"""
Post-process Finanzplan Excel exports: attach charts to the Dashboard sheet
and move Dashboard to be the first tab.

Run after export-finanzplan-excel.ts:
    python3 scripts/add-charts.py
"""
from __future__ import annotations

import sys
from pathlib import Path

from openpyxl import load_workbook
from openpyxl.chart import BarChart, LineChart, Reference
from openpyxl.chart.label import DataLabelList
from openpyxl.utils import get_column_letter

EXPORTS_DIR = Path(__file__).resolve().parent.parent / "exports"


def column_count_until_empty(ws, start_col: int, header_row: int) -> int:
    """Count consecutive non-empty cells starting at (header_row, start_col)."""
    c = start_col
    while ws.cell(row=header_row, column=c).value not in (None, ""):
        c += 1
    return c - start_col


def add_charts_to_workbook(path: Path) -> None:
    wb = load_workbook(path)
    if "Dashboard" not in wb.sheetnames:
        print(f"  skip {path.name}: no Dashboard tab")
        return
    ws = wb["Dashboard"]

    # --- Chart 1: YoY Revenue / Material / Personnel / EBIT ---
    # Source: rows 3..9 (3=year headers, rows 4=Umsatz, 5=Material, 6=Personal, 9=EBIT)
    # categories: B3:F3 (years), data: rows 4,5,6,9
    cat_ref = Reference(ws, min_col=2, max_col=6, min_row=3, max_row=3)
    chart1 = BarChart()
    chart1.type = "col"
    chart1.style = 11
    chart1.title = "Umsatz / Material / Personal / EBIT — YoY"
    chart1.y_axis.title = "EUR"
    chart1.x_axis.title = "Jahr"
    for r in (4, 5, 6, 9):
        data_ref = Reference(ws, min_col=1, max_col=6, min_row=r, max_row=r)
        chart1.add_data(data_ref, titles_from_data=True, from_rows=True)
    chart1.set_categories(cat_ref)
    chart1.height = 9
    chart1.width = 18
    ws.add_chart(chart1, "H3")

    # --- Chart 2: Jahresueberschuss YoY (row 11) ---
    chart2 = BarChart()
    chart2.type = "col"
    chart2.style = 13
    chart2.title = "Jahresüberschuss — YoY"
    chart2.y_axis.title = "EUR"
    chart2.x_axis.title = "Jahr"
    data_ref = Reference(ws, min_col=1, max_col=6, min_row=11, max_row=11)
    chart2.add_data(data_ref, titles_from_data=True, from_rows=True)
    chart2.set_categories(cat_ref)
    chart2.height = 9
    chart2.width = 18
    chart2.dataLabels = DataLabelList(showVal=True)
    ws.add_chart(chart2, "H22")

    # --- Chart 3: Liquidity monthly (row 16, months from col B) ---
    # Determine the last month column by scanning row 15 (month labels)
    n_months = column_count_until_empty(ws, 2, 15)
    last_col = 1 + n_months  # col 2..(1+n_months)

    chart3 = LineChart()
    chart3.title = "Liquidität (monatlich)"
    chart3.y_axis.title = "EUR"
    chart3.x_axis.title = "Monat"
    chart3.style = 12
    cat_months = Reference(ws, min_col=2, max_col=last_col, min_row=15, max_row=15)
    data_liq = Reference(ws, min_col=1, max_col=last_col, min_row=16, max_row=16)
    chart3.add_data(data_liq, titles_from_data=True, from_rows=True)
    chart3.set_categories(cat_months)
    chart3.height = 9
    chart3.width = 24
    ws.add_chart(chart3, "H41")

    # --- Chart 4: Headcount (row 20) ---
    chart4 = LineChart()
    chart4.title = "Headcount (monatlich)"
    chart4.y_axis.title = "Personen"
    chart4.x_axis.title = "Monat"
    chart4.style = 10
    data_hc = Reference(ws, min_col=1, max_col=last_col, min_row=20, max_row=20)
    chart4.add_data(data_hc, titles_from_data=True, from_rows=True)
    chart4.set_categories(cat_months)
    chart4.height = 9
    chart4.width = 24
    ws.add_chart(chart4, "H60")

    # --- Chart 5: Personalkosten total monthly (row 24) ---
    chart5 = LineChart()
    chart5.title = "Personalkosten total (monatlich)"
    chart5.y_axis.title = "EUR"
    chart5.x_axis.title = "Monat"
    chart5.style = 13
    data_pers = Reference(ws, min_col=1, max_col=last_col, min_row=24, max_row=24)
    chart5.add_data(data_pers, titles_from_data=True, from_rows=True)
    chart5.set_categories(cat_months)
    chart5.height = 9
    chart5.width = 24
    ws.add_chart(chart5, "H79")

    # --- Move Dashboard to be the first sheet ---
    idx = wb.sheetnames.index("Dashboard")
    if idx != 0:
        # openpyxl uses _sheets internal list; reorder by index.
        wb._sheets.insert(0, wb._sheets.pop(idx))
    # Also put the Formelübersicht (docs) tab at the end if present
    for docs_name in ("Formelübersicht", "Formulas"):
        if docs_name in wb.sheetnames:
            fidx = wb.sheetnames.index(docs_name)
            wb._sheets.append(wb._sheets.pop(fidx))
            break
    # Make Dashboard the active sheet on open
    wb.active = 0

    wb.save(path)
    print(f"  charts added to {path.name}")


def main() -> None:
    if not EXPORTS_DIR.exists():
        print(f"no exports dir at {EXPORTS_DIR}")
        sys.exit(1)
    files = sorted(EXPORTS_DIR.glob("Finanzplan-*.xlsx"))
    if not files:
        print("no Finanzplan-*.xlsx files found in exports/")
        sys.exit(1)
    for f in files:
        print(f"Processing {f.name}")
        add_charts_to_workbook(f)


if __name__ == "__main__":
    main()