from __future__ import annotations

from typing import Any

VALID_TYPES = {"first_submission", "revised_submission", "final_submission", "model_only_review"}


def normalize_submission_type(value: str) -> str:
    key = str(value or "first_submission").strip().lower().replace(" ", "_")
    aliases = {
        "first": "first_submission",
        "revision": "revised_submission",
        "revised": "revised_submission",
        "final": "final_submission",
        "model": "model_only_review",
    }
    key = aliases.get(key, key)
    if key not in VALID_TYPES:
        raise ValueError(f"submission_type must be one of {sorted(VALID_TYPES)}")
    return key


def _missing(checks: list[dict[str, Any]], stages: set[str]) -> list[dict[str, Any]]:
    return [
        row for row in checks
        if row.get("status") == "Missing" and row.get("stage") in stages
    ]


def readiness_register(
    *,
    submission_type: str,
    has_model: bool,
    has_results: bool,
    has_pcswmm_package: bool,
    has_revision: bool,
    has_city_comments: bool,
    response_matrix: list[dict[str, Any]] | None = None,
    certified_checklist_attached: bool = False,
    no_objections_letter_attached: bool = False,
    prior_approved_report_attached: bool = False,
    correspondence_appendix_attached: bool = False,
    clean_copy: bool = False,
) -> dict[str, Any]:
    """Return draft, engineer-review, and final-submission readiness.

    The professional engineer-certified checklist is required for final municipal
    submission, but it does not block deterministic draft generation.
    """
    stype = normalize_submission_type(submission_type)
    checks: list[dict[str, Any]] = [
        {
            "check": "SWMM model available",
            "status": "Complete" if has_model else "Missing",
            "stage": "draft",
        },
        {
            "check": "Usable simulation results",
            "status": "Complete" if has_results else "Missing",
            "stage": "draft",
        },
        {
            "check": "Deterministic engineering evidence package",
            "status": "Complete" if has_pcswmm_package else "Missing",
            "stage": "draft",
        },
        {
            "check": "Professional engineer-certified SWMR checklist",
            "status": "Complete" if certified_checklist_attached else "Missing",
            "stage": "submission",
        },
    ]

    if stype in {"revised_submission", "final_submission"}:
        checks.extend([
            {
                "check": "Baseline-to-revised comparison",
                "status": "Complete" if has_revision else "Missing",
                "stage": "engineer_review",
            },
            {
                "check": "City review comments",
                "status": "Complete" if has_city_comments else "Missing",
                "stage": "engineer_review",
            },
        ])
        matrix = response_matrix or []
        unresolved = sum(
            1 for row in matrix
            if row.get("status") not in {"Resolved", "Not applicable"}
        )
        checks.append({
            "check": "Comment response closure",
            "status": "Complete" if matrix and unresolved == 0 else f"Review ({unresolved} unresolved)",
            "stage": "submission",
        })

    if stype == "final_submission":
        checks.extend([
            {
                "check": "Clean report copy without mark-ups",
                "status": "Complete" if clean_copy else "Missing",
                "stage": "submission",
            },
            {
                "check": "No Objections letter as first page",
                "status": "Complete" if no_objections_letter_attached else "Missing",
                "stage": "submission",
            },
            {
                "check": "Relevant correspondence appendix",
                "status": "Complete" if correspondence_appendix_attached else "Missing",
                "stage": "submission",
            },
        ])
        if has_revision:
            checks.append({
                "check": "Previously approved report included as appendix",
                "status": "Complete" if prior_approved_report_attached else "Missing",
                "stage": "submission",
            })

    draft_blocking = _missing(checks, {"draft"})
    review_blocking = _missing(checks, {"draft", "engineer_review"})
    submission_blocking = _missing(checks, {"draft", "engineer_review", "submission"})

    ready_for_draft = not draft_blocking
    ready_for_engineer_review = not review_blocking
    ready_for_submission = not submission_blocking

    if ready_for_submission:
        overall_status = "SUBMISSION READY"
    elif ready_for_engineer_review:
        overall_status = "ENGINEER-REVIEW READY"
    elif ready_for_draft:
        overall_status = "DRAFT READY"
    else:
        overall_status = "NOT READY"

    return {
        "submission_type": stype,
        "ready_for_draft": ready_for_draft,
        "ready_for_engineer_review": ready_for_engineer_review,
        "ready_for_submission": ready_for_submission,
        "status": overall_status,
        "checks": checks,
        "draft_blocking_items": [row["check"] for row in draft_blocking],
        "engineer_review_blocking_items": [row["check"] for row in review_blocking],
        "submission_blocking_items": [row["check"] for row in submission_blocking],
        # Backward compatibility for clients expecting blocking_items.
        "blocking_items": [row["check"] for row in submission_blocking],
        "disclaimer": (
            "Draft and engineer-review readiness indicate workflow completeness only. "
            "Final submission requires responsible professional authentication and City acceptance."
        ),
    }