"""Slack Bolt app — /oncall command handlers and interactive actions."""

import logging
import os
import re
from datetime import datetime, timedelta
from zoneinfo import ZoneInfo

from slack_bolt import App

from shared.blocks import (
    build_help_blocks,
    build_pay_summary_blocks,
    build_roster_blocks,
    build_shift_change_message,
    build_week_schedule,
)
from shared.ring_scheduler import update_ring_group
from shared.schedule import FALLBACK_EXTENSION, ShiftSchedule
from shared.secrets import get_secret

logger = logging.getLogger(__name__)
EASTERN = ZoneInfo("America/New_York")

DAY_NAMES = [
    "monday",
    "tuesday",
    "wednesday",
    "thursday",
    "friday",
    "saturday",
    "sunday",
]


def parse_date(text: str) -> datetime | None:
    """Parse flexible date input: today, tomorrow, day names, m/d, YYYY-MM-DD."""
    now = datetime.now(EASTERN)
    text = text.strip().lower()

    if text == "today":
        return now
    if text == "tomorrow":
        return now + timedelta(days=1)

    if text in DAY_NAMES:
        target = DAY_NAMES.index(text)
        current = now.weekday()
        delta = (target - current) % 7
        if delta == 0:
            delta = 7
        return now + timedelta(days=delta)

    for fmt in ("%Y-%m-%d", "%m/%d/%Y", "%m/%d", "%m-%d"):
        try:
            parsed = datetime.strptime(text, fmt)
            if "%Y" not in fmt:
                parsed = parsed.replace(year=now.year)
                if parsed.replace(tzinfo=EASTERN) < now - timedelta(days=1):
                    parsed = parsed.replace(year=now.year + 1)
            return parsed.replace(tzinfo=EASTERN)
        except ValueError:
            continue

    return None


def _update_3cx_routing(extension: str) -> None:
    """Update the 3CX ring group to forward calls to the given extension."""
    ring_group_number = os.environ.get("RING_GROUP_NUMBER")
    secret_prefix = os.environ.get("TCX_SECRET_PREFIX")
    if not ring_group_number or not secret_prefix:
        logger.warning("3CX env vars not set — skipping ring group update")
        return
    try:
        update_ring_group(
            extension=extension,
            ring_group_number=ring_group_number,
            domain=get_secret(f"{secret_prefix}domain"),
            client_id=get_secret(f"{secret_prefix}client-id"),
            client_secret=get_secret(f"{secret_prefix}client-secret"),
        )
    except Exception:
        logger.exception("Failed to update 3CX ring group")


def is_today(date_str: str) -> bool:
    return date_str == datetime.now(EASTERN).strftime("%Y-%m-%d")


def create_app(
    bot_token: str, signing_secret: str, schedule_channel: str | None = None
) -> App:
    app = App(
        token=bot_token,
        signing_secret=signing_secret,
        process_before_response=True,
    )
    schedule = ShiftSchedule()

    # ── /oncall command ─────────────────────────────────────────────────

    @app.command("/oncall")
    def handle_oncall(ack, command, respond, client):
        ack()
        text = (command.get("text") or "").strip()
        user_id = command["user_id"]
        channel_id = command["channel_id"]

        is_admin = user_id in schedule.get_admin_users()

        if not text or text == "schedule":
            _show_schedule(respond, schedule)
        elif text == "next":
            _show_next_week(respond, schedule)
        elif text == "help":
            respond(blocks=build_help_blocks(is_admin=is_admin))
        elif text == "roster":
            respond(blocks=build_roster_blocks(schedule.get_roster()))
        elif text == "pay":
            _show_pay(respond, schedule)
        elif text.startswith("rate"):
            _handle_rate(respond, schedule, text)
        elif text.startswith("register"):
            _handle_register(respond, schedule, user_id, text)
        elif text.startswith("pick"):
            _handle_pick(
                respond, schedule, user_id, text, schedule_channel or channel_id, client
            )
        elif text.startswith("drop"):
            _handle_drop(
                respond, schedule, user_id, text, schedule_channel or channel_id, client
            )
        elif text.startswith("swap"):
            _handle_swap(
                respond, schedule, user_id, text, schedule_channel or channel_id, client
            )
        elif text.startswith("admin"):
            _handle_admin(respond, schedule, user_id, text, is_admin, client)
        else:
            respond(text="Unknown command. Try `/oncall help`")

    # ── Interactive button: pick up open shift ──────────────────────────

    @app.action(re.compile(r"^pickup_"))
    def handle_pickup_button(ack, body, client, respond):
        ack()
        action_id = body["actions"][0]["action_id"]
        remainder = action_id.replace("pickup_", "")
        if remainder.endswith("_day"):
            date_str = remainder[:-4]
            shift_type = "day"
        else:
            date_str = remainder
            shift_type = "night"

        user_id = body["user"]["id"]
        channel_id = body["channel"]["id"]

        today_str = datetime.now(EASTERN).strftime("%Y-%m-%d")
        if date_str < today_str:
            client.chat_postEphemeral(
                channel=channel_id,
                user=user_id,
                text="That shift has already passed and can't be picked up.",
            )
            return

        employee = schedule.get_employee_by_slack_id(user_id)
        if not employee:
            client.chat_postEphemeral(
                channel=channel_id,
                user=user_id,
                text="You're not registered. Use `/oncall register <extension>` first.",
            )
            return

        claimed = schedule.claim_open_shift(
            date_str, employee["extension"], employee["name"], shift_type
        )
        if not claimed:
            client.chat_postEphemeral(
                channel=channel_id,
                user=user_id,
                text=f"That shift on *{date_str}* was already picked up by someone else.",
            )
            return

        if is_today(date_str) and shift_type == "night":
            _update_3cx_routing(employee["extension"])

        blocks = build_shift_change_message(
            user_id, date_str, "picked_up", employee["extension"], employee["name"],
            shift_type=shift_type,
        )
        respond(
            response_type="in_channel",
            replace_original=False,
            blocks=blocks,
            text=f"Shift picked up for {date_str}",
        )
        _refresh_schedule_post(client)

    def _refresh_schedule_post(client):
        """Update the pinned schedule message in-place after a shift change."""
        channel = schedule_channel
        if not channel:
            return
        post = schedule.get_schedule_post(channel)
        if not post or not post.get("message_ts"):
            return
        try:
            blocks = build_week_schedule(schedule)
            now = datetime.now(EASTERN)
            this_monday = now - timedelta(days=now.weekday())
            end_date = this_monday + timedelta(days=13)
            client.chat_update(
                channel=channel,
                ts=post["message_ts"],
                blocks=blocks,
                text=f"After-Hours Schedule — {now.strftime('%b %-d')} to {end_date.strftime('%b %-d')}",
            )
        except Exception:
            logger.warning("Could not update schedule post", exc_info=True)

    # ── Subcommand handlers ─────────────────────────────────────────────

    def _show_schedule(respond, schedule):
        blocks = build_week_schedule(schedule)
        respond(blocks=blocks)

    def _show_next_week(respond, schedule):
        now = datetime.now(EASTERN)
        # Jump 2 weeks ahead from this week's Monday
        this_monday = now - timedelta(days=now.weekday())
        next_start = this_monday + timedelta(days=14)
        blocks = build_week_schedule(schedule, start_date=next_start)
        respond(blocks=blocks)

    def _show_pay(respond, schedule):
        now = datetime.now(EASTERN)
        # Show last completed week's pay (previous Monday–Sunday)
        this_monday = now - timedelta(days=now.weekday())
        prev_monday = this_monday - timedelta(days=7)
        week_key = prev_monday.strftime("%Y-%m-%d")

        pay_record = schedule.get_pay_record(week_key)
        if pay_record and pay_record.get("breakdown"):
            prev_sunday = prev_monday + timedelta(days=6)
            week_label = (
                f"{prev_monday.strftime('%b %-d')} to {prev_sunday.strftime('%b %-d')}"
            )
            blocks = build_pay_summary_blocks(
                week_label, pay_record["breakdown"], pay_record["totals"]
            )
            respond(blocks=blocks)
        else:
            respond(
                text=f"No pay record found for the week of {prev_monday.strftime('%b %-d')}."
            )

    def _handle_rate(respond, schedule, text):
        parts = text.split()
        # /oncall rate — show current rates
        if len(parts) == 1:
            default_rate = schedule.get_shift_rate()
            roster = schedule.get_roster()
            lines = [f"*Default rate:* ${default_rate:.2f}/shift\n"]
            custom = [
                (e["SK"], e.get("name", "Unknown"), float(e["shift_rate"]))
                for e in roster
                if e.get("shift_rate")
            ]
            if custom:
                lines.append("*Per-person rates:*")
                for ext, name, rate in sorted(custom, key=lambda x: x[0]):
                    lines.append(f"• {name} (Ext {ext}) — ${rate:.2f}/shift")
            else:
                lines.append("_No per-person rates set — everyone uses the default._")
            respond(text="\n".join(lines))
            return

        # /oncall rate default <amount>
        if parts[1] == "default":
            if len(parts) < 3:
                respond(
                    text="Usage: `/oncall rate default <amount>`  (e.g. `/oncall rate default 50`)"
                )
                return
            try:
                amount = float(parts[2].replace("$", ""))
            except ValueError:
                respond(text=f"Invalid amount: `{parts[2]}`")
                return
            schedule.set_default_shift_rate(amount)
            respond(text=f"Default shift rate set to *${amount:.2f}*.")
            return

        # /oncall rate <extension> <amount>
        if len(parts) < 3:
            respond(
                text="Usage: `/oncall rate <extension> <amount>`  (e.g. `/oncall rate 114 75`)"
            )
            return

        ext = parts[1]
        employee = schedule.get_employee_by_extension(ext)
        if not employee:
            respond(text=f"Extension `{ext}` not found in the roster.")
            return

        try:
            amount = float(parts[2].replace("$", ""))
        except ValueError:
            respond(text=f"Invalid amount: `{parts[2]}`")
            return

        schedule.set_employee_shift_rate(ext, amount)
        respond(
            text=f"Shift rate for *{employee['name']}* (Ext {ext}) set to *${amount:.2f}*."
        )

    def _handle_register(respond, schedule, user_id, text):
        parts = text.split()
        if len(parts) < 2:
            respond(
                text="Usage: `/oncall register <extension>`  (e.g. `/oncall register 114`)"
            )
            return

        ext = parts[1].strip()
        employee = schedule.register_user(user_id, ext)
        if not employee:
            respond(
                text=f"Extension {ext} not found in the roster. Check `/oncall roster`."
            )
            return

        respond(text=f"Linked your account to *{employee['name']}* (Ext {ext}).")

    def _handle_pick(respond, schedule, user_id, text, channel_id, client):
        parts = text.split(maxsplit=1)
        if len(parts) < 2:
            respond(text="Usage: `/oncall pick <date>`  (e.g. `/oncall pick friday`)")
            return

        employee = schedule.get_employee_by_slack_id(user_id)
        if not employee:
            respond(
                text="You're not registered. Use `/oncall register <extension>` first."
            )
            return

        date = parse_date(parts[1])
        if not date:
            respond(
                text=f"Couldn't parse date: `{parts[1]}`. Try: today, tomorrow, friday, 4/5, 2026-04-05"
            )
            return

        date_str = date.strftime("%Y-%m-%d")
        if date_str < datetime.now(EASTERN).strftime("%Y-%m-%d"):
            respond(text="You can't pick up a shift in the past.")
            return

        day_name = date.strftime("%A")
        ext, name, source = schedule.resolve_shift(date_str, day_name)

        # Already assigned to someone else (not open)
        if source in ("weekly", "override") and ext != FALLBACK_EXTENSION:
            respond(
                text=f"That shift is already covered by {name} (Ext {ext}). They'd need to drop it first."
            )
            return

        schedule.set_override(date_str, employee["extension"], employee["name"])

        if is_today(date_str):
            _update_3cx_routing(employee["extension"])

        respond(text=f"You picked up the shift for *{date.strftime('%A, %b %-d')}*.")

        blocks = build_shift_change_message(
            user_id, date_str, "picked_up", employee["extension"], employee["name"]
        )
        try:
            client.chat_postMessage(
                channel=channel_id,
                blocks=blocks,
                text=f"Shift picked up for {date_str}",
            )
        except Exception:
            logger.exception("Failed to post pickup notification to channel")
        _refresh_schedule_post(client)

    def _handle_drop(respond, schedule, user_id, text, channel_id, client):
        parts = text.split(maxsplit=1)
        if len(parts) < 2:
            respond(text="Usage: `/oncall drop <date>`  (e.g. `/oncall drop friday`)")
            return

        employee = schedule.get_employee_by_slack_id(user_id)
        if not employee:
            respond(
                text="You're not registered. Use `/oncall register <extension>` first."
            )
            return

        date = parse_date(parts[1])
        if not date:
            respond(
                text=f"Couldn't parse date: `{parts[1]}`. Try: today, tomorrow, friday, 4/5, 2026-04-05"
            )
            return

        date_str = date.strftime("%Y-%m-%d")
        if date_str < datetime.now(EASTERN).strftime("%Y-%m-%d"):
            respond(text="You can't drop a shift in the past.")
            return

        day_name = date.strftime("%A")
        ext, name, source = schedule.resolve_shift(date_str, day_name)

        if ext != employee["extension"]:
            respond(text=f"That's not your shift — it belongs to {name} (Ext {ext}).")
            return

        schedule.mark_open(date_str)

        if is_today(date_str):
            _update_3cx_routing(FALLBACK_EXTENSION)

        respond(
            text=f"You dropped the shift for *{date.strftime('%A, %b %-d')}*. It's now open for pickup."
        )

        blocks = build_shift_change_message(user_id, date_str, "dropped", ext, name)
        try:
            client.chat_postMessage(
                channel=channel_id, blocks=blocks, text=f"Shift dropped for {date_str}"
            )
        except Exception:
            logger.exception("Failed to post drop notification to channel")
        _refresh_schedule_post(client)

    def _handle_swap(respond, schedule, user_id, text, channel_id, client):
        # Expected format: swap <date> @user  OR  swap <date> <extension>
        parts = text.split(maxsplit=2)
        if len(parts) < 3:
            respond(
                text="Usage: `/oncall swap <date> @person`  (e.g. `/oncall swap friday @sarah`)"
            )
            return

        employee = schedule.get_employee_by_slack_id(user_id)
        if not employee:
            respond(
                text="You're not registered. Use `/oncall register <extension>` first."
            )
            return

        date = parse_date(parts[1])
        if not date:
            respond(text=f"Couldn't parse date: `{parts[1]}`.")
            return

        date_str = date.strftime("%Y-%m-%d")
        day_name = date.strftime("%A")
        ext, name, source = schedule.resolve_shift(date_str, day_name)

        if ext != employee["extension"]:
            respond(
                text=f"That's not your shift — it belongs to {name} (Ext {ext}). You can only swap your own shifts."
            )
            return

        # Resolve target user — could be <@U12345> or an extension number
        target_text = parts[2].strip()
        slack_id_match = re.match(r"<@(\w+)(?:\|[^>]*)?>", target_text)
        if slack_id_match:
            target_slack_id = slack_id_match.group(1)
            target = schedule.get_employee_by_slack_id(target_slack_id)
            if not target:
                respond(
                    text=f"<@{target_slack_id}> isn't registered. They need to run `/oncall register <extension>`."
                )
                return
        else:
            target = schedule.get_employee_by_extension(target_text)
            if not target:
                respond(text=f"Extension `{target_text}` not found in the roster.")
                return

        schedule.set_override(date_str, target["extension"], target["name"])

        if is_today(date_str):
            _update_3cx_routing(target["extension"])

        blocks = build_shift_change_message(
            target.get("slack_user_id", user_id),
            date_str,
            "swapped",
            target["extension"],
            target["name"],
        )
        respond(
            text=f"Swapped *{date.strftime('%A, %b %-d')}* to {target['name']} (Ext {target['extension']})."
        )

        try:
            client.chat_postMessage(
                channel=channel_id, blocks=blocks, text=f"Shift swapped for {date_str}"
            )
        except Exception:
            logger.exception("Failed to post swap notification to channel")
        _refresh_schedule_post(client)

    def _handle_admin(respond, schedule, user_id, text, is_admin, client):
        if not is_admin:
            respond(text="Admin commands are restricted. Contact an administrator.")
            return

        parts = text.split()
        if len(parts) < 2:
            respond(
                text=(
                    "*Admin Commands:*\n"
                    "`admin override <date> <ext>` — Assign shift\n"
                    "`admin open <date>` — Mark open\n"
                    "`admin clear <date>` — Remove override\n"
                    "`admin roster add <ext> <name>` — Add employee\n"
                    "`admin roster remove <ext>` — Remove employee\n"
                    "`admin roster rename <ext> <name>` — Rename"
                )
            )
            return

        subcmd = parts[1]

        if subcmd == "override":
            if len(parts) < 4:
                respond(text="Usage: `/oncall admin override <date> <extension>`")
                return
            date = parse_date(parts[2])
            if not date:
                respond(text=f"Couldn't parse date: `{parts[2]}`")
                return
            ext = parts[3]
            employee = schedule.get_employee_by_extension(ext)
            if not employee:
                respond(text=f"Extension `{ext}` not found in the roster.")
                return
            date_str = date.strftime("%Y-%m-%d")
            schedule.set_override(date_str, employee["extension"], employee["name"])
            respond(
                text=f"Override set: *{date.strftime('%A, %b %-d')}* → {employee['name']} (Ext {ext})"
            )
            _refresh_schedule_post(client)

        elif subcmd == "open":
            if len(parts) < 3:
                respond(text="Usage: `/oncall admin open <date>`")
                return
            date = parse_date(parts[2])
            if not date:
                respond(text=f"Couldn't parse date: `{parts[2]}`")
                return
            date_str = date.strftime("%Y-%m-%d")
            schedule.mark_open(date_str)
            respond(text=f"*{date.strftime('%A, %b %-d')}* marked as open.")
            _refresh_schedule_post(client)

        elif subcmd == "clear":
            if len(parts) < 3:
                respond(text="Usage: `/oncall admin clear <date>`")
                return
            date = parse_date(parts[2])
            if not date:
                respond(text=f"Couldn't parse date: `{parts[2]}`")
                return
            date_str = date.strftime("%Y-%m-%d")
            schedule.remove_override(date_str)
            respond(
                text=f"Override cleared for *{date.strftime('%A, %b %-d')}* — reverted to weekly schedule."
            )
            _refresh_schedule_post(client)

        elif subcmd == "roster":
            if len(parts) < 3:
                respond(text="Usage: `admin roster add|remove|rename <ext> [name]`")
                return
            roster_cmd = parts[2]

            if roster_cmd == "add":
                if len(parts) < 5:
                    respond(text="Usage: `/oncall admin roster add <ext> <name>`")
                    return
                ext = parts[3]
                name = " ".join(parts[4:])
                schedule.add_roster_entry(ext, name)
                respond(text=f"Added *{name}* (Ext {ext}) to the roster.")

            elif roster_cmd == "remove":
                if len(parts) < 4:
                    respond(text="Usage: `/oncall admin roster remove <ext>`")
                    return
                ext = parts[3]
                employee = schedule.get_employee_by_extension(ext)
                if not employee:
                    respond(text=f"Extension `{ext}` not found in the roster.")
                    return
                schedule.remove_roster_entry(ext)
                respond(
                    text=f"Removed *{employee.get('name', ext)}* (Ext {ext}) from the roster."
                )

            elif roster_cmd == "rename":
                if len(parts) < 5:
                    respond(text="Usage: `/oncall admin roster rename <ext> <name>`")
                    return
                ext = parts[3]
                employee = schedule.get_employee_by_extension(ext)
                if not employee:
                    respond(text=f"Extension `{ext}` not found in the roster.")
                    return
                new_name = " ".join(parts[4:])
                schedule.rename_roster_entry(ext, new_name)
                respond(
                    text=f"Renamed Ext {ext}: {employee.get('name', '?')} → *{new_name}*"
                )

            else:
                respond(text="Unknown roster command. Use `add`, `remove`, or `rename`.")

        else:
            respond(text=f"Unknown admin command: `{subcmd}`. Try `/oncall help`.")

    return app