"""
experiment.py

Замеры производительности трёх структур данных на одних и тех же данных:
    LinkedList, HashTable, BST
в двух режимах:
    случайный порядок (shuffled), отсортированный порядок (sorted)
для трёх операций:
    insert N записей, find 110 раз, delete 50 раз
Каждый эксперимент повторяется TRIALS раз. Сохраняем все замеры + средние
в CSV. Для BST на отсортированных данных снижаем N - иначе эксперимент
длится десятки минут (вырожденное дерево, O(N^2) вставка).
"""

import csv
import os
import random
import time

import phonebook as pb


# ---------- параметры эксперимента ----------
N = 10_000               # число записей в основном эксперименте
N_BST_SORTED = 2_000     # для BST на отсортированных данных - меньше (O(N^2))
TRIALS = 5               # количество повторов каждого замера
N_FIND_EXISTING = 100
N_FIND_MISSING = 10
N_DELETE = 50
HT_SIZE = 2048           # размер хеш-таблицы
RNG_SEED = 42
OUT_CSV = os.path.join("docs", "data", "results.csv")
# --------------------------------------------


def gen_records(n):
    """Генерирует n записей вида ('User_00001', '555-0001-...')."""
    return [(f"User_{i:05d}", f"555-{i:07d}") for i in range(n)]


def pick_keys(records, k_exist, k_miss, rng):
    """Выбирает k_exist существующих имён и k_miss отсутствующих."""
    existing = [name for name, _ in rng.sample(records, k_exist)]
    missing = [f"None_{i}" for i in range(k_miss)]
    return existing + missing


# ---------- замеры по структурам ----------

def measure_linked_list(records, find_keys, delete_keys):
    # вставка
    t0 = time.perf_counter()
    head = pb.ll_create()
    for name, phone in records:
        head = pb.ll_insert(head, name, phone)
    t_insert = time.perf_counter() - t0

    # поиск
    t0 = time.perf_counter()
    for name in find_keys:
        pb.ll_find(head, name)
    t_find = time.perf_counter() - t0

    # удаление
    t0 = time.perf_counter()
    for name in delete_keys:
        head = pb.ll_delete(head, name)
    t_delete = time.perf_counter() - t0

    return t_insert, t_find, t_delete


def measure_hash_table(records, find_keys, delete_keys):
    t0 = time.perf_counter()
    ht = pb.ht_create(size=HT_SIZE)
    for name, phone in records:
        pb.ht_insert(ht, name, phone)
    t_insert = time.perf_counter() - t0

    t0 = time.perf_counter()
    for name in find_keys:
        pb.ht_find(ht, name)
    t_find = time.perf_counter() - t0

    t0 = time.perf_counter()
    for name in delete_keys:
        pb.ht_delete(ht, name)
    t_delete = time.perf_counter() - t0

    return t_insert, t_find, t_delete


def measure_bst(records, find_keys, delete_keys):
    t0 = time.perf_counter()
    root = pb.bst_create()
    for name, phone in records:
        root = pb.bst_insert(root, name, phone)
    t_insert = time.perf_counter() - t0

    t0 = time.perf_counter()
    for name in find_keys:
        pb.bst_find(root, name)
    t_find = time.perf_counter() - t0

    t0 = time.perf_counter()
    for name in delete_keys:
        root = pb.bst_delete(root, name)
    t_delete = time.perf_counter() - t0

    return t_insert, t_find, t_delete


# ---------- запуск ----------

def run_one(structure_name, mode, n, rng_seed):
    """Готовит данные, прогоняет TRIALS раз и возвращает список (insert, find, delete)."""
    base_records = gen_records(n)

    runs = []
    for trial in range(TRIALS):
        # отдельный rng для воспроизводимости и независимости попыток
        rng = random.Random(rng_seed + trial)

        if mode == "shuffled":
            records = base_records[:]
            rng.shuffle(records)
        elif mode == "sorted":
            records = sorted(base_records, key=lambda x: x[0])
        else:
            raise ValueError(mode)

        find_keys = pick_keys(records, N_FIND_EXISTING, N_FIND_MISSING, rng)
        delete_keys = [name for name, _ in rng.sample(records, N_DELETE)]

        if structure_name == "LinkedList":
            r = measure_linked_list(records, find_keys, delete_keys)
        elif structure_name == "HashTable":
            r = measure_hash_table(records, find_keys, delete_keys)
        elif structure_name == "BST":
            r = measure_bst(records, find_keys, delete_keys)
        else:
            raise ValueError(structure_name)

        runs.append(r)
    return runs


def main():
    os.makedirs(os.path.dirname(OUT_CSV), exist_ok=True)

    rows = [["Структура", "Режим", "Операция", "N", "Trial", "Время (сек)"]]
    summary = []   # (structure, mode, op, n, mean, all_trials)

    configs = [
        ("LinkedList", "shuffled", N),
        ("LinkedList", "sorted",   N),
        ("HashTable",  "shuffled", N),
        ("HashTable",  "sorted",   N),
        ("BST",        "shuffled", N),
        ("BST",        "sorted",   N_BST_SORTED),   # вырожденный случай
    ]

    for structure, mode, n in configs:
        print(f"==> {structure:10s} | {mode:9s} | N={n}")
        runs = run_one(structure, mode, n, RNG_SEED)
        # runs = [(insert, find, delete), ...]
        ops = ["insert", "find", "delete"]
        for op_idx, op in enumerate(ops):
            vals = [r[op_idx] for r in runs]
            mean = sum(vals) / len(vals)
            for trial_idx, v in enumerate(vals):
                rows.append([structure, mode, op, n, trial_idx + 1, f"{v:.6f}"])
            summary.append((structure, mode, op, n, mean, vals))
            print(f"    {op:7s}: mean={mean*1000:.3f} ms  "
                  f"runs={[f'{v*1000:.3f}' for v in vals]}")

    # сводная строка со средними
    rows.append([])
    rows.append(["--- СРЕДНИЕ ---"])
    rows.append(["Структура", "Режим", "Операция", "N",
                 "Среднее (сек)", "Все замеры (сек)"])
    for s, mode, op, n, mean, vals in summary:
        rows.append([s, mode, op, n, f"{mean:.6f}",
                     ";".join(f"{v:.6f}" for v in vals)])

    with open(OUT_CSV, "w", newline="", encoding="utf-8") as f:
        writer = csv.writer(f)
        writer.writerows(rows)

    print(f"\nГотово. Результаты записаны в {OUT_CSV}")


if __name__ == "__main__":
    main()