package deepseek

import (
	"context"
	"io"
	"net/http"
	"strings"
	"testing"
)

type roundTripFunc func(*http.Request) (*http.Response, error)

func (f roundTripFunc) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }

func testAPI(handler roundTripFunc) *Client {
	return NewClient().
		SetBaseURL("https://api.example.test").
		SetHTTPClient(&http.Client{Transport: handler})
}

func testHTTPResponse(body string) *http.Response {
	return &http.Response{
		StatusCode: http.StatusOK,
		Status:     "200 OK",
		Header:     make(http.Header),
		Body:       io.NopCloser(strings.NewReader(body)),
	}
}

func TestRequestUnmarshallBizResponse(t *testing.T) {
	tests := []struct {
		name      string
		body      string
		wantValue string
		wantErr   string
	}{
		{name: "success", body: `{"code":0,"data":{"biz_code":0,"biz_data":{"value":"ok"}}}`, wantValue: "ok"},
		{name: "outer error", body: `{"code":401,"msg":"unauthorized"}`, wantErr: "unauthorized (401)"},
		{name: "business error", body: `{"code":0,"data":{"biz_code":23,"biz_msg":"denied"}}`, wantErr: "denied (23)"},
		{name: "invalid JSON", body: `{`, wantErr: "unexpected end of JSON input"},
	}

	type result struct {
		Value string `json:"value"`
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			req := NewRequest[result](http.MethodGet, "test", NoParams)
			resp := &http.Response{Body: io.NopCloser(strings.NewReader(tt.body))}

			got, err := req.unmarshallBizResponse(resp)
			if tt.wantErr != "" {
				if err == nil || !strings.Contains(err.Error(), tt.wantErr) {
					t.Fatalf("unmarshallBizResponse() error = %v, want containing %q", err, tt.wantErr)
				}
				return
			}
			if err != nil {
				t.Fatalf("unmarshallBizResponse() error = %v", err)
			}
			if got.Data.Data.Value != tt.wantValue {
				t.Fatalf("value = %q, want %q", got.Data.Data.Value, tt.wantValue)
			}
		})
	}
}

func TestRequestDoWithContext(t *testing.T) {
	client := testAPI(func(r *http.Request) (*http.Response, error) {
		if r.Method != http.MethodPost {
			t.Errorf("method = %q, want POST", r.Method)
		}
		if r.URL.Path != "/items" {
			t.Errorf("path = %q, want /items", r.URL.Path)
		}
		if got := r.Header.Get("Authorization"); got != "Bearer test-token" {
			t.Errorf("Authorization = %q", got)
		}
		if got := r.Header.Get("x-ds-pow-response"); got != "pow-answer" {
			t.Errorf("x-ds-pow-response = %q", got)
		}
		if got := r.Header.Get("Content-Type"); got != "application/json" {
			t.Errorf("Content-Type = %q", got)
		}
		body, err := io.ReadAll(r.Body)
		if err != nil {
			t.Errorf("read body: %v", err)
		}
		if got := string(body); got != `{"name":"value"}` {
			t.Errorf("body = %s", got)
		}
		return testHTTPResponse(`{}`), nil
	}).SetToken("test-token")

	req := NewRequest[struct{}](http.MethodPost, "items", map[string]string{"name": "value"})
	req.powAnswer = "pow-answer"
	resp, err := req.DoWithContext(context.Background(), client)
	if err != nil {
		t.Fatalf("DoWithContext() error = %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("status = %d, want 200", resp.StatusCode)
	}
}

func TestRequestDoWithCanceledContext(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	client := testAPI(func(r *http.Request) (*http.Response, error) {
		if err := r.Context().Err(); err != context.Canceled {
			t.Errorf("request context error = %v, want context canceled", err)
		}
		return nil, r.Context().Err()
	})
	req := NewRequest[struct{}](http.MethodGet, "test", NoParams)
	_, err := req.DoWithContext(ctx, client)
	if err == nil || !strings.Contains(err.Error(), context.Canceled.Error()) {
		t.Fatalf("DoWithContext() error = %v, want context canceled", err)
	}
}