diff --git a/src/controllers/.gitkeep b/src/controllers/.gitkeep
deleted file mode 100644
index e69de29..0000000
diff --git a/src/controllers/pokemonController.test.ts b/src/controllers/pokemonController.test.ts
new file mode 100644
index 0000000..1baacd7
--- /dev/null
+++ b/src/controllers/pokemonController.test.ts
@@ -0,0 +1,129 @@
+// generated with AI 
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import {
+  matchesFilter,
+  GetNext,
+  GetPrev,
+  GetNextFiltered,
+  GetPrevFiltered,
+  type PokemonData,
+  type FilterRules,
+} from "./pokemonController";
+import * as pokemonApi from "../api/pokemon";
+
+vi.mock("../api/pokemon", () => ({
+  getPokemonByID: vi.fn(),
+}));
+
+describe("pokemonController", () => {
+  const mockPikachu: PokemonData = {
+    id: 25,
+    name: "pikachu",
+    sprites: { front_default: "pikachu.png" },
+    stats: [
+      { base_stat: 35, stat: { name: "hp" } },
+      { base_stat: 55, stat: { name: "attack" } },
+      { base_stat: 40, stat: { name: "defense" } },
+      { base_stat: 50, stat: { name: "special-attack" } },
+      { base_stat: 50, stat: { name: "special-defense" } },
+      { base_stat: 90, stat: { name: "speed" } },
+    ],
+    height: 4, // 0.4 m
+    weight: 60, // 6.0 kg
+    types: [{ type: { name: "electric" } }],
+    abilities: [
+      { ability: { name: "static" }, is_hidden: false },
+      { ability: { name: "lightning-rod" }, is_hidden: true },
+    ],
+  };
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe("matchesFilter", () => {
+    it("dovrebbe restituire true quando nessun filtro è applicato", () => {
+      expect(matchesFilter(mockPikachu, {})).toBe(true);
+    });
+
+    it("dovrebbe filtrare correttamente per tipo", () => {
+      expect(matchesFilter(mockPikachu, { type: ["electric"] })).toBe(true);
+      expect(matchesFilter(mockPikachu, { type: ["fire"] })).toBe(false);
+    });
+
+    it("dovrebbe filtrare correttamente per abilità", () => {
+      expect(matchesFilter(mockPikachu, { ability: "static" })).toBe(true);
+      expect(matchesFilter(mockPikachu, { ability: "blaze" })).toBe(false);
+    });
+
+    it("dovrebbe verificare i range numerici di altezza e peso", () => {
+      const validRules: FilterRules = { height: "0-1", weight: "5-10" };
+      const invalidRules: FilterRules = { height: "1-2", weight: "5-10" };
+
+      expect(matchesFilter(mockPikachu, validRules)).toBe(true);
+      expect(matchesFilter(mockPikachu, invalidRules)).toBe(false);
+    });
+
+    it("dovrebbe calcolare e filtrare correttamente le statistiche totali", () => {
+      expect(matchesFilter(mockPikachu, { total: "300-350" })).toBe(true);
+      expect(matchesFilter(mockPikachu, { total: "400-500" })).toBe(false);
+    });
+  });
+
+  describe("GetNext / GetPrev", () => {
+    it("dovrebbe recuperare il Pokémon successivo", async () => {
+      vi.spyOn(pokemonApi, "getPokemonByID").mockResolvedValueOnce(mockPikachu);
+
+      const result = await GetNext(24);
+      expect(pokemonApi.getPokemonByID).toHaveBeenCalledWith(25);
+      expect(result).toEqual(mockPikachu);
+    });
+
+    it("dovrebbe restituire null se si supera il limite MAX_POKEMON_ID", async () => {
+      const result = await GetNext(1025);
+      expect(result).toBeNull();
+      expect(pokemonApi.getPokemonByID).not.toHaveBeenCalled();
+    });
+
+    it("dovrebbe restituire null se currentId <= 1 per GetPrev", async () => {
+      const result = await GetPrev(1);
+      expect(result).toBeNull();
+      expect(pokemonApi.getPokemonByID).not.toHaveBeenCalled();
+    });
+
+    it("dovrebbe gestire gli errori API restituendo null", async () => {
+      vi.spyOn(pokemonApi, "getPokemonByID").mockRejectedValueOnce(new Error("API Error"));
+
+      const result = await GetNext(10);
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("GetNextFiltered / GetPrevFiltered", () => {
+    it("dovrebbe trovare il prossimo Pokémon che rispetta i filtri", async () => {
+      const Charmander: PokemonData = { ...mockPikachu, id: 4, types: [{ type: { name: "fire" } }] };
+
+      vi.spyOn(pokemonApi, "getPokemonByID")
+        .mockResolvedValueOnce(mockPikachu)
+        .mockResolvedValueOnce(Charmander);
+
+      const result = await GetNextFiltered(2, { type: ["fire"] });
+
+      expect(pokemonApi.getPokemonByID).toHaveBeenCalledTimes(2);
+      expect(result).toEqual(Charmander);
+    });
+
+    it("dovrebbe trovare il Pokémon precedente che rispetta i filtri", async () => {
+      const Bulbasaur: PokemonData = { ...mockPikachu, id: 1, types: [{ type: { name: "grass" } }] };
+
+      vi.spyOn(pokemonApi, "getPokemonByID")
+        .mockResolvedValueOnce(mockPikachu)
+        .mockResolvedValueOnce(Bulbasaur);
+
+      const result = await GetPrevFiltered(3, { type: ["grass"] });
+
+      expect(pokemonApi.getPokemonByID).toHaveBeenCalledTimes(2);
+      expect(result).toEqual(Bulbasaur);
+    });
+  });
+});
\ No newline at end of file
diff --git a/src/controllers/pokemonController.ts b/src/controllers/pokemonController.ts
new file mode 100644
index 0000000..18926a7
--- /dev/null
+++ b/src/controllers/pokemonController.ts
@@ -0,0 +1,122 @@
+import { getPokemonByID } from "../api/pokemon";
+
+export type PokemonData = {
+  id: number;
+  name: string;
+  sprites: { front_default: string };
+  stats: Array<{ base_stat: number; stat: { name: string } }>;
+  height: number;
+  weight: number;
+  types: Array<{ type: { name: string } }>;
+  abilities: Array<{ ability: { name: string }; is_hidden: boolean }>;
+};
+
+export interface FilterRules {
+  type?: string[];
+  ability?: string;
+  height?: string;
+  weight?: string;
+  hp?: string;
+  attack?: string;
+  defense?: string;
+  specialAttack?: string;
+  specialDefense?: string;
+  speed?: string;
+  total?: string;
+}
+
+const MAX_POKEMON_ID = 1025;
+
+function isInRange(val: number, rangeStr?: string): boolean {
+  if (!rangeStr) return true;
+  const [min, max] = rangeStr.split("-").map(Number);
+  return val >= min && val <= max;
+}
+
+// Validation logic based on provided rules
+export function matchesFilter(pokemon: PokemonData, rules: FilterRules): boolean {
+  if (rules.type && rules.type.length > 0) {
+    const hasType = pokemon.types.some((t) => rules.type?.includes(t.type.name));
+    if (!hasType) return false;
+  }
+
+  if (rules.ability && rules.ability.trim() !== "") {
+    const hasAbility = pokemon.abilities.some((a) =>
+      a.ability.name.toLowerCase().includes(rules.ability!.toLowerCase())
+    );
+    if (!hasAbility) return false;
+  }
+
+  if (!isInRange(pokemon.height / 10, rules.height)) return false;
+  if (!isInRange(pokemon.weight / 10, rules.weight)) return false;
+
+  const getStat = (name: string) =>
+    pokemon.stats.find((s) => s.stat.name === name)?.base_stat || 0;
+
+  if (!isInRange(getStat("hp"), rules.hp)) return false;
+  if (!isInRange(getStat("attack"), rules.attack)) return false;
+  if (!isInRange(getStat("defense"), rules.defense)) return false;
+  if (!isInRange(getStat("special-attack"), rules.specialAttack)) return false;
+  if (!isInRange(getStat("special-defense"), rules.specialDefense)) return false;
+  if (!isInRange(getStat("speed"), rules.speed)) return false;
+
+  const totalStats = pokemon.stats.reduce((acc, s) => acc + s.base_stat, 0);
+  if (!isInRange(totalStats , rules.total)) return false;
+
+  return true;
+}
+
+// fetches a pokemon by id and returns null in case of an error
+async function fetchSafe(id: number): Promise<PokemonData | null> {
+  try {
+    return await getPokemonByID(id);
+  } catch {
+    return null;
+  }
+}
+
+
+
+export async function GetNext(currentId: number): Promise<PokemonData | null> {
+  if (currentId >= MAX_POKEMON_ID) return null;
+  return await fetchSafe(currentId + 1);
+}
+
+export async function GetPrev(currentId: number): Promise<PokemonData | null> {
+  if (currentId <= 1) return null;
+  return await fetchSafe(currentId - 1);
+}
+
+
+export async function GetPrevFiltered(
+  currentId: number,
+  filters: FilterRules
+): Promise<PokemonData | null> {
+  let prevId = currentId - 1;
+
+  while (prevId >= 1) {
+    const pokemon = await fetchSafe(prevId);
+    if (pokemon && matchesFilter(pokemon, filters)) {
+      return pokemon;
+    }
+    prevId--;
+  }
+  return null;
+}
+
+export async function GetNextFiltered(
+  currentId: number,
+  filters: FilterRules
+): Promise<PokemonData | null> {
+  let nextId = currentId + 1;
+
+  while (nextId <= MAX_POKEMON_ID) {
+    const pokemon = await fetchSafe(nextId);
+    if (pokemon && matchesFilter(pokemon, filters)) {
+      return pokemon;
+    }
+    nextId++;
+  }
+  return null;
+}
+