from __future__ import annotations

import json
from pathlib import Path

import click

from src.taetigkeitsnachweis.errors import TaetigkeitsnachweisError
from src.taetigkeitsnachweis.logging_utils import configure_logging
from src.taetigkeitsnachweis.matcher import match_assignments
from src.taetigkeitsnachweis.parser import parse_allocation_records, parse_masterdata_records
from src.taetigkeitsnachweis.validator import validate_business_rules, validate_sources
from src.taetigkeitsnachweis.writer import (
    build_employee_workbooks,
    build_output_filename,
    save_employee_workbooks,
)


def _load_config(project_root: Path) -> dict:
    config_path = project_root / "config.json"
    with config_path.open("r", encoding="utf-8") as config_file:
        return json.load(config_file)


def _print_issues(issues: list, title: str) -> None:
    if not issues:
        return
    click.echo(title)
    for issue in issues:
        click.echo(f"- [{issue.severity}] {issue.code}: {issue.message}")


def _print_preview(month: int, year: int, matched_assignments: list, planned_files: list[str]) -> None:
    click.echo("=== Vorschau der ermittelten Werte ===")
    click.echo(f"Berichtsmonat : {month:02d}/{year}")
    click.echo(f"Aktive Faelle : {len(matched_assignments)}")
    click.echo("--- Zu erzeugende Taetigkeitsnachweise ---")
    for item in matched_assignments:
        click.echo(
            "- "
            f"{item.allocation.employee_name} | "
            f"{item.masterdata.funktion} | "
            f"{item.foerderquote_percent:.2f}%"
        )

    click.echo("--- Geplante Ausgabedateien ---")
    for file_name in planned_files:
        click.echo(f"- {file_name}")


@click.command()
@click.option("--month", type=click.IntRange(1, 12), required=True)
@click.option("--year", type=click.IntRange(2000, 2100), required=True)
@click.option("--yes", is_flag=True, default=False, help="Skip interactive confirmation.")
def main(month: int, year: int, yes: bool) -> None:
    configure_logging()
    project_root = Path(__file__).resolve().parent

    try:
        config = _load_config(project_root)

        source_issues = validate_sources(
            config=config,
            report_month=month,
            report_year=year,
            project_root=project_root,
        )
        _print_issues(source_issues, "=== Source validation ===")
        if any(issue.severity == "error" for issue in source_issues):
            raise click.ClickException("Source validation failed.")

        allocation_records = parse_allocation_records(
            config=config,
            report_month=month,
            report_year=year,
            project_root=project_root,
        )
        masterdata_records = parse_masterdata_records(
            config=config,
            project_root=project_root,
        )

        matched_assignments, match_issues = match_assignments(
            allocation_records=allocation_records,
            masterdata_records=masterdata_records,
            config=config,
        )
        _print_issues(match_issues, "=== Matching issues ===")

        business_issues = validate_business_rules(
            config=config,
            report_month=month,
            report_year=year,
            allocation_records=allocation_records,
            matched_assignments=matched_assignments,
            project_root=project_root,
        )
        _print_issues(business_issues, "=== Business validation ===")

        all_issues = [*match_issues, *business_issues]
        if any(issue.severity == "error" for issue in all_issues):
            raise click.ClickException("Validation failed after matching.")

        filename_pattern = config["output"]["filename_pattern"]
        unique_employees = sorted({item.allocation.employee_name for item in matched_assignments})
        planned_files = [
            build_output_filename(
                filename_pattern=filename_pattern,
                employee_name=employee_name,
                report_year=year,
                report_month=month,
            )
            for employee_name in unique_employees
        ]

        _print_preview(
            month=month,
            year=year,
            matched_assignments=matched_assignments,
            planned_files=planned_files,
        )

        if not yes:
            confirmed = click.confirm("Dateien jetzt schreiben?", default=False)
            if not confirmed:
                click.echo("Abbruch ohne Schreibzugriff.")
                return

        employee_workbooks = build_employee_workbooks(
            config=config,
            matched_assignments=matched_assignments,
            report_month=month,
            report_year=year,
            project_root=project_root,
        )
        output_paths = save_employee_workbooks(
            config=config,
            employee_workbooks=employee_workbooks,
            report_month=month,
            report_year=year,
            project_root=project_root,
        )

        click.echo("=== Generated files ===")
        for output_path in output_paths:
            click.echo(f"- {output_path}")

    except TaetigkeitsnachweisError as exc:
        raise click.ClickException(str(exc)) from exc


if __name__ == "__main__":
    main()