package main

import (
	"bytes"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"testing"

	"github.com/gin-gonic/gin"
)

type testDB struct {
	file string
	data string
}

func (tdb *testDB) setup() {
	err := os.WriteFile(tdb.file, []byte(tdb.data), 0644)
	if err != nil {
		panic(err)
	}
}

func (tdb *testDB) teardown() {
	_ = os.Remove(tdb.file)
}

func TestChatEndpoint_MatchFound(t *testing.T) {
	tdb := testDB{
		file: "db.yaml",
		data: `
- id: deworming
  reason: Deworming for dogs
  keywords: ["worms", "deworming", "parasite"]
  procedures:
    - name: Deworming tablet
      price: 30
      duration_minutes: 10
    - name: Bloodwork
      price: 35
      duration_minutes: 35
  notes: Bloodwork ensures organs are safe for treatment.
- id: vaccination
  reason: Annual vaccination
  keywords: ["vaccine", "vaccination", "shots"]
  procedures:
    - name: Vaccine injection
      price: 50
      duration_minutes: 15
`,
	}
	tdb.setup()
	defer tdb.teardown()

	if err := loadYAMLDB(tdb.file); err != nil {
		t.Fatalf("Failed to load test db: %v", err)
	}

	r := setupRouter()

	w := httptest.NewRecorder()
	body := map[string]string{"message": "My dog needs deworming and bloodwork"}
	jsonBody, _ := json.Marshal(body)
	req, _ := http.NewRequest("POST", "/chat", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("Expected 200, got %d", w.Code)
	}
	respBody, _ := io.ReadAll(w.Body)
	if !bytes.Contains(respBody, []byte("deworming")) {
		t.Errorf("Expected match for deworming, got %s", string(respBody))
	}
}

func TestChatEndpoint_NoMatch(t *testing.T) {
	tdb := testDB{
		file: "db.yaml",
		data: `
- id: vaccination
  reason: Annual vaccination
  keywords: ["vaccine", "vaccination", "shots"]
  procedures:
    - name: Vaccine injection
      price: 50
      duration_minutes: 15
`,
	}
	tdb.setup()
	defer tdb.teardown()

	if err := loadYAMLDB(tdb.file); err != nil {
		t.Fatalf("Failed to load test db: %v", err)
	}

	r := setupRouter()

	w := httptest.NewRecorder()
	body := map[string]string{"message": "My dog has worms"}
	jsonBody, _ := json.Marshal(body)
	req, _ := http.NewRequest("POST", "/chat", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("Expected 200, got %d", w.Code)
	}
	respBody, _ := io.ReadAll(w.Body)
	if !bytes.Contains(respBody, []byte(`"match":null`)) {
		t.Errorf("Expected no match, got %s", string(respBody))
	}
}

func setupRouter() *gin.Engine {
	r := gin.Default()
	r.POST("/chat", func(c *gin.Context) {
		var req ChatRequest
		if err := c.ShouldBindJSON(&req); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid request"})
			return
		}
		keywords := naiveKeywordExtract(req.Message)
		candidates := findCandidates(keywords)
		if len(candidates) == 0 {
			c.JSON(http.StatusOK, ChatResponse{Match: nil})
			return
		}
		best := candidates[0]
		totalPrice, totalDuration := sumProcedures(best.Procedures)
		c.JSON(http.StatusOK, ChatResponse{
			Match:         &best.ID,
			Procedures:    best.Procedures,
			TotalPrice:    totalPrice,
			TotalDuration: totalDuration,
			Notes:         best.Notes,
		})
	})
	return r
}