package llm

import (
	"log/slog"
	"testing"
	"time"
)

func TestConfigValidate(t *testing.T) {
	tests := []struct {
		name    string
		cfg     Config
		wantErr bool
	}{
		{
			name:    "empty config",
			cfg:     Config{},
			wantErr: true,
		},
		{
			name:    "missing URL",
			cfg:     Config{},
			wantErr: true,
		},
		{
			name: "negative timeout",
			cfg: Config{
				URL:     "http://localhost:8080",
				Timeout: -time.Second,
			},
			wantErr: true,
		},
		{
			name: "valid minimal config",
			cfg: Config{
				URL: "http://localhost:8080",
			},
			wantErr: false,
		},
		{
			name: "valid config with timeout",
			cfg: Config{
				URL:     "http://localhost:8080",
				Timeout: 15 * time.Minute,
			},
			wantErr: false,
		},
		{
			name: "valid config with complex timeout",
			cfg: Config{
				URL:     "http://localhost:8080",
				Timeout: time.Hour + 30*time.Minute + 45*time.Second,
			},
			wantErr: false,
		},
		{
			name: "valid full config",
			cfg: Config{
				Key:     "sk-test-key",
				Timeout: 30 * time.Minute,
				URL:     "http://localhost:8080",
			},
			wantErr: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			err := tt.cfg.Validate()
			if (err != nil) != tt.wantErr {
				t.Errorf(
					"Validate() error = %v, wantErr %v",
					err, tt.wantErr,
				)
			}
		})
	}
}

func TestNewClient(t *testing.T) {
	log := slog.Default()
	tests := []struct {
		name    string
		cfg     Config
		log     *slog.Logger
		wantErr string
	}{
		{
			name:    "invalid config precedes nil logger",
			cfg:     Config{},
			wantErr: "invalid config: missing URL",
		},
		{
			name: "negative timeout precedes nil logger",
			cfg: Config{
				URL:     "http://localhost:8080",
				Timeout: -time.Second,
			},
			wantErr: "invalid config: invalid timeout -1s: must not be negative",
		},
		{
			name: "nil logger",
			cfg: Config{
				URL: "http://localhost:8080",
			},
			wantErr: "missing logger",
		},
		{
			name: "valid config without timeout",
			cfg: Config{
				URL: "http://localhost:8080",
			},
			log: log,
		},
		{
			name: "valid config with timeout",
			cfg: Config{
				URL:     "http://localhost:8080",
				Timeout: 10 * time.Minute,
			},
			log: log,
		},
		{
			name: "valid config with all fields",
			cfg: Config{
				Key:     "test-key",
				Timeout: 5 * time.Minute,
				URL:     "http://localhost:8080",
			},
			log: log,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			client, err := NewClient(tt.cfg, tt.log)
			if tt.wantErr != "" {
				if err == nil {
					t.Fatalf("NewClient() error = nil, want %q", tt.wantErr)
				}
				if err.Error() != tt.wantErr {
					t.Errorf(
						"NewClient() error = %q, want %q",
						err, tt.wantErr,
					)
				}
				if client != nil {
					t.Errorf("NewClient() client = %#v, want nil", client)
				}
				return
			}
			if err != nil {
				t.Fatalf("NewClient() error = %v, want nil", err)
			}
			if client == nil {
				t.Fatal("NewClient() client = nil, want non-nil")
			}
			wantTimeout := tt.cfg.Timeout
			if wantTimeout == 0 {
				wantTimeout = 5 * time.Minute
			}
			if client.timeout != wantTimeout {
				t.Errorf("timeout = %v, want %v", client.timeout, wantTimeout)
			}
		})
	}
}