#!/bin/bash

# Keeping CFG_<APP>_STORAGE's comment truthful.
#
# The value is a location NAME, because names survive a migrate to a host whose
# disks are laid out differently and paths do not. But a name alone is useless to
# someone reading the config file at 2am with no tooling, so the RESOLVED PATH
# rides in the field's comment:
#
#   CFG_NEXTCLOUD_STORAGE=bigdisk   # Storage Location - Currently at /mnt/bigdisk/apps/nextcloud [default:Primary|bigdisk:Big disk]
#
# Two rules keep that from becoming a liability:
#
#   1. It is a BREADCRUMB, never a source of truth. Nothing reads it to decide
#      anything — appDir resolves by discovery. A stale one is cosmetic.
#   2. It is written ONLY when it changes. The app .config is user-editable and
#      lives in the container-owned tree, so an unconditional rewrite on every
#      regen is both file churn and a runFileOp per app per pass. Compare first.

# Rebuild the "[default:Primary|<name>:<label>|…]" option list from the registry,
# so a dropdown reflects locations added since the app was installed.
_storageOptionList()
{
    local out="default:Primary ($(primaryRoot))"
    local id state path name_var name
    while IFS=$'\t' read -r id state path; do
        [[ -z "$id" ]] && continue
        name_var="CFG_STORAGE_LOC_${id}_NAME"
        name="${!name_var:-location-$id}"
        # An unavailable location stays selectable and says so, rather than
        # vanishing from the list and looking like it was deleted.
        if [[ "$state" == "ok" ]]; then
            out+="|${name}:${name} (${path})"
        else
            out+="|${name}:${name} (${path}) — not mounted"
        fi
    done < <(runStorage verify 2>/dev/null)
    printf '%s' "$out"
}

# Rewrite one app's CFG_<APP>_STORAGE comment. No-op when nothing changed.
storageSyncAppComment()
{
    local app="$1"
    [[ -n "$app" ]] || return 0

    local dir cfg key up
    up="${app^^}"
    key="CFG_${up}_STORAGE"
    dir=$(appDir "$app") || return 0          # unavailable: leave the file alone
    cfg="$dir/$app.config"
    [[ -f "$cfg" ]] || return 0

    local line
    line=$(runCfgOp grep -m1 -E "^${key}=" "$cfg" 2>/dev/null) || return 0
    [[ -n "$line" ]] || return 0

    # Preserve the value and the READONLY marker; regenerate the rest.
    local value="${line#*=}"
    value="${value%%#*}"
    value="${value//$'\r'/}"
    value="${value#"${value%%[![:space:]]*}"}"
    value="${value%"${value##*[![:space:]]}"}"
    value="${value%\"}"; value="${value#\"}"

    local readonly_marker=""
    [[ "$line" == *'**READONLY**'* ]] && readonly_marker=" **READONLY**"

    local desc
    if [[ -n "$readonly_marker" ]]; then
        desc="Storage Location - Fixed: other apps reference $app by path. Currently at $dir"
    else
        desc="Storage Location - Currently at $dir [$(_storageOptionList)]"
    fi

    local want="${key}=${value}   # ${desc}${readonly_marker}"
    [[ "$line" == "$want" ]] && return 0       # unchanged: no write, no churn

    local escaped_key="${key}"
    local tmp; tmp=$(mktemp) || return 1
    runCfgOp cat "$cfg" 2>/dev/null > "$tmp" || { rm -f "$tmp"; return 1; }
    awk -v k="^${escaped_key}=" -v repl="$want" '
        $0 ~ k && !done { print repl; done=1; next }
        { print }
    ' "$tmp" | runCfgOp tee "$cfg" >/dev/null
    rm -f "$tmp"
    return 0
}

# Sync every installed app. Called from the regen path; cheap because each app
# short-circuits unless its resolved path or the option list actually changed.
storageSyncAllAppComments()
{
    local app
    while IFS= read -r app; do
        [[ -z "$app" || "$app" == "libreportal" ]] && continue
        storageSyncAppComment "$app"
    done < <(storageApps)
    return 0
}