<?php
/**
 * Buddy state — persistence for the pet's stats and identity.
 *
 * Storage: per-user, in `wp_usermeta` under key `buddy_state`. A single
 * JSON-shaped associative array. Picked user_meta over site-wide
 * options so multiple admins on the same site each get their own pet,
 * matching the per-user mental model.
 *
 * Stats range 0–100. Higher = better. Decay happens via WP-cron later
 * (Phase C); for Phase A the stats just persist as last set.
 */

if ( ! defined( 'ABSPATH' ) ) { exit; }

const BUDDY_META_KEY = 'buddy_state';

/**
 * Default state for a freshly-adopted pet. Used the first time a user
 * visits a Buddy-rendering page.
 */
function buddy_default_state() {
    return array(
        'name'      => __( 'Buddy', 'buddy' ),
        'species'   => 'default',
        'hunger'    => 80,
        'happiness' => 80,
        'health'    => 90,
        'energy'    => 70,
        'born_at'   => time(),
        'last_tick' => time(),
    );
}

/**
 * Fetch the current user's Buddy state, falling back to defaults and
 * persisting them on first read so the pet has a "birthday" timestamp.
 *
 * @param int $user_id Optional. Defaults to current user.
 * @return array { name, species, hunger, happiness, health, energy, born_at, last_tick }
 */
function buddy_get_state( $user_id = 0 ) {
    $user_id = $user_id ? (int) $user_id : get_current_user_id();
    if ( ! $user_id ) { return buddy_default_state(); }

    $state = get_user_meta( $user_id, BUDDY_META_KEY, true );
    if ( ! is_array( $state ) || empty( $state ) ) {
        $state = buddy_default_state();
        update_user_meta( $user_id, BUDDY_META_KEY, $state );
    }

    // Merge against defaults so newly-added keys appear with sensible
    // values for users adopted under earlier versions.
    return array_merge( buddy_default_state(), $state );
}

/**
 * Persist a partial state update for the current user. Unknown keys
 * are silently dropped; values are clamped to valid ranges.
 *
 * @param array $patch Keys: name (str), species (str), hunger/happiness/health/energy (int 0–100).
 * @return array The full updated state.
 */
function buddy_update_state( array $patch, $user_id = 0 ) {
    $user_id = $user_id ? (int) $user_id : get_current_user_id();
    if ( ! $user_id ) { return buddy_default_state(); }

    $state = buddy_get_state( $user_id );

    $stat_keys = array( 'hunger', 'happiness', 'health', 'energy' );
    foreach ( $stat_keys as $k ) {
        if ( array_key_exists( $k, $patch ) ) {
            $state[ $k ] = max( 0, min( 100, (int) $patch[ $k ] ) );
        }
    }
    if ( array_key_exists( 'name', $patch ) ) {
        $name = sanitize_text_field( (string) $patch['name'] );
        if ( $name !== '' && mb_strlen( $name ) <= 32 ) {
            $state['name'] = $name;
        }
    }
    if ( array_key_exists( 'species', $patch ) ) {
        $allowed_species = array( 'default' ); // Phase D will widen this.
        $sp = sanitize_key( (string) $patch['species'] );
        if ( in_array( $sp, $allowed_species, true ) ) {
            $state['species'] = $sp;
        }
    }

    update_user_meta( $user_id, BUDDY_META_KEY, $state );
    return $state;
}

/**
 * Average of the four stats — used as a single "mood" indicator for
 * the dashboard widget. Returns 0–100.
 */
function buddy_overall_mood( array $state ) {
    $sum = (int) $state['hunger'] + (int) $state['happiness'] + (int) $state['health'] + (int) $state['energy'];
    return (int) round( $sum / 4 );
}

/**
 * Pick a one-word emoji / status label based on overall mood. Pure
 * cosmetic, used in the dashboard widget header.
 */
function buddy_mood_label( $mood_score ) {
    if ( $mood_score >= 80 ) { return array( 'label' => __( 'Thriving', 'buddy' ),  'tone' => 'happy' ); }
    if ( $mood_score >= 60 ) { return array( 'label' => __( 'Content', 'buddy' ),   'tone' => 'happy' ); }
    if ( $mood_score >= 40 ) { return array( 'label' => __( 'Okay', 'buddy' ),      'tone' => 'neutral' ); }
    if ( $mood_score >= 20 ) { return array( 'label' => __( 'Hungry', 'buddy' ),    'tone' => 'sad' ); }
    return array( 'label' => __( 'Distressed', 'buddy' ), 'tone' => 'sad' );
}