package main

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	_ "modernc.org/sqlite"
)

func setupTestServer(t *testing.T) (*httptest.Server, *sql.DB) {
	t.Helper()
	db, err := sql.Open("sqlite", ":memory:")
	if err != nil {
		t.Fatal(err)
	}
	InitDB(db)
	return httptest.NewServer(NewRouter(db)), db
}

func TestCreateTodo(t *testing.T) {
	ts, db := setupTestServer(t)
	defer ts.Close()
	defer db.Close()

	resp, err := http.Post(ts.URL+"/todos", "application/json",
		strings.NewReader(`{"title":"Buy groceries","priority":2}`))
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusCreated {
		t.Fatalf("expected 201, got %d", resp.StatusCode)
	}
	var body map[string]interface{}
	json.NewDecoder(resp.Body).Decode(&body)
	if body["title"] != "Buy groceries" {
		t.Fatalf("expected title 'Buy groceries', got %v", body["title"])
	}
	if body["id"] == nil {
		t.Fatal("expected id to be present")
	}
}

func TestListTodos(t *testing.T) {
	ts, db := setupTestServer(t)
	defer ts.Close()
	defer db.Close()

	http.Post(ts.URL+"/todos", "application/json",
		strings.NewReader(`{"title":"Listable task"}`))

	resp, err := http.Get(ts.URL + "/todos")
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("expected 200, got %d", resp.StatusCode)
	}
	var body []map[string]interface{}
	json.NewDecoder(resp.Body).Decode(&body)
	if len(body) < 1 {
		t.Fatal("expected at least 1 todo")
	}
}

func TestGetTodoByID(t *testing.T) {
	ts, db := setupTestServer(t)
	defer ts.Close()
	defer db.Close()

	resp, _ := http.Post(ts.URL+"/todos", "application/json",
		strings.NewReader(`{"title":"Fetchable task"}`))
	var created map[string]interface{}
	json.NewDecoder(resp.Body).Decode(&created)
	resp.Body.Close()

	id := created["id"].(float64)
	resp, err := http.Get(ts.URL + "/todos/" + fmt.Sprintf("%.0f", id))
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("expected 200, got %d", resp.StatusCode)
	}
	var body map[string]interface{}
	json.NewDecoder(resp.Body).Decode(&body)
	if body["id"] != id {
		t.Fatalf("expected id %.0f, got %v", id, body["id"])
	}
}

func TestGetTodoNotFound(t *testing.T) {
	ts, db := setupTestServer(t)
	defer ts.Close()
	defer db.Close()

	resp, err := http.Get(ts.URL + "/todos/99999")
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNotFound {
		t.Fatalf("expected 404, got %d", resp.StatusCode)
	}
}

func TestUpdateTodo(t *testing.T) {
	ts, db := setupTestServer(t)
	defer ts.Close()
	defer db.Close()

	resp, _ := http.Post(ts.URL+"/todos", "application/json",
		strings.NewReader(`{"title":"Old title"}`))
	var created map[string]interface{}
	json.NewDecoder(resp.Body).Decode(&created)
	resp.Body.Close()

	id := created["id"].(float64)
	req, _ := http.NewRequest(http.MethodPut, ts.URL+"/todos/"+fmt.Sprintf("%.0f", id),
		strings.NewReader(`{"title":"New title"}`))
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("expected 200, got %d", resp.StatusCode)
	}
	var body map[string]interface{}
	json.NewDecoder(resp.Body).Decode(&body)
	if body["title"] != "New title" {
		t.Fatalf("expected 'New title', got %v", body["title"])
	}
}

func TestDeleteTodo(t *testing.T) {
	ts, db := setupTestServer(t)
	defer ts.Close()
	defer db.Close()

	resp, _ := http.Post(ts.URL+"/todos", "application/json",
		strings.NewReader(`{"title":"Deletable task"}`))
	var created map[string]interface{}
	json.NewDecoder(resp.Body).Decode(&created)
	resp.Body.Close()

	id := created["id"].(float64)
	req, _ := http.NewRequest(http.MethodDelete, ts.URL+"/todos/"+fmt.Sprintf("%.0f", id), nil)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent {
		t.Fatalf("expected 204, got %d", resp.StatusCode)
	}

	resp, _ = http.Get(ts.URL + "/todos/" + fmt.Sprintf("%.0f", id))
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNotFound {
		t.Fatalf("expected 404 after delete, got %d", resp.StatusCode)
	}
}