"""
Orchestrator step functions.

Each step receives a WeeklyRun row and an open Session. Steps are idempotent:
a non-null timestamp column causes an immediate return. Steps commit their own
changes before returning.

All service imports are at module level so tests can monkeypatch via
`app.services.orchestrator.steps.<name>`.
"""
from __future__ import annotations

import logging
from datetime import datetime, timezone
from typing import TYPE_CHECKING

from app.config import settings
from app.models import FamilyMember, FamilyProfile, MealPlan, MealPlanItemStatus
from app.services.approval import issue_token
from app.services.email import get_email_backend
from app.services.orchestrator.alerts import send_admin_alert
from app.services.planner.generate import generate_meal_plan
from app.services.scraper_service import ScraperService

if TYPE_CHECKING:
    from sqlalchemy.orm import Session
    from app.models import WeeklyRun

logger = logging.getLogger(__name__)


def step_scrape(run: "WeeklyRun", db: "Session") -> None:
    if run.scraped_at is not None:
        logger.info("step_scrape: already done for %s, skipping", run.week_start_date)
        return

    service = ScraperService(db)
    last_result: dict = {}
    for attempt in (1, 2):
        last_result = service.run_scrape()
        if last_result["status"] == "success":
            run.scraped_at = datetime.now(timezone.utc)
            run.used_stale_data = False
            db.commit()
            logger.info("step_scrape: success on attempt %d", attempt)
            return
        logger.warning(
            "step_scrape: attempt %d failed: %s", attempt, last_result.get("error")
        )

    # Both attempts failed — mark stale and continue the cycle
    run.scraped_at = datetime.now(timezone.utc)
    run.used_stale_data = True
    db.commit()
    send_admin_alert(
        subject=f"Scrape failed week {run.week_start_date}",
        body=(
            f"Both scrape attempts failed. Proceeding with stale grocery data.\n"
            f"Error: {last_result.get('error')}"
        ),
    )
    logger.warning("step_scrape: both attempts failed; marked stale")


def step_generate(run: "WeeklyRun", db: "Session") -> None:
    if run.generated_at is not None:
        logger.info("step_generate: already done for %s", run.week_start_date)
        return

    try:
        result = generate_meal_plan(
            db,
            family_id=run.family_id,
            week_start_date=run.week_start_date,
        )
        run.generated_at = datetime.now(timezone.utc)
        db.commit()
        logger.info("step_generate: meal_plan %s created", result.meal_plan_id)
    except Exception as exc:
        run.error_step = "generate"
        run.error_message = str(exc)
        db.commit()
        send_admin_alert(
            subject=f"Generate failed week {run.week_start_date}",
            body=str(exc),
        )
        raise


def step_email(run: "WeeklyRun", db: "Session") -> None:
    if run.emailed_at is not None:
        logger.info("step_email: already done for %s", run.week_start_date)
        return

    plan = (
        db.query(MealPlan)
        .filter(
            MealPlan.family_profile_id == run.family_id,
            MealPlan.week_start_date == run.week_start_date,
        )
        .first()
    )
    if plan is None:
        raise RuntimeError(
            f"No MealPlan for family {run.family_id} week {run.week_start_date}"
        )

    members = (
        db.query(FamilyMember)
        .filter(
            FamilyMember.family_profile_id == run.family_id,
            FamilyMember.email.isnot(None),
        )
        .all()
    )

    stale_banner = ""
    if run.used_stale_data:
        stale_banner = (
            "<p><strong>Note:</strong> Grocery prices in this plan may be a few "
            "days old — the Friday scrape failed and stale data was used.</p>"
        )

    backend = get_email_backend()
    for member in members:
        item_html_parts = []
        for item in plan.items:
            if item.approval_status != MealPlanItemStatus.PENDING:
                continue
            token = issue_token(item.id, member.id)
            vote_url = (
                f"{settings.APP_BASE_URL}/api/meals/vote/{item.id}?token={token}"
            )
            recipe_name = item.recipe.name if item.recipe else str(item.recipe_id)
            item_html_parts.append(
                f'<li>{recipe_name} — <a href="{vote_url}">Vote</a></li>'
            )

        if not item_html_parts:
            continue

        html = (
            f"<h2>This week's meal suggestions</h2>"
            f"{stale_banner}"
            f"<p>Hi {member.name}, please vote on this week's meals by Fri 17:00 PT:</p>"
            f"<ul>{''.join(item_html_parts)}</ul>"
            f"<p>Silence = approved. Any denial removes that meal.</p>"
        )
        backend.send(
            to=member.email,
            subject=f"Meal plan for week of {run.week_start_date}",
            html=html,
        )
        logger.info("step_email: sent to %s", member.email)

    run.emailed_at = datetime.now(timezone.utc)
    db.commit()


def step_deadline(run: "WeeklyRun", db: "Session") -> None:
    if run.deadline_passed_at is not None:
        logger.info("step_deadline: already done for %s", run.week_start_date)
        return

    plan = (
        db.query(MealPlan)
        .filter(
            MealPlan.family_profile_id == run.family_id,
            MealPlan.week_start_date == run.week_start_date,
        )
        .first()
    )
    if plan is None:
        run.deadline_passed_at = datetime.now(timezone.utc)
        db.commit()
        return

    family = db.query(FamilyProfile).filter(FamilyProfile.id == run.family_id).first()
    policy = getattr(family, "pending_approval_policy", "approve") if family else "approve"

    resolved = 0
    for item in plan.items:
        if item.approval_status == MealPlanItemStatus.PENDING:
            item.approval_status = (
                MealPlanItemStatus.APPROVED
                if policy == "approve"
                else MealPlanItemStatus.DENIED
            )
            resolved += 1

    run.deadline_passed_at = datetime.now(timezone.utc)
    db.commit()
    logger.info(
        "step_deadline: resolved %d pending items with policy=%s", resolved, policy
    )


def step_finalize(run: "WeeklyRun", db: "Session") -> None:
    if run.finalized_at is not None:
        logger.info("step_finalize: already done for %s", run.week_start_date)
        return

    plan = (
        db.query(MealPlan)
        .filter(
            MealPlan.family_profile_id == run.family_id,
            MealPlan.week_start_date == run.week_start_date,
        )
        .first()
    )

    approved_items = [
        item
        for item in (plan.items if plan else [])
        if item.approval_status == MealPlanItemStatus.APPROVED
    ]

    members = (
        db.query(FamilyMember)
        .filter(
            FamilyMember.family_profile_id == run.family_id,
            FamilyMember.email.isnot(None),
        )
        .all()
    )

    if approved_items:
        rows_html = "".join(
            f"<tr><td>{item.recipe.name}</td>"
            f"<td>{ing.get('name', '')}</td>"
            f"<td>{ing.get('qty', '')} {ing.get('unit', '')}</td></tr>"
            for item in approved_items
            if item.recipe
            for ing in (item.recipe.ingredients or [])
        )
        html = (
            f"<h2>Shopping list — week of {run.week_start_date}</h2>"
            f"<p>{len(approved_items)} meal(s) approved.</p>"
            f"<table><thead><tr><th>Recipe</th><th>Ingredient</th><th>Qty</th></tr></thead>"
            f"<tbody>{rows_html}</tbody></table>"
        )
    else:
        html = f"<p>No meals were approved for week of {run.week_start_date}.</p>"

    backend = get_email_backend()
    for member in members:
        backend.send(
            to=member.email,
            subject=f"Shopping list — week of {run.week_start_date}",
            html=html,
        )
        logger.info("step_finalize: shopping list sent to %s", member.email)

    run.finalized_at = datetime.now(timezone.utc)
    run.status = "completed"
    db.commit()
    logger.info("step_finalize: done, %d approved meals", len(approved_items))