import json
import pandas as pd
import os
from pypdf import PdfReader
import re
from tqdm import tqdm
from openai import AzureOpenAI, Client
from prompts import ESTIMATE_COST_OF_CAR_PARTS_REPLACEMENT_PROMPT
import ast
import time


def extract_invoice_tables(invoices_path: str) -> list[str]:
    invoices_paths = [os.path.join(invoices_path, invoice) for invoice in os.listdir(invoices_path) if
                      invoice.endswith(".pdf")]
    invoices_tables = []
    for invoice_path in tqdm(invoices_paths):
        reader = PdfReader(invoice_path)
        page = reader.pages[0]
        text = page.extract_text()

        table_text = re.search(r"Beschädigtes Teil.*?Gesamtsumme:.*?EUR", text, re.DOTALL).group()

        lines = table_text.splitlines()
        header = lines[0]
        other_text = "\n".join(lines[1:])
        cleaned_text = re.sub(r"(?<!\d)\n", " ", other_text)

        table = header + "\n" + cleaned_text

        inv = table.split("\n")
        reformatted_inv = "Beschädigtes Teil | Teilkosten (EUR) | Arbeitsstunden | Arbeitskosten (EUR/Stunde) | Gesamtkosten (EUR)\n" + "\n".join(
            " ".join(inv[i].split(" ")[:-4]) + " | " + ' | '.join(inv[i].split(" ")[-4:]) for i in
            range(1, len(inv) - 1)) + "\n" + inv[-1]

        invoices_tables.append(reformatted_inv)

    return invoices_tables


def generate_response(client: Client, car_parts: list[str]):

    response = client.chat.completions.create(
        model="gpt-4o",
        messages=[
            {
                "role": "user",
                "content": [
                    {"type": "text", "text": ESTIMATE_COST_OF_CAR_PARTS_REPLACEMENT_PROMPT("\n".join(car_parts))},
                ],
            }
        ],
        max_tokens=1024,
        temperature=0.5,
    )

    message = response.choices[0].message.content
    message = message.replace("```python", "").replace("```", "")
    return message


def get_car_parts(invoices: list[str]) -> list[tuple[str, str, str]]:
    car_parts = []
    for invoice in invoices:
        car_parts += [
            (
                line.split(" | ")[0].replace("(rechts)", "").replace("(links)", "").replace("links", "").replace("rechts", "").strip(),
                line.split(" | ")[1],
                line.split(" | ")[2]
            )
            for line in invoice.split("\n")[1:-1]
        ]
    return car_parts


def prompt_model_for_cost_estimation(
        parts_to_estimate: list[str],
        batch_size: int = 100
) -> list[tuple[str, float, float]]:
    car_parts = []
    client = AzureOpenAI(
        api_key=os.environ["AZURE_API_KEY"],
        api_version=os.environ["AZURE_API_VERSION"],
        azure_endpoint=os.environ["AZURE_ENDPOINT"],
    )
    for i in tqdm(range(0, len(parts_to_estimate), batch_size)):
        try:
            batch = parts_to_estimate[i:i + batch_size]
            response = generate_response(client, batch)
            car_parts.extend(ast.literal_eval(response))
            time.sleep(5)
        except Exception as e:
            print(f"Error: {e}")
    return car_parts


def estimate_costs(invoices_folder_path: str, path_to_save_json: str) -> pd.DataFrame:
    invoices = extract_invoice_tables(invoices_folder_path)
    car_parts = get_car_parts(invoices)

    car_parts_df = pd.DataFrame(car_parts, columns=["car_part", "cost", "hours"])
    parts_to_estimate = car_parts_df["car_part"].unique().tolist()
    for i in range(3):
        car_parts += prompt_model_for_cost_estimation(parts_to_estimate)

    car_parts_df = pd.DataFrame(car_parts, columns=["car_part", "cost", "hours"])

    car_parts_df["cost"] = car_parts_df["cost"].astype(float)
    car_parts_df["hours"] = car_parts_df["hours"].astype(float)
    car_parts_df_grouped = car_parts_df.groupby("car_part").agg(
        {"cost": ["mean", "min", "max", "count"], "hours": ["mean", "min", "max"]}
    )
    car_parts_df_grouped.columns = [
        "average_cost", "cost_min", "cost_max", "count", "average_hours", "hours_min", "hours_max"
    ]

    car_parts_dict = car_parts_df_grouped.to_dict(
        orient="index"
    )

    with open(path_to_save_json, "w", encoding="utf-8") as f:
        json.dump(car_parts_dict, f, ensure_ascii=False, indent=4)

    return car_parts_df_grouped