#!/bin/bash
# Copyright (C) 2026 Cédric Abonnel
# License: GNU Affero General Public License v3

set -euo pipefail

# --- Configuration ---
BASE_DIR="/opt/monitoring"
CONF_DIR="${BASE_DIR}/conf"
LOG_DIR="/var/log/monitoring"
STATE_DIR="/var/lib/monitoring"
LOCK_DIR="/var/lock/monitoring"
TMP_DIR="/tmp/monitoring-install"

UPDATE_BASE_URL="https://git.abonnel.fr/cedricAbonnel/scripts-bash/raw/branch/main/servers/linux/monitoring"
MANIFEST_URL="${UPDATE_BASE_URL}/manifest.txt"

INSTALL_DEPS="${INSTALL_DEPS:-true}"

# --- Fonctions d'affichage ---
info() { echo -e "\e[34m[INFO]\e[0m $1"; }
ok() { echo -e "\e[32m[OK]\e[0m $1"; }
warn() { echo -e "\e[33m[WARN]\e[0m $1"; }
err() { echo -e "\e[31m[ERR]\e[0m $1"; }

# --- Fonctions Techniques ---

require_root() {
    if [ "${EUID}" -ne 0 ]; then
        err "Ce script doit être exécuté en root."
        exit 1
    fi
}

install_deps() {
    if [ "${INSTALL_DEPS}" != "true" ]; then return 0; fi
    info "Vérification des dépendances système..."
    if command -v apt-get >/dev/null 2>&1; then
        apt-get update -qq
        apt-get install -y -qq curl coreutils findutils grep sed gawk util-linux ca-certificates php-cli php-curl php-common > /dev/null
        ok "Dépendances installées."
    fi
}

prepare_dirs() {
    info "Préparation de l'arborescence dans ${BASE_DIR}..."
    mkdir -p "${BASE_DIR}/bin" "${BASE_DIR}/lib" "${CONF_DIR}" "${LOG_DIR}" "${STATE_DIR}" "${LOCK_DIR}" "${TMP_DIR}"
}

fetch_manifest() {
    info "Téléchargement du manifeste distant..."
    curl -fsS "${MANIFEST_URL}" -o "${TMP_DIR}/manifest.txt"
}

validate_manifest() {
    awk '
        NF == 3 &&
        $1 ~ /^[0-9a-fA-F]{64}$/ &&
        $2 ~ /^(644|755|600)$/ &&
        $3 ~ /^(bin|lib|conf)\/[A-Za-z0-9._\/-]+$/ &&
        $3 !~ /\.\./
    ' "${TMP_DIR}/manifest.txt"
}

download_and_install() {
    local expected_hash="$1"
    local mode="$2"
    local rel_path="$3"
    local dst="${BASE_DIR}/${rel_path}"

    if [ -f "$dst" ]; then
        local current_hash
        current_hash=$(sha256sum "$dst" | awk '{print $1}')
        if [ "$current_hash" == "$expected_hash" ]; then
            return 0 # Déjà à jour
        fi
        info "Mise à jour : $rel_path"
    else
        info "Installation : $rel_path"
    fi

    local tmp_file
    tmp_file="$(mktemp "${TMP_DIR}/file.XXXXXX")"
    
    if ! curl -fsS "${UPDATE_BASE_URL}/${rel_path}" -o "$tmp_file"; then
        err "Échec du téléchargement pour $rel_path"
        rm -f "$tmp_file"
        return 1
    fi

    local got_hash
    got_hash=$(sha256sum "$tmp_file" | awk '{print $1}')
    if [ "$got_hash" != "$expected_hash" ]; then
        err "Hash invalide pour $rel_path"
        rm -f "$tmp_file"
        return 1
    fi

    mkdir -p "$(dirname "$dst")"
    mv -f "$tmp_file" "$dst"
    chmod "$mode" "$dst"
}

purge_obsolete_files() {
    info "Analyse des fichiers obsolètes (Synchronisation avec Git)..."
    # On scanne bin, lib et conf
    find "${BASE_DIR}/bin" "${BASE_DIR}/lib" "${BASE_DIR}/conf" -type f | while read -r local_file; do
        
        local rel_path="${local_file#$BASE_DIR/}"

        # PROTECTION : On ne touche jamais aux fichiers locaux personnels
        if [[ "$rel_path" == *".local."* ]]; then
            continue
        fi

        # Si le fichier n'est pas dans le manifeste validé, on le supprime
        if ! grep -qW "$rel_path" "${TMP_DIR}/manifest-valid.txt"; then
            warn "Suppression : $rel_path (absent du dépôt)"
            rm -f "$local_file"
        fi
    done
}

# --- Main ---

main() {
    require_root
    install_deps
    prepare_dirs
    fetch_manifest

    if ! validate_manifest > "${TMP_DIR}/manifest-valid.txt"; then
        err "Le manifeste est invalide ou corrompu."
        exit 1
    fi

    echo "--------------------------------------------------"
    info "Phase 1 : Installation et mises à jour"
    while read -r hash mode rel_path; do
        [ -n "${hash:-}" ] || continue
        download_and_install "$hash" "$mode" "$rel_path"
    done < "${TMP_DIR}/manifest-valid.txt"

    echo "--------------------------------------------------"
    info "Phase 2 : Nettoyage"
    purge_obsolete_files

    rm -rf "${TMP_DIR}"
    echo "--------------------------------------------------"
    ok "Opération terminée avec succès."
    
    # Rappel final
    if [ ! -f "${CONF_DIR}/monitoring.local.conf.php" ]; then
        warn "Pensez à créer votre fichier ${CONF_DIR}/monitoring.local.conf.php"
    fi
}

main "$@"