#!/usr/bin/env python3
"""
Afmelden van mailinglijsten op basis van decisions.json.
Verwerkt List-Unsubscribe headers: HTTP (GET/POST) en mailto.

Gebruik: python3 unsubscribe.py
Log:     unsubscribe_log.json  (resultaat per lijst)
"""

import json
import re
import sys
import time
import smtplib
import ssl
import urllib.request
import urllib.parse
import urllib.error
import config
from email.mime.text import MIMEText
from pathlib import Path

DECISIONS_FILE   = Path(__file__).parent / "decisions.json"
LOG_FILE         = Path(__file__).parent / "unsubscribe_log.json"
REQUEST_TIMEOUT  = 10   # seconden per HTTP-verzoek
DELAY_BETWEEN    = 1.5  # seconden tussen verzoeken (beleefd)


# ── helpers ──────────────────────────────────────────────────────────────────

def parse_unsub_header(raw: str) -> dict[str, list[str]]:
    """
    Parseer List-Unsubscribe header naar {'http': [...], 'mailto': [...]}.
    Formaat: <url>, <url>, ...  (RFC 2369)
    """
    result = {"http": [], "mailto": []}
    for match in re.finditer(r"<([^>]+)>", raw):
        url = match.group(1).strip()
        if url.startswith("http"):
            result["http"].append(url)
        elif url.startswith("mailto:"):
            result["mailto"].append(url)
    return result


def try_http_unsub(url: str) -> tuple[bool, str]:
    """Probeer afmelden via HTTP GET. Geeft (succes, melding)."""
    try:
        req = urllib.request.Request(
            url,
            headers={"User-Agent": "Mozilla/5.0 (compatible; list-unsubscribe)"},
        )
        with urllib.request.urlopen(req, timeout=REQUEST_TIMEOUT) as resp:
            code = resp.getcode()
            return (code == 200), f"HTTP {code}"
    except urllib.error.HTTPError as e:
        return False, f"HTTP {e.code}"
    except Exception as e:
        return False, str(e)


def try_mailto_unsub(mailto: str, smtp: smtplib.SMTP, from_addr: str) -> tuple[bool, str]:
    """Stuur een lege e-mail naar het afmeldadres."""
    try:
        parsed = urllib.parse.urlparse(mailto)
        to_addr = parsed.path
        params  = urllib.parse.parse_qs(parsed.query)
        subject = params.get("subject", ["unsubscribe"])[0]

        msg = MIMEText("")
        msg["From"]    = from_addr
        msg["To"]      = to_addr
        msg["Subject"] = subject

        smtp.sendmail(from_addr, [to_addr], msg.as_string())
        return True, f"mailto verzonden → {to_addr}"
    except Exception as e:
        return False, str(e)


# ── main ──────────────────────────────────────────────────────────────────────

def run():
    if not DECISIONS_FILE.exists():
        print("decisions.json niet gevonden. Draai eerst review_mailinglists.py.")
        sys.exit(1)

    decisions = json.loads(DECISIONS_FILE.read_text(encoding="utf-8"))
    te_afmelden = {
        domain: info
        for domain, info in decisions.items()
        if isinstance(info, dict) and info.get("keuze") == "a"
        and info.get("unsubscribe")
    }
    handmatig = {
        domain: info
        for domain, info in decisions.items()
        if isinstance(info, dict) and info.get("keuze") == "a"
        and not info.get("unsubscribe")
    }

    print(f"Afmelden: {len(te_afmelden)} via List-Unsubscribe, "
          f"{len(handmatig)} handmatig (geen header).\n")

    # Laad bestaand log (herstart-safe)
    log: dict[str, dict] = {}
    if LOG_FILE.exists():
        try:
            log = json.loads(LOG_FILE.read_text(encoding="utf-8"))
            al_klaar = sum(1 for v in log.values() if v.get("succes"))
            print(f"Bestaand log geladen: {al_klaar} al verwerkt.\n")
        except Exception:
            pass

    cfg = config.load()

    # SMTP verbinding voor mailto-afmeldingen
    smtp = None
    heeft_mailto = any(
        any(u.startswith("mailto:") for u in info.get("unsubscribe", []))
        for info in te_afmelden.values()
    )
    if heeft_mailto:
        print(f"Sommige afmeldingen gaan via e-mail (mailto:). Account: {cfg.username}")
        try:
            context = ssl.create_default_context()
            smtp = smtplib.SMTP(cfg.smtp_host, cfg.smtp_port)
            smtp.starttls(context=context)
            smtp.login(cfg.username, cfg.password)
            print("SMTP verbonden.\n")
        except Exception as e:
            print(f"SMTP mislukt: {e}\n  mailto-afmeldingen worden overgeslagen.")
            smtp = None

    # Verwerk afmeldingen
    total = len(te_afmelden)
    for idx, (domain, info) in enumerate(te_afmelden.items(), 1):
        naam = info.get("naam", domain)

        if domain in log and log[domain].get("succes"):
            print(f"[{idx}/{total}] {naam} — al afgemeld, overgeslagen.")
            continue

        print(f"[{idx}/{total}] {naam} ({domain})")
        succes = False
        methode = ""
        melding = ""

        for raw_unsub in info.get("unsubscribe", []):
            parsed = parse_unsub_header(raw_unsub)

            # Probeer HTTP eerst
            for url in parsed["http"]:
                ok, msg = try_http_unsub(url)
                if ok:
                    succes  = True
                    methode = "HTTP GET"
                    melding = f"{msg} → {url[:80]}"
                    break
                else:
                    melding = f"{msg} → {url[:60]}"

            if succes:
                break

            # Dan mailto
            if smtp:
                for mailto in parsed["mailto"]:
                    ok, msg = try_mailto_unsub(mailto, smtp, cfg.username)
                    if ok:
                        succes  = True
                        methode = "mailto"
                        melding = msg
                        break

            if succes:
                break

        status = "✓" if succes else "✗"
        print(f"  {status} {methode or 'mislukt'}  {melding}")

        log[domain] = {
            "naam":    naam,
            "succes":  succes,
            "methode": methode,
            "melding": melding,
        }
        LOG_FILE.write_text(json.dumps(log, indent=2, ensure_ascii=False), encoding="utf-8")

        time.sleep(DELAY_BETWEEN)

    if smtp:
        smtp.quit()

    # Samenvatting
    gelukt  = sum(1 for v in log.values() if v.get("succes"))
    mislukt = sum(1 for v in log.values() if not v.get("succes"))

    print(f"\n{'─'*50}")
    print(f"Klaar. {gelukt} afgemeld, {mislukt} mislukt.")

    if mislukt:
        print("\nMislukt (handmatig afmelden):")
        for domain, v in log.items():
            if not v.get("succes"):
                print(f"  {v['naam']}  ({domain})")

    if handmatig:
        print(f"\nGeen List-Unsubscribe header gevonden ({len(handmatig)}) — handmatig afmelden:")
        for domain, info in handmatig.items():
            print(f"  {info.get('naam', domain)}  ({domain})")

    print(f"\nLog opgeslagen in: {LOG_FILE}")


if __name__ == "__main__":
    run()