package ai

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/cloudwego/eino/schema"
)

func TestResolveOpenAIBaseURL(t *testing.T) {
	tests := []struct {
		name     string
		baseURL  string
		endpoint string
		want     string
		wantErr  bool
	}{
		{name: "base url", baseURL: "https://xueyangai.com/v1/", want: "https://xueyangai.com/v1"},
		{name: "legacy endpoint", endpoint: "https://xueyangai.com/v1/chat/completions", want: "https://xueyangai.com/v1"},
		{name: "base url preferred", baseURL: "https://example.com/v1", endpoint: "https://legacy.example.com/v1/chat/completions", want: "https://example.com/v1"},
		{name: "invalid", baseURL: "xueyangai.com/v1", wantErr: true},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			got, err := ResolveOpenAIBaseURL(test.baseURL, test.endpoint)
			if test.wantErr {
				if err == nil {
					t.Fatal("expected error")
				}
				return
			}
			if err != nil {
				t.Fatalf("ResolveOpenAIBaseURL() error = %v", err)
			}
			if got != test.want {
				t.Fatalf("ResolveOpenAIBaseURL() = %s, want %s", got, test.want)
			}
		})
	}
}

func TestOpenAICompatibleChatModel(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
		if request.URL.Path != "/v1/chat/completions" {
			t.Errorf("path = %s, want /v1/chat/completions", request.URL.Path)
		}
		if request.Header.Get("Authorization") != "Bearer test-key" {
			t.Errorf("authorization = %s", request.Header.Get("Authorization"))
		}
		var body map[string]any
		if err := json.NewDecoder(request.Body).Decode(&body); err != nil {
			t.Errorf("decode request: %v", err)
		}
		if body["model"] != "test-model" {
			t.Errorf("model = %v, want test-model", body["model"])
		}
		writer.Header().Set("Content-Type", "application/json")
		_, _ = writer.Write([]byte(`{"id":"chatcmpl-test","object":"chat.completion","created":1,"model":"test-model","choices":[{"index":0,"message":{"role":"assistant","content":"{\"ok\":true}"},"finish_reason":"stop"}],"usage":{"prompt_tokens":1,"completion_tokens":1,"total_tokens":2}}`))
	}))
	defer server.Close()

	chatModel, err := NewOpenAICompatibleChatModel(context.Background(), OpenAICompatibleConfig{
		APIKey:     "test-key",
		BaseURL:    server.URL + "/v1",
		Model:      "test-model",
		Timeout:    3 * time.Second,
		MaxTokens:  64,
		JSONOutput: true,
	})
	if err != nil {
		t.Fatalf("NewOpenAICompatibleChatModel() error = %v", err)
	}
	response, err := chatModel.Generate(context.Background(), []*schema.Message{schema.UserMessage("hello")})
	if err != nil {
		t.Fatalf("Generate() error = %v", err)
	}
	if response.Content != `{"ok":true}` {
		t.Fatalf("response content = %s", response.Content)
	}
}

func TestNewChatModelRejectsUnsupportedProvider(t *testing.T) {
	_, err := NewChatModel(context.Background(), ChatModelConfig{Provider: "unsupported"})
	if err == nil {
		t.Fatal("expected unsupported provider error")
	}
}