"""Generate the state-trucking "Limited Authorization to File" PDF.

This is the signed authorization the customer must provide before Performance
West can file state motor-carrier compliance documents on their behalf (NY HUT,
CT HUF, OR Weight-Mile, CA MCP/CARB, KY KYU, NM WDT, IRP/IFTA, etc.). See
docs/trucking-state-authorization-plan.md.

The generator draws an explicit signature line and records its exact PDF
coordinates via :func:`signature_box`, so the e-signature stamper can place the
client's signature precisely on that line (see signature_stamper.py).

Returns ``(pdf_bytes, anchors)`` where ``anchors`` is the list to persist in
``esign_records.signature_anchors``.
"""
from __future__ import annotations

import io
import logging
from datetime import datetime, timezone
from typing import Any

try:  # normal import when loaded as part of the services package
    from .signature_stamper import signature_box
except ImportError:  # pragma: no cover - standalone/CLI use
    from signature_stamper import signature_box  # type: ignore

LOG = logging.getLogger("workers.services.state_trucking_authorization")

NAVY = "#0b1f3a"
SLATE = "#475569"
RULE = "#94a3b8"

_AUTH_BODY = (
    "By signing below, the Customer named above authorizes Performance West Inc. "
    "(\"Performance West\") to act as its limited agent to:"
)

_AUTH_GRANTS = [
    "prepare, review, submit, and amend the state motor carrier compliance "
    "filing(s) identified in this authorization;",
    "access state agency portals or tax systems where representative, "
    "practitioner, bulk-filer, or delegate access is available;",
    "communicate with state agencies about the filing and receive filing status, "
    "notices, confirmations, decals, credentials, and deficiency messages;",
    "coordinate with the Customer's insurer or insurance agent for any required "
    "insurance filings;",
    "remit government fees, taxes, card processing fees, decals, permits, bonds, "
    "and pass-through charges when collected from the Customer;",
    "retain a copy of this signed authorization for agency audit or request "
    "purposes.",
]

_AUTH_ACK = [
    "The Customer remains responsible for the accuracy and completeness of the "
    "information it provides.",
    "Government fees, taxes, card processing fees, bonds/security, decals, "
    "permits, and insurance filing costs are pass-through charges and may be "
    "billed separately if not known at the time of order.",
    "Some state filings require the Customer to grant portal access/delegation or "
    "approve account changes; Performance West will request this where needed.",
    "This authorization is limited to the filing(s) listed and may be revoked in "
    "writing, except as to filings already submitted.",
]


def build_state_trucking_authorization(
    *,
    order_number: str,
    entity_name: str,
    service_name: str,
    dot_number: str = "",
    mc_number: str = "",
    fein_last4: str = "",
    base_state: str = "",
    operating_states: list[str] | None = None,
    signer_name: str = "",
    signer_title: str = "",
) -> tuple[bytes, list[dict[str, Any]]]:
    """Render the authorization PDF and return (pdf_bytes, signature_anchors)."""
    from reportlab.lib.colors import HexColor
    from reportlab.lib.pagesizes import letter
    from reportlab.lib.units import inch
    from reportlab.pdfgen import canvas

    buf = io.BytesIO()
    page_w, page_h = letter  # 612 x 792
    c = canvas.Canvas(buf, pagesize=letter)

    left = 0.85 * inch
    right = page_w - 0.85 * inch
    width = right - left

    def wrap(text: str, font: str, size: float, max_w: float) -> list[str]:
        c.setFont(font, size)
        words = text.split()
        lines: list[str] = []
        cur = ""
        for w in words:
            trial = (cur + " " + w).strip()
            if c.stringWidth(trial, font, size) <= max_w:
                cur = trial
            else:
                if cur:
                    lines.append(cur)
                cur = w
        if cur:
            lines.append(cur)
        return lines

    y = page_h - 0.9 * inch

    # Header
    c.setFillColor(HexColor(NAVY))
    c.setFont("Helvetica-Bold", 16)
    c.drawString(left, y, "Performance West Inc.")
    y -= 18
    c.setFont("Helvetica", 9.5)
    c.setFillColor(HexColor(SLATE))
    c.drawString(left, y, "DOT / State Motor Carrier Compliance Division  |  (888) 411-0383  |  performancewest.net")
    y -= 8
    c.setStrokeColor(HexColor(RULE))
    c.line(left, y, right, y)
    y -= 26

    c.setFillColor(HexColor(NAVY))
    c.setFont("Helvetica-Bold", 13.5)
    c.drawString(left, y, "Limited Authorization to File State Motor Carrier Compliance Documents")
    y -= 22

    # Customer / order block
    def field_row(label: str, value: str) -> None:
        nonlocal y
        c.setFont("Helvetica-Bold", 10)
        c.setFillColor(HexColor(NAVY))
        c.drawString(left, y, label)
        c.setFont("Helvetica", 10)
        c.setFillColor(HexColor("#1f2937"))
        c.drawString(left + 1.6 * inch, y, value or "—")
        y -= 15

    states = ", ".join(operating_states or []) if operating_states else (base_state or "—")
    field_row("Customer (Carrier):", entity_name)
    field_row("USDOT #:", dot_number)
    if mc_number:
        field_row("MC/MX/FF #:", mc_number)
    if fein_last4:
        field_row("FEIN (last 4):", fein_last4)
    field_row("Covered filing:", service_name)
    field_row("Covered state(s):", states)
    field_row("Order #:", order_number)
    y -= 8

    # Body intro
    c.setFillColor(HexColor("#1f2937"))
    for ln in wrap(_AUTH_BODY, "Helvetica", 10, width):
        c.setFont("Helvetica", 10)
        c.drawString(left, y, ln)
        y -= 14
    y -= 4

    # Numbered grants
    for i, grant in enumerate(_AUTH_GRANTS, 1):
        bullet = f"{i}."
        c.setFont("Helvetica-Bold", 10)
        c.drawString(left, y, bullet)
        lines = wrap(grant, "Helvetica", 10, width - 0.3 * inch)
        for j, ln in enumerate(lines):
            c.setFont("Helvetica", 10)
            c.drawString(left + 0.3 * inch, y, ln)
            y -= 13
        y -= 3

    y -= 6
    c.setFont("Helvetica-Bold", 10.5)
    c.setFillColor(HexColor(NAVY))
    c.drawString(left, y, "Acknowledgements")
    y -= 16
    for ack in _AUTH_ACK:
        c.setFillColor(HexColor("#475569"))
        c.setFont("Helvetica", 9.5)
        c.drawString(left, y, "\u2022")
        for j, ln in enumerate(wrap(ack, "Helvetica", 9.5, width - 0.25 * inch)):
            c.drawString(left + 0.25 * inch, y, ln)
            y -= 12
        y -= 2

    # ── Signature block ──────────────────────────────────────────────
    # Reserve a fixed band near the bottom so the signature line position is
    # deterministic. The signature box sits ON TOP of the rule.
    sig_rule_y = 1.55 * inch
    sig_box_h = 42.0
    sig_box_w = 3.1 * inch
    sig_x = left

    c.setFillColor(HexColor(NAVY))
    c.setFont("Helvetica-Bold", 10.5)
    c.drawString(left, sig_rule_y + sig_box_h + 14, "Authorized Signature")

    # The signature rule
    c.setStrokeColor(HexColor("#334155"))
    c.setLineWidth(1)
    c.line(sig_x, sig_rule_y, sig_x + sig_box_w, sig_rule_y)

    # Date rule to the right
    date_x = sig_x + sig_box_w + 0.5 * inch
    date_w = right - date_x
    c.line(date_x, sig_rule_y, right, sig_rule_y)

    c.setFont("Helvetica", 8.5)
    c.setFillColor(HexColor(SLATE))
    c.drawString(sig_x, sig_rule_y - 11, "Signature")
    c.drawString(date_x, sig_rule_y - 11, "Date")

    # Printed name / title beneath
    ny = sig_rule_y - 30
    c.setFont("Helvetica", 9.5)
    c.setFillColor(HexColor("#1f2937"))
    c.drawString(sig_x, ny, f"Printed name: {signer_name or '________________________'}")
    c.drawString(date_x, ny, f"Title: {signer_title or '____________'}")

    # Footer note
    c.setFont("Helvetica-Oblique", 7.5)
    c.setFillColor(HexColor("#94a3b8"))
    c.drawString(
        left,
        0.75 * inch,
        f"Generated {datetime.now(timezone.utc).strftime('%Y-%m-%d %H:%M UTC')}  |  "
        f"Order {order_number}  |  Performance West Inc.",
    )

    c.save()
    buf.seek(0)
    pdf_bytes = buf.getvalue()

    # Record the exact signature box so the stamper lands the signature on the
    # rule. The box bottom == the rule's y, height extends upward.
    anchors = [
        signature_box(
            field="signer",
            page=0,
            x=sig_x + 4,            # small inset from the line's left end
            y=sig_rule_y + 1,       # rest the signature just on top of the rule
            w=sig_box_w - 8,
            h=sig_box_h,
            page_w=page_w,
            page_h=page_h,
        ),
        signature_box(
            field="date",
            page=0,
            x=date_x + 4,
            y=sig_rule_y + 1,
            w=date_w - 8,
            h=20.0,
            page_w=page_w,
            page_h=page_h,
        ),
    ]
    return pdf_bytes, anchors


if __name__ == "__main__":  # quick local render for visual verification
    pdf, anchors = build_state_trucking_authorization(
        order_number="CO-TEST1234",
        entity_name="Acme Freight LLC",
        service_name="New York Highway Use Tax (HUT) Registration",
        dot_number="3456789",
        mc_number="MC-987654",
        fein_last4="1234",
        base_state="NY",
        operating_states=["NY", "PA", "OH"],
        signer_name="John Smith",
        signer_title="Owner",
    )
    with open("/tmp/state_trucking_authorization.pdf", "wb") as f:
        f.write(pdf)
    print("wrote /tmp/state_trucking_authorization.pdf")
    print("anchors:", anchors)