#!/bin/bash

# App Updater command handler — `libreportal updater <sub>`
# ---------------------------------------------------------------------------
# Dispatched automatically by cli_initialize.sh (category -> cliHandleUpdaterCommands).
# Subcommands (the features/updater WebUI buttons route to these as tasks):
#   check            refresh the version/CVE data (runs the WebUI generator)
#   apply <app>      update one app — DISASTER-RECOVERY FIRST: snapshot the app
#                    via the backup engine, then pull + recreate; on failure,
#                    roll back to the snapshot automatically
#   apply-all [a,b]  apply to a comma-list (or every update-available app)
#   rollback <app>   restore the app's most recent pre-update snapshot
#
# State-changing subcommands use the standard task-exec split: invoked normally
# they enqueue a task (so the WebUI + CLI share locking + the audit trail);
# the task processor re-invokes them with LIBREPORTAL_TASK_EXEC=1 to do the work.

cliHandleUpdaterCommands()
{
    local sub="$initial_command2"
    local app="$initial_command3"

    case "$sub" in
        ""|"check")
            # Quick + safe — just regenerates the read-only data files. Source
            # the generator explicitly if the lazy loader hasn't mapped it yet
            # (new file; the array regen self-heals it on deploy, this covers
            # the gap before that).
            if ! declare -F webuiUpdaterScan >/dev/null 2>&1; then
                source "$install_scripts_dir/webui/data/generators/updater/webui_updater_scan.sh" 2>/dev/null
            fi
            webuiUpdaterScan
            ;;

        "apply"|"now")
            if [[ -z "$app" ]]; then isError "Usage: libreportal updater apply <app>"; return 1; fi
            if [[ "$LIBREPORTAL_TASK_EXEC" == "1" ]]; then
                updaterApplyApp "$app"
            else
                cliTaskRun "libreportal updater apply $app" "updater_apply" "$app" ""
            fi
            ;;

        "apply-all")
            local list="$app"  # optional comma-list in $initial_command3
            if [[ "$LIBREPORTAL_TASK_EXEC" == "1" ]]; then
                updaterApplyAll "$list"
            else
                cliTaskRun "libreportal updater apply-all $list" "updater_apply_all" "updater" ""
            fi
            ;;

        "rollback")
            if [[ -z "$app" ]]; then isError "Usage: libreportal updater rollback <app>"; return 1; fi
            if [[ "$LIBREPORTAL_TASK_EXEC" == "1" ]]; then
                updaterRollbackApp "$app"
            else
                cliTaskRun "libreportal updater rollback $app" "updater_rollback" "$app" ""
            fi
            ;;

        *)
            cliShowUpdaterHelp
            ;;
    esac
}

# Update one app with disaster-recovery: snapshot -> pull -> recreate -> verify,
# auto-rolling-back on failure. Uses existing primitives (the backup CLI for the
# snapshot, docker compose for the image swap) so it shares their locking/logging.
updaterApplyApp()
{
    local app="$1"
    local app_dir="$containers_dir/$app"
    if [[ ! -d "$app_dir" ]]; then isError "App '$app' is not installed."; return 1; fi

    isHeader "Updating $app (a recovery snapshot is taken first)"

    # 1. DISASTER RECOVERY — snapshot before touching anything.
    isNotice "Snapshotting $app before update…"
    if ! libreportal backup app "$app" >/dev/null 2>&1; then
        isNotice "Pre-update snapshot did not complete cleanly — continuing is risky; aborting $app update."
        updaterRecordHistory "$app" "update" "" "" "aborted-no-snapshot"
        return 1
    fi

    # 2. Capture the current image so we can record from->to / roll back.
    local before; before="$(grep -m1 -E '^\s*image:' "$app_dir/docker-compose.yml" 2>/dev/null | sed -E 's/^\s*image:\s*//; s/["'"'"']//g')"

    # 3. Pull + recreate (uses the real, install-type-aware compose helpers).
    isNotice "Pulling new image(s) for $app…"
    if updaterComposePull "$app" && dockerComposeUp "$app" >/dev/null 2>&1; then
        local after; after="$(grep -m1 -E '^\s*image:' "$app_dir/docker-compose.yml" 2>/dev/null | sed -E 's/^\s*image:\s*//; s/["'"'"']//g')"
        updaterRecordHistory "$app" "update" "$before" "$after" "ok"
        isSuccessful "$app updated. Rollback point retained."
        webuiUpdaterScan >/dev/null 2>&1 || true
        return 0
    fi

    # 4. Failure -> automatic rollback.
    isNotice "Update of $app failed — rolling back to the pre-update snapshot…"
    updaterRollbackApp "$app" "auto"
    updaterRecordHistory "$app" "update" "$before" "" "rolled-back"
    return 1
}

updaterApplyAll()
{
    local list="$1" failures=0
    if [[ -z "$list" ]]; then
        isNotice "No app list given; nothing to do (the WebUI passes the update-available apps)."
        return 0
    fi
    local IFS=','
    for app in $list; do
        [[ -z "$app" ]] && continue
        updaterApplyApp "$app" || failures=$((failures+1))
    done
    [[ $failures -gt 0 ]] && isNotice "$failures app(s) failed and were rolled back." || isSuccessful "All requested apps updated."
}

# Roll an app back to its most recent snapshot. $2='auto' suppresses the header
# (called from the failure path of an apply).
updaterRollbackApp()
{
    local app="$1" mode="$2"
    [[ "$mode" != "auto" ]] && isHeader "Rolling $app back to its pre-update snapshot"
    # Delegate to the backup engine's restore (latest snapshot for this app).
    if libreportal backup app "$app" restore latest >/dev/null 2>&1; then
        dockerComposeUp "$app" >/dev/null 2>&1 || true
        [[ "$mode" != "auto" ]] && updaterRecordHistory "$app" "rollback" "" "" "rolled-back"
        isSuccessful "$app restored from its pre-update snapshot."
        return 0
    fi
    isError "Could not roll $app back automatically — restore manually from the Backups page."
    return 1
}

# Force a fresh image pull for an app (mirrors up_app.sh's install-type split).
# dockerComposeUp uses --quiet-pull which won't re-fetch a moved tag, so we pull
# explicitly first to actually pick up a new image.
updaterComposePull()
{
    local app="$1" dir="${containers_dir%/}/$1"
    [ -d "$dir" ] || return 1
    if [[ "$CFG_DOCKER_INSTALL_TYPE" == "rootless" ]]; then
        dockerCommandRunInstallUser "cd $dir && docker compose pull" >/dev/null 2>&1
    else
        ( cd "$dir" && docker compose pull >/dev/null 2>&1 )
    fi
}

# Append an entry to history.json (best-effort; needs jq, skips silently if absent).
updaterRecordHistory()
{
    local app="$1" action="$2" from="$3" to="$4" result="$5"
    local f="$containers_dir/libreportal/frontend/data/updater/generated/history.json"
    command -v jq >/dev/null 2>&1 || return 0
    [ -f "$f" ] || printf '{ "entries": [] }\n' | runFileWrite "$f"
    local ts; ts="$(date -Iseconds 2>/dev/null || date)"
    local tmp; tmp="$(mktemp)"
    if jq --arg ts "$ts" --arg app "$app" --arg action "$action" --arg from "$from" --arg to "$to" --arg result "$result" \
        '.entries = ([{ts:$ts, app:$app, action:$action, from:$from, to:$to, result:$result}] + (.entries // []))[0:200]' \
        "$f" > "$tmp" 2>/dev/null; then
        runFileWrite "$f" < "$tmp"
    fi
    rm -f "$tmp"
}