if cfg.Scanner.FuzzyThreshold != 0.85 {
		t.Errorf("expected default fuzzy_threshold 0.85, got %f", cfg.Scanner.FuzzyThreshold)
	}
}

func TestLoadConfig_MissingFile(t *testing.T) {
	_, err := LoadConfig("/nonexistent/path/config.yaml")
	if err == nil {
		t.Fatal("expected error for missing file, got nil")
	}
}

func TestLoadConfig_MalformedYAML(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
server:
  host: [invalid
  yaml: {broken
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

	_, err := LoadConfig(path)
	if err == nil {
		t.Fatal("expected error for malformed YAML, got nil")
	}
}

func TestLoadConfig_InvalidPort(t *testing.T) {
	tests := []struct {
		name string
		port int
	}{
		{"port too high", 70000},
		{"port negative", -1},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			dir := t.TempDir()
			path := filepath.Join(dir, "config.yaml")

			yaml := buildConfigWithPort(tt.port)
			if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
				t.Fatalf("failed to write config: %v", err)
			}

			_, err := LoadConfig(path)
			if err == nil {
				t.Fatalf("expected error for port %d, got nil", tt.port)
			}
		})
	}
}

func buildConfigWithPort(port int) string {
	return "navidrome:\n  url: \"http://localhost:4533\"\n  user: \"u\"\n  password: \"p\"\n\nmusicbrainz:\n  user_agent: \"NaviWatcher/1.0 ( test@example.com )\"\n\nserver:\n  port: " + fmt.Sprintf("%d", port) + "\n"
}

func TestLoadConfig_InvalidThreshold(t *testing.T) {
	tests := []struct {
		name      string
		threshold float64
	}{
		{"threshold too high", 1.5},
		{"threshold negative", -0.1},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			dir := t.TempDir()
			path := filepath.Join(dir, "config.yaml")

			yaml := "navidrome:\n  url: \"http://localhost:4533\"\n  user: \"u\"\n  password: \"p\"\n\nmusicbrainz:\n  user_agent: \"NaviWatcher/1.0 ( test@example.com )\"\n\nscanner:\n  fuzzy_threshold: " + fmt.Sprintf("%.1f", tt.threshold) + "\n"
			if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
				t.Fatalf("failed to write config: %v", err)
			}

			_, err := LoadConfig(path)
			if err == nil {
				t.Fatalf("expected error for threshold %f, got nil", tt.threshold)
			}
		})
	}
}

func TestValidate_MissingNavidromeURL(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
navidrome:
  user: "u"
  password: "p"

musicbrainz:
  user_agent: "NaviWatcher/1.0 ( test@example.com )"
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

	_, err := LoadConfig(path)
	if err == nil {
		t.Fatal("expected error for missing navidrome.url, got nil")
	}
}

func TestValidate_MissingNavidromeUser(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
navidrome:
  url: "http://localhost:4533"
  password: "p"

musicbrainz:
  user_agent: "NaviWatcher/1.0 ( test@example.com )"
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

	_, err := LoadConfig(path)
	if err == nil {
		t.Fatal("expected error for missing navidrome.user, got nil")
	}
}

func TestValidate_MissingNavidromePassword(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
navidrome:
  url: "http://localhost:4533"
  user: "u"

musicbrainz:
  user_agent: "NaviWatcher/1.0 ( test@example.com )"
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

	_, err := LoadConfig(path)
	if err == nil {
		t.Fatal("expected error for missing navidrome.password, got nil")
	}
}

func TestValidate_MissingMusicBrainzUserAgent(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
navidrome:
  url: "http://localhost:4533"
  user: "u"
  password: "p"

musicbrainz:
  cache_ttl: 24h
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatalf("failed to write config: %v", err)
	}

	_, err := LoadConfig(path)
	if err == nil {
		t.Fatal("expected error for missing musicbrainz.user_agent, got nil")
	}
}

func TestValidate_BoundaryThreshold(t *testing.T) {
	tests := []struct {
		name      string
		threshold float64
		wantErr   bool
	}{
		{"threshold 0.0", 0.0, false},
		{"threshold 1.0", 1.0, false},
		{"threshold 0.5", 0.5, false},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			dir := t.TempDir()
			path := filepath.Join(dir, "config.yaml")

			yaml := "navidrome:\n  url: \"http://localhost:4533\"\n  user: \"u\"\n  password: \"p\"\n\nmusicbrainz:\n  user_agent: \"NaviWatcher/1.0 ( test@example.com )\"\n\nscanner:\n  fuzzy_threshold: " + fmt.Sprintf("%.2f", tt.threshold) + "\n"
			if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
				t.Fatalf("failed to write config: %v", err)
			}

			_, err := LoadConfig(path)
			if tt.wantErr && err == nil {
				t.Fatalf("expected error for threshold %f, got nil", tt.threshold)
			}
			if !tt.wantErr && err != nil {
				t.Fatalf("unexpected error for threshold %f: %v", tt.threshold, err)
			}
		})
	}
}

func TestValidate_BoundaryPort(t *testing.T) {
	tests := []struct {
		name    string
		port    int
		wantErr bool
	}{
		{"port 1", 1, false},
		{"port 65535", 65535, false},
		{"port 8080", 8080, false},
		{"port 65536", 65536, true},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			dir := t.TempDir()
			path := filepath.Join(dir, "config.yaml")

			yaml := buildConfigWithPort(tt.port)
			if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
				t.Fatalf("failed to write config: %v", err)
			}

			_, err := LoadConfig(path)
			if tt.wantErr && err == nil {
				t.Fatalf("expected error for port %d, got nil", tt.port)
			}
			if !tt.wantErr && err != nil {
				t.Fatalf("unexpected error for port %d: %v", tt.port, err)
			}
		})
	}
}