# /// script
# requires-python = ">=3.12"
# dependencies = ["typer", "rich", "xlwings"]
# ///
from contextlib import contextmanager
from pathlib import Path
from typing import Annotated

import xlwings as xw
import typer
from rich.console import Console

console = Console()


def get_totals(book: xw.Book):
    for sheet in book.sheets:
        if sheet.name.endswith("Rate"):
            continue
        try:
            total = float(sheet.range("S3").expand("down").value[-1])
        except Exception as e:
            console.print(f"[red]Error reading total from sheet {sheet.name}: {e}[/red]")
            console.print_exception(show_locals=False)
        else:
            yield sheet.name, total


def get_grand_total(book: xw.Book):
    totals = dict(get_totals(book))
    grand_total = sum(totals.values())
    return grand_total


@contextmanager
def switch_values(book: xw.Book):
    og_vals = book.sheets['GSA Rate'].range("B2").expand("down").value
    try:
        book.sheets['GSA Rate'].range("B2").expand("down").value = 0.70
        yield
    finally:
        book.sheets['GSA Rate'].range("B2").expand("down").options(transpose=True).value = og_vals


def get_diff(book: xw.Book):
    book.sheets['GSA Rate'].range("B2:B10").value = 0.67
    initial = get_grand_total(book)

    with switch_values(book):
        fixed = get_grand_total(book)

    diff = round(fixed - initial, 2)
    return diff


def get_all_diffs(base: Path):
    reports = [f for f in base.glob('*Mileage*.xlsx') if f.is_file() and not f.stem.startswith('~$')]
    console.print(f"Found {len(reports)} report(s).")
    for r in reports:
        with console.status(f'Processing [bold blue]{r.name}[/bold blue]'):
            console.print('Opening workbook...')
            book = xw.Book(r)
            try:
                console.print('Calculating totals...')
                diff = get_diff(book)
                yield r.name, diff
                console.print(f"[cyan]Report:[/] {r.name}")
                console.print(f"  Difference after rate change: [bold green]${diff:.2f}[/]")
            except Exception as e:
                console.print(f"[red]Error processing {r.name}: {e}[/red]")
            finally:
                book.close()


def main(
    directory: Annotated[
        Path,
        typer.Argument(
            exists=True,
            file_okay=False,
            dir_okay=True,
            readable=True,
            writable=True,
            resolve_path=True
        )
    ] = None) -> None:
    console.print(f"Processing files in directory: {directory}")
    results = dict(get_all_diffs(directory))
    with Path('results.csv').open('w', encoding='utf-8') as f:
        f.write("Report,Difference\n")
        for report, diff in results.items():
            f.write(f'{report},{diff}\n')


if __name__ == "__main__":
    typer.run(main)