package main

import (
	"context"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestBrainClient_Query_Success(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, http.MethodPost, r.Method)
		assert.Equal(t, "/query", r.URL.Path)

		body, _ := io.ReadAll(r.Body)
		var got struct {
			Query string `json:"query"`
			Limit int    `json:"limit"`
		}
		require.NoError(t, json.Unmarshal(body, &got))
		assert.Equal(t, "find-h", got.Query)
		assert.Equal(t, 3, got.Limit)

		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"results":[{"path":"knowledge/x.md","title":"x","excerpt":"...","score":7}]}`))
	}))
	defer srv.Close()

	c := &brainClient{baseURL: srv.URL, http: srv.Client()}
	res, err := c.Query(context.Background(), "find-h", 3)
	require.NoError(t, err)
	require.Len(t, res.Results, 1)
	assert.Equal(t, "knowledge/x.md", res.Results[0].Path)
	assert.Equal(t, 7, res.Results[0].Score)
}

func TestBrainClient_Query_TransportError(t *testing.T) {
	c := &brainClient{baseURL: "http://127.0.0.1:1", http: http.DefaultClient}
	_, err := c.Query(context.Background(), "x", 5)
	assert.Error(t, err)
}

func TestBrainClient_Query_Non200(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
		_, _ = w.Write([]byte("boom"))
	}))
	defer srv.Close()

	c := &brainClient{baseURL: srv.URL, http: srv.Client()}
	_, err := c.Query(context.Background(), "x", 5)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "500")
}

func TestBrainClient_Write_Success(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, "/write", r.URL.Path)
		assert.Equal(t, http.MethodPost, r.Method)
		body, _ := io.ReadAll(r.Body)
		var got struct {
			Type    string `json:"type"`
			Slug    string `json:"slug"`
			Content string `json:"content"`
		}
		require.NoError(t, json.Unmarshal(body, &got))
		assert.Equal(t, "knowledge", got.Type)
		assert.Equal(t, "find-h", got.Slug)
		assert.Equal(t, "# body\n", got.Content)
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"path":"knowledge/find-h.md"}`))
	}))
	defer srv.Close()

	c := &brainClient{baseURL: srv.URL, http: srv.Client()}
	res, err := c.Write(context.Background(), "knowledge", "find-h", strings.NewReader("# body\n"))
	require.NoError(t, err)
	assert.Equal(t, "knowledge/find-h.md", res.Path)
}

func TestNewBrainClient_DefaultURL(t *testing.T) {
	t.Setenv("BRAIN_URL", "")
	c := newBrainClient()
	assert.Equal(t, "http://koala:30330", c.baseURL)
}

func TestNewBrainClient_OverrideURL(t *testing.T) {
	t.Setenv("BRAIN_URL", "http://localhost:9999")
	c := newBrainClient()
	assert.Equal(t, "http://localhost:9999", c.baseURL)
}