"""REST API for Mindbaboon.

All endpoints require an API key in the `X-API-Key` header matching the
`MINDBABOON_API_KEY` environment variable. Returns JSON only.
"""
from functools import wraps
from datetime import datetime
import os
import socket
import secrets
import logging

from flask import Blueprint, request, jsonify

from database import (
    get_db_connection,
    get_iteration_slot,
    set_iteration_slot,
    get_setting,
    set_setting,
)
from config import ITERATION_INTERVALS, VERSION
from scheduler import (
    scheduler,
    schedule_reminder,
    remove_reminder,
    get_next_run_for_goal,
    reschedule_all_active,
)

WEEKDAY_NAMES = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]

logger = logging.getLogger(__name__)

api_bp = Blueprint("api", __name__, url_prefix="/api")

VALID_ITERATIONS = set(ITERATION_INTERVALS.keys())
VALID_TIME_SPANS = {"weeks", "months", "specific_date"}
REQUIRED_GOAL_FIELDS = ("goal_name", "goal_description", "time_span",
                       "iteration", "next_steps", "reward")


def _validate_goal_payload(data):
    """Return error dict or None. All six user-facing fields must be present
    and non-empty; time_span=specific_date requires end_date (YYYY-MM-DD)."""
    if not isinstance(data, dict):
        return {"error": "Body must be a JSON object"}
    missing = [f for f in REQUIRED_GOAL_FIELDS
               if not str(data.get(f, "")).strip()]
    if missing:
        return {"error": "missing required fields",
                "missing": missing,
                "required": list(REQUIRED_GOAL_FIELDS)}
    if data["time_span"] not in VALID_TIME_SPANS:
        return {"error": f"time_span must be one of {sorted(VALID_TIME_SPANS)}"}
    if data["iteration"] not in VALID_ITERATIONS:
        return {"error": f"iteration must be one of {sorted(VALID_ITERATIONS)}"}
    if data["time_span"] == "specific_date":
        ed = str(data.get("end_date", "")).strip()
        try:
            datetime.strptime(ed, "%Y-%m-%d")
        except ValueError:
            return {"error": "end_date (YYYY-MM-DD) is required when time_span=specific_date"}
    return None


def require_api_key(view):
    @wraps(view)
    def wrapper(*args, **kwargs):
        expected = os.getenv("MINDBABOON_API_KEY")
        if not expected:
            return jsonify({"error": "API disabled: MINDBABOON_API_KEY not set"}), 503
        provided = request.headers.get("X-API-Key", "")
        if not secrets.compare_digest(provided, expected):
            return jsonify({"error": "Unauthorized"}), 401
        return view(*args, **kwargs)
    return wrapper


def goal_to_dict(row):
    d = dict(row)
    d["next_run"] = get_next_run_for_goal(d["id"])
    return d


@api_bp.route("/health", methods=["GET"])
def health():
    conn = get_db_connection()
    try:
        goal_count = conn.execute("SELECT COUNT(*) AS c FROM goals").fetchone()["c"]
        active_count = conn.execute(
            "SELECT COUNT(*) AS c FROM goals WHERE completed = 0"
        ).fetchone()["c"]
        job_rows = conn.execute(
            "SELECT id, next_run_time FROM apscheduler_jobs ORDER BY next_run_time ASC"
        ).fetchall()
    finally:
        conn.close()

    jobs = [
        {
            "id": r["id"],
            "next_run_time": datetime.fromtimestamp(r["next_run_time"]).isoformat()
            if r["next_run_time"]
            else None,
        }
        for r in job_rows
    ]
    return jsonify(
        {
            "status": "ok",
            "version": VERSION,
            "pid": os.getpid(),
            "hostname": socket.gethostname(),
            "scheduler_running": scheduler.running,
            "goals_total": goal_count,
            "goals_active": active_count,
            "scheduled_jobs": len(jobs),
            "jobs": jobs,
            "valid_iterations": sorted(VALID_ITERATIONS),
        }
    )


@api_bp.route("/goals", methods=["GET"])
@require_api_key
def list_goals():
    include_completed = request.args.get("include_completed", "false").lower() == "true"
    conn = get_db_connection()
    try:
        if include_completed:
            rows = conn.execute("SELECT * FROM goals ORDER BY created_at DESC").fetchall()
        else:
            rows = conn.execute(
                "SELECT * FROM goals WHERE completed = 0 ORDER BY created_at DESC"
            ).fetchall()
    finally:
        conn.close()
    return jsonify([goal_to_dict(r) for r in rows])


@api_bp.route("/goals/<int:goal_id>", methods=["GET"])
@require_api_key
def get_goal(goal_id):
    conn = get_db_connection()
    try:
        row = conn.execute("SELECT * FROM goals WHERE id = ?", (goal_id,)).fetchone()
    finally:
        conn.close()
    if not row:
        return jsonify({"error": "Goal not found"}), 404
    return jsonify(goal_to_dict(row))


@api_bp.route("/goals", methods=["POST"])
@require_api_key
def create_goal():
    data = request.get_json(silent=True) or {}
    err = _validate_goal_payload(data)
    if err:
        return jsonify(err), 400

    goal_name = data["goal_name"].strip()
    iteration = data["iteration"]
    goal_description = data["goal_description"]
    time_span = data["time_span"]
    end_date = data["end_date"] if time_span == "specific_date" else None
    next_steps = data["next_steps"]
    reward = data["reward"]

    conn = get_db_connection()
    try:
        cur = conn.cursor()
        cur.execute(
            """
            INSERT INTO goals (
                goal_name, goal_description, time_span, end_date,
                iteration, next_steps, reward, completed, created_at, last_reminder_at
            ) VALUES (?, ?, ?, ?, ?, ?, ?, 0, ?, NULL)
            """,
            (
                goal_name,
                goal_description,
                time_span,
                end_date,
                iteration,
                next_steps,
                reward,
                datetime.now(),
            ),
        )
        conn.commit()
        goal_id = cur.lastrowid
        row = conn.execute("SELECT * FROM goals WHERE id = ?", (goal_id,)).fetchone()
    finally:
        conn.close()

    schedule_reminder(goal_id, iteration)

    return jsonify(goal_to_dict(row)), 201


@api_bp.route("/goals/<int:goal_id>", methods=["PATCH", "PUT"])
@require_api_key
def update_goal(goal_id):
    """Full-form update. All six fields required, same as creating a goal —
    so nothing silently drops. For state toggles use the /snooze, /resume,
    /complete endpoints instead."""
    data = request.get_json(silent=True) or {}
    err = _validate_goal_payload(data)
    if err:
        return jsonify(err), 400

    conn = get_db_connection()
    try:
        row = conn.execute("SELECT * FROM goals WHERE id = ?", (goal_id,)).fetchone()
        if not row:
            return jsonify({"error": "Goal not found"}), 404

        end_date = data["end_date"] if data["time_span"] == "specific_date" else None
        iteration_changed = data["iteration"] != row["iteration"]

        conn.execute(
            """
            UPDATE goals SET
                goal_name = ?, goal_description = ?, time_span = ?, end_date = ?,
                iteration = ?, next_steps = ?, reward = ?
            WHERE id = ?
            """,
            (
                data["goal_name"].strip(),
                data["goal_description"],
                data["time_span"],
                end_date,
                data["iteration"],
                data["next_steps"],
                data["reward"],
                goal_id,
            ),
        )
        conn.commit()
        row = conn.execute("SELECT * FROM goals WHERE id = ?", (goal_id,)).fetchone()
    finally:
        conn.close()

    if iteration_changed:
        remove_reminder(goal_id)
        schedule_reminder(goal_id, data["iteration"], send_confirmation=False)

    return jsonify(goal_to_dict(row))


@api_bp.route("/goals/<int:goal_id>", methods=["DELETE"])
@require_api_key
def delete_goal(goal_id):
    conn = get_db_connection()
    try:
        row = conn.execute("SELECT id FROM goals WHERE id = ?", (goal_id,)).fetchone()
        if not row:
            return jsonify({"error": "Goal not found"}), 404
        # FK ON DELETE CASCADE removes child rows from goal_history and
        # iteration_history; see database.py for the pragma.
        conn.execute("DELETE FROM goals WHERE id = ?", (goal_id,))
        conn.commit()
    finally:
        conn.close()
    remove_reminder(goal_id)
    return jsonify({"deleted": goal_id})


@api_bp.route("/goals/<int:goal_id>/complete", methods=["POST"])
@require_api_key
def complete_goal(goal_id):
    data = request.get_json(silent=True) or {}
    was_done = data.get("was_done", "")
    next_steps = data.get("next_steps")
    reward = data.get("reward")
    mark_done = bool(data.get("mark_done", False))

    conn = get_db_connection()
    try:
        row = conn.execute("SELECT * FROM goals WHERE id = ?", (goal_id,)).fetchone()
        if not row:
            return jsonify({"error": "Goal not found"}), 404

        new_next_steps = next_steps if next_steps is not None else row["next_steps"]
        new_reward = reward if reward is not None else row["reward"]

        conn.execute(
            """
            INSERT INTO iteration_history (iteration_id, status, updated_at)
            VALUES (?, ?, ?)
            """,
            (goal_id, "Yes", datetime.now()),
        )
        conn.execute(
            """
            INSERT INTO goal_history (goal_id, completed, was_done, next_steps, reward, timestamp)
            VALUES (?, ?, ?, ?, ?, ?)
            """,
            (goal_id, "yes", was_done, new_next_steps, new_reward, datetime.now()),
        )
        conn.execute(
            """
            UPDATE goals SET next_steps = ?, reward = ?, completed = ?, is_silenced = 0
            WHERE id = ?
            """,
            (new_next_steps, new_reward, 1 if mark_done else row["completed"], goal_id),
        )
        conn.commit()
    finally:
        conn.close()

    if mark_done:
        remove_reminder(goal_id)

    return jsonify({"ok": True, "goal_id": goal_id, "marked_done": mark_done})


@api_bp.route("/goals/<int:goal_id>/snooze", methods=["POST"])
@require_api_key
def snooze_goal(goal_id):
    conn = get_db_connection()
    try:
        row = conn.execute("SELECT id FROM goals WHERE id = ?", (goal_id,)).fetchone()
        if not row:
            return jsonify({"error": "Goal not found"}), 404
        conn.execute("UPDATE goals SET is_silenced = 1 WHERE id = ?", (goal_id,))
        conn.commit()
    finally:
        conn.close()
    return jsonify({"ok": True, "goal_id": goal_id, "silenced": True})


@api_bp.route("/goals/<int:goal_id>/resume", methods=["POST"])
@require_api_key
def resume_goal(goal_id):
    conn = get_db_connection()
    try:
        row = conn.execute(
            "SELECT iteration FROM goals WHERE id = ?", (goal_id,)
        ).fetchone()
        if not row:
            return jsonify({"error": "Goal not found"}), 404
        conn.execute("UPDATE goals SET is_silenced = 0 WHERE id = ?", (goal_id,))
        conn.commit()
        iteration = row["iteration"]
    finally:
        conn.close()
    if iteration:
        schedule_reminder(goal_id, iteration)
    return jsonify({"ok": True, "goal_id": goal_id, "silenced": False})


@api_bp.route("/settings", methods=["GET"])
@require_api_key
def get_settings():
    slot = get_iteration_slot()
    return jsonify(
        {
            "iteration_slot": {
                **slot,
                "weekday_name": WEEKDAY_NAMES[slot["weekday"]],
            },
            "default_email": get_setting("default_email"),
        }
    )


@api_bp.route("/settings", methods=["PATCH"])
@require_api_key
def update_settings():
    data = request.get_json(silent=True) or {}
    changed_slot = False
    slot_update = data.get("iteration_slot") or {}
    if slot_update:
        wd = slot_update.get("weekday")
        hr = slot_update.get("hour")
        mn = slot_update.get("minute")
        if wd is not None and not (0 <= int(wd) <= 6):
            return jsonify({"error": "weekday must be 0..6 (0=Monday)"}), 400
        if hr is not None and not (0 <= int(hr) <= 23):
            return jsonify({"error": "hour must be 0..23"}), 400
        if mn is not None and not (0 <= int(mn) <= 59):
            return jsonify({"error": "minute must be 0..59"}), 400
        set_iteration_slot(weekday=wd, hour=hr, minute=mn)
        changed_slot = True

    if "default_email" in data and data["default_email"]:
        set_setting("default_email", data["default_email"])
        import os as _os
        _os.environ["DEFAULT_TO_ADDRESS"] = data["default_email"]

    rescheduled = []
    if changed_slot:
        rescheduled = reschedule_all_active()

    slot = get_iteration_slot()
    return jsonify(
        {
            "iteration_slot": {**slot, "weekday_name": WEEKDAY_NAMES[slot["weekday"]]},
            "rescheduled_goals": [{"goal_id": gid, "next_run": nxt} for gid, nxt in rescheduled],
        }
    )


@api_bp.route("/goals/<int:goal_id>/history", methods=["GET"])
@require_api_key
def goal_history(goal_id):
    conn = get_db_connection()
    try:
        goal_rows = conn.execute(
            """
            SELECT completed, was_done, next_steps, reward, timestamp
            FROM goal_history WHERE goal_id = ? ORDER BY timestamp DESC
            """,
            (goal_id,),
        ).fetchall()
        iter_rows = conn.execute(
            """
            SELECT status, next_run, updated_at FROM iteration_history
            WHERE iteration_id = ? ORDER BY updated_at DESC
            """,
            (goal_id,),
        ).fetchall()
    finally:
        conn.close()
    return jsonify(
        {
            "goal_history": [dict(r) for r in goal_rows],
            "iteration_history": [dict(r) for r in iter_rows],
        }
    )