"""SCDMV Certificate of Compliance (COC) PDF filler.

The Certificate of Compliance is South Carolina's intrastate for-hire motor
carrier registration for PROPERTY carriers (everyone except passenger,
household-goods, and hazardous-waste-for-disposal carriers — those go to the
PSC instead). It is filed on SCDMV Form COC and mailed with a $25 fee to:

    SCDMV, P.O. Box 1498, Blythewood, SC 29016-0027

Two coverage classes:
  - E-L  : low-value commodities (dump-truck-type, scrap metal, etc.) — NO
           cargo insurance required (liability Form E only).
  - E-LC : property properly insured for any cargo — needs Form E + Form H.

The carrier's INSURANCE COMPANY (not agent) must file a Form E (liability) and,
if E-LC, a Form H (cargo) directly with SCDMV. SCDMV does NOT accept an ACORD
certificate. We collect the COC application + $25; the insurer files the Form E.

This module fills the official SCDMV Form COC from intake data. Field names in
the source PDF are partly auto-generated ('undefined', '1'..'6'); they are
mapped here by their verified on-page positions:
  undefined    -> Class E-L checkbox  (8x8 box, y=581)
  undefined_2  -> Class E-LC checkbox (8x8 box, y=520)
  '1'..'6'     -> officer/partner name+address lines
  Mailing Address (label is mis-assigned) -> PHYSICAL address line (y=159)
  undefined_3  -> mailing address line (y=137)
  Telephone Number / undefined_4 -> phone / fax

Usage:
    from scripts.document_gen.templates.sc_coc_pdf_filler import fill_sc_coc
    path = fill_sc_coc(intake, order_number="CO-...", coverage_class="E-L")
"""

from __future__ import annotations

import logging
import os
from pathlib import Path

LOG = logging.getLogger("document_gen.sc_coc")

try:
    from pypdf import PdfReader, PdfWriter
except ImportError:  # pragma: no cover
    try:
        from PyPDF2 import PdfReader, PdfWriter  # type: ignore
    except ImportError:
        PdfReader = PdfWriter = None  # type: ignore

DOCS_DIR = Path(__file__).resolve().parent.parent.parent.parent / "docs"
COC_FORM = DOCS_DIR / "SC COC Form.pdf"
OUTPUT_DIR = Path(os.getenv("DOC_OUTPUT_DIR", "/tmp/coc-filings"))

# Low-value commodities that SCDMV classifies as E-L (no cargo insurance). Scrap
# metal, dump-truck aggregates, etc. Used to auto-suggest the coverage class.
E_L_COMMODITY_HINTS = (
    "scrap", "metal", "dump", "aggregate", "gravel", "sand", "dirt", "rock",
    "debris", "waste" "recycl", "junk", "salvage", "demolition", "asphalt",
    "concrete", "mulch", "wood chip", "fill",
)


def suggest_coverage_class(intake: dict) -> str:
    """Best-effort E-L vs E-LC suggestion from the carrier's cargo description.
    Defaults to E-LC (the safer, fully-insured class) when unknown so we never
    under-state the insurance requirement."""
    cargo = " ".join(str(intake.get(k, "")) for k in
                      ("cargo_carried", "commodities", "commodity",
                       "cargo", "operation_description", "legal_name")).lower()
    if any(h in cargo for h in E_L_COMMODITY_HINTS):
        return "E-L"
    return "E-LC"


def _is_renewal(intake: dict) -> bool:
    return str(intake.get("coc_renewal", "")).lower() in ("yes", "true", "1") \
        or bool(intake.get("existing_coc_number"))


def fill_sc_coc(intake: dict, order_number: str = "",
                coverage_class: str | None = None) -> str:
    """Fill the SCDMV Form COC. Returns the path to the written PDF.

    coverage_class: 'E-L' or 'E-LC'. If None, auto-suggested from cargo.
    """
    if PdfReader is None:
        raise ImportError("pypdf not installed")
    if not COC_FORM.exists():
        raise FileNotFoundError(f"SC COC form not found: {COC_FORM}")

    coverage_class = (coverage_class or suggest_coverage_class(intake)).upper()
    reader = PdfReader(str(COC_FORM))
    writer = PdfWriter()
    writer.clone_document_from_reader(reader)

    legal_name = intake.get("legal_name") or intake.get("entity_name") or ""
    phys = ", ".join(p for p in [
        intake.get("address_street", "") or intake.get("phy_street", ""),
        intake.get("address_city", "") or intake.get("phy_city", ""),
        f"{intake.get('address_state','') or intake.get('phy_state','')} "
        f"{intake.get('address_zip','') or intake.get('phy_zip','')}".strip(),
    ] if p and p.strip())
    mailing = ", ".join(p for p in [
        intake.get("mailing_street", ""),
        intake.get("mailing_city", ""),
        f"{intake.get('mailing_state','')} {intake.get('mailing_zip','')}".strip(),
    ] if p and p.strip()) or phys

    # Officers / partners (up to 6 lines). Accept a list or single signer.
    officers = intake.get("officers") or []
    if not officers:
        signer = intake.get("signer_name") or ""
        if signer:
            officers = [f"{signer} - {phys}"]

    field_updates = {
        # Business identity (the source PDF splits the business-name label across
        # two text lines, suffixed " 1" / " 2"; put the name on line 1).
        "Business Name Corporation Partnership Sole Proprietorship With or Without Trade name 1":
            legal_name,
        # The form's text fields are auto-named after the label BELOW them, so the
        # names are offset by one. Mapped here by verified on-page geometry:
        #   "Mailing Address" field (y159, full width)  -> PHYSICAL address line
        #   "undefined_3" field (y137)                  -> MAILING address line
        #   "Fax Number" field (y80, x170)              -> TELEPHONE box
        #   "undefined_4" field (y80, x417)             -> FAX box
        "Mailing Address": phys,
        "undefined_3": mailing,
        "Fax Number": intake.get("phone", "") or intake.get("telephone", ""),
        "undefined_4": intake.get("fax", ""),
    }
    # Officer/partner lines 1..6
    for i, line in enumerate(officers[:6], start=1):
        field_updates[str(i)] = str(line)

    # Checkboxes: new vs renewal, and coverage class.
    button_updates = {}
    if _is_renewal(intake):
        button_updates["I am renewing an existing Certificate of Compliance I understand no fee is required for this submission"] = "/On"
    else:
        button_updates["I am applying for a Certificate of Compliance for the first time I understand that a 25 fee is required for initial"] = "/On"

    # Class E-L (undefined) vs E-LC (undefined_2). These are tiny text boxes in
    # the source, so we stamp an "X" into the right one.
    if coverage_class == "E-L":
        field_updates["undefined"] = "X"
    else:
        field_updates["undefined_2"] = "X"

    # Apply text fields (tolerant of name mismatches across PDF revisions).
    for page in writer.pages:
        try:
            writer.update_page_form_field_values(page, field_updates, auto_regenerate=False)
        except Exception as exc:  # noqa: BLE001
            LOG.debug("COC text fill page warning: %s", exc)
    # Apply radio/checkbox states.
    for page in writer.pages:
        try:
            writer.update_page_form_field_values(page, button_updates, auto_regenerate=False)
        except Exception:
            pass

    OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
    safe = (order_number or legal_name or "coc").replace("/", "_").replace(" ", "_")
    out = OUTPUT_DIR / f"SC_COC_{safe}.pdf"
    with open(out, "wb") as fh:
        writer.write(fh)
    LOG.info("[%s] Filled SC COC (%s) -> %s", order_number, coverage_class, out)
    return str(out)


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    demo = {
        "legal_name": "ALLENS SCRAP METAL LLC",
        "address_street": "3838 DANNY RD", "address_city": "LORIS",
        "address_state": "SC", "address_zip": "29569",
        "phone": "8435551234", "signer_name": "Mitchell Allen",
        "cargo_carried": "scrap metal",
    }
    p = fill_sc_coc(demo, order_number="CO-DEMO")
    print("wrote", p, "class:", suggest_coverage_class(demo))