//! Email snooze and waiting-for-response state.
//!
//! The email analogue of `task_repo_state`'s six functions over `tasks`; the
//! shared shape is deliberate and left visible rather than consolidated.

use chrono::{DateTime, Utc};
use goingson_core::{Email, EmailId, Result, UserId};
use rusqlite::{Connection, params};

use crate::utils::{execute, format_datetime, format_datetime_now, format_datetime_opt, query_all};

use super::query;
use super::row::{EMAIL_SELECT_COLUMNS, EmailRow};

/// Snooze one email until the given time.
pub(super) fn snooze(
    conn: &Connection,
    id: EmailId,
    user_id: UserId,
    until: DateTime<Utc>,
) -> Result<Option<Email>> {
    let until_str = format_datetime(&until);
    let result = execute(
        conn,
        "UPDATE emails SET snoozed_until = ? WHERE id = ? AND user_id = ?",
        params![&until_str, id.to_string(), user_id.to_string()],
    )?;
    if result > 0 {
        query::get_by_id(conn, id, user_id)
    } else {
        Ok(None)
    }
}

/// Remove the snooze from one email.
pub(super) fn unsnooze(conn: &Connection, id: EmailId, user_id: UserId) -> Result<Option<Email>> {
    let result = execute(
        conn,
        "UPDATE emails SET snoozed_until = NULL WHERE id = ? AND user_id = ?",
        params![id.to_string(), user_id.to_string()],
    )?;
    if result > 0 {
        query::get_by_id(conn, id, user_id)
    } else {
        Ok(None)
    }
}

/// Emails still snoozed into the future, soonest first.
pub(super) fn list_snoozed(conn: &Connection, user_id: UserId) -> Result<Vec<Email>> {
    let query = format!(
        "SELECT {EMAIL_SELECT_COLUMNS} FROM emails e LEFT JOIN projects p ON e.project_id = p.id AND p.user_id = ? WHERE e.user_id = ? AND e.snoozed_until IS NOT NULL AND datetime(e.snoozed_until) > datetime('now') ORDER BY e.snoozed_until ASC"
    );
    let rows = query_all(
        conn,
        &query,
        params![user_id.to_string(), user_id.to_string()],
        EmailRow::from_row,
    )?;
    rows.into_iter().map(Email::try_from).collect()
}

/// Flag one email as awaiting a reply, optionally by a date.
pub(super) fn mark_waiting(
    conn: &Connection,
    id: EmailId,
    user_id: UserId,
    expected_response: Option<DateTime<Utc>>,
) -> Result<Option<Email>> {
    let now = format_datetime_now();
    let expected = format_datetime_opt(expected_response);

    let result = execute(
        conn,
        "UPDATE emails SET waiting_for_response = 1, waiting_since = ?, expected_response_date = ? WHERE id = ? AND user_id = ?",
        params![&now, &expected, id.to_string(), user_id.to_string()],
    )?;

    if result > 0 {
        query::get_by_id(conn, id, user_id)
    } else {
        Ok(None)
    }
}

/// Clear the waiting-for-response flag on one email.
pub(super) fn clear_waiting(
    conn: &Connection,
    id: EmailId,
    user_id: UserId,
) -> Result<Option<Email>> {
    let result = execute(
        conn,
        "UPDATE emails SET waiting_for_response = 0, waiting_since = NULL, expected_response_date = NULL WHERE id = ? AND user_id = ?",
        params![id.to_string(), user_id.to_string()],
    )?;

    if result > 0 {
        query::get_by_id(conn, id, user_id)
    } else {
        Ok(None)
    }
}

/// Emails awaiting a reply, soonest expected response first.
pub(super) fn list_waiting(conn: &Connection, user_id: UserId) -> Result<Vec<Email>> {
    let query = format!(
        "SELECT {EMAIL_SELECT_COLUMNS} FROM emails e LEFT JOIN projects p ON e.project_id = p.id AND p.user_id = ? WHERE e.user_id = ? AND e.waiting_for_response = 1 ORDER BY e.expected_response_date ASC"
    );
    let rows = query_all(
        conn,
        &query,
        params![user_id.to_string(), user_id.to_string()],
        EmailRow::from_row,
    )?;
    rows.into_iter().map(Email::try_from).collect()
}