package reply

import (
	"context"
	"encoding/json"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestCompleteSendsOpenAIRequestAndParsesReply(t *testing.T) {
	var (
		gotAuth    string
		gotSession string
		gotPath    string
		gotBody    chatRequest
	)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotAuth = r.Header.Get("Authorization")
		gotSession = r.Header.Get("x-opencode-session")
		gotPath = r.URL.Path
		if err := json.NewDecoder(r.Body).Decode(&gotBody); err != nil {
			t.Errorf("decode request: %v", err)
		}
		_ = json.NewEncoder(w).Encode(chatResponse{
			Model: "test-model",
			Choices: []struct {
				Message chatMessage `json:"message"`
			}{{Message: chatMessage{Role: "assistant", Content: "  Thanks, got it.  "}}},
		})
	}))
	defer srv.Close()

	c := NewClient(srv.URL, "secret-key", "auto/best-chat", slog.New(slog.DiscardHandler))
	if !c.Configured() {
		t.Fatal("client should be configured with a key")
	}
	got, err := c.Complete(context.Background(), "system prompt", "user prompt")
	if err != nil {
		t.Fatalf("Complete() error = %v", err)
	}
	if got != "Thanks, got it." {
		t.Errorf("Complete() = %q, want trimmed reply", got)
	}
	if gotPath != "/chat/completions" {
		t.Errorf("path = %q, want /chat/completions", gotPath)
	}
	if gotAuth != "Bearer secret-key" {
		t.Errorf("Authorization = %q", gotAuth)
	}
	if gotSession == "" {
		t.Error("x-opencode-session header was not set")
	}
	if gotBody.Model != "auto/best-chat" || gotBody.Stream {
		t.Errorf("request = %+v, want non-streaming auto/best-chat", gotBody)
	}
	if len(gotBody.Messages) != 2 || gotBody.Messages[0].Role != "system" || gotBody.Messages[1].Role != "user" {
		t.Errorf("messages = %+v", gotBody.Messages)
	}
}

func TestCompleteNotConfigured(t *testing.T) {
	c := NewClient("http://127.0.0.1:1/v1", "", "auto/best-chat", slog.New(slog.DiscardHandler))
	if c.Configured() {
		t.Fatal("client should not be configured without a key")
	}
	if _, err := c.Complete(context.Background(), "s", "u"); err != ErrNotConfigured {
		t.Fatalf("Complete() error = %v, want ErrNotConfigured", err)
	}
}

func TestCompleteReportsHTTPError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "nope", http.StatusUnauthorized)
	}))
	defer srv.Close()

	c := NewClient(srv.URL, "key", "m", slog.New(slog.DiscardHandler))
	_, err := c.Complete(context.Background(), "s", "u")
	if err == nil {
		t.Fatal("Complete() error = nil, want an error")
	}
}