#!/bin/bash
set -euo pipefail

# ds_install.sh SERVICE
#
# Handles the full install lifecycle on the remote server in a single SSH session.
# Called after the local dropshell has rsynced new template + config to a staging folder.
#
# Remote directory layout:
#   services/SERVICE/config/        ← live service config
#   services/SERVICE/template/      ← live template scripts
#   services/SERVICE/_staging/config/    ← new config (rsynced by local)
#   services/SERVICE/_staging/template/  ← new template (rsynced by local)
#
# Flow:
#   1. Run install-pre.sh from STAGING (new code + new config) → validate
#   2. Run uninstall.sh from LIVE (old code + old config) → stop old service
#   3. Swap staging → live (atomic replacement)
#   4. Run install.sh from LIVE (now the new version)
#
# If any step fails, the script exits immediately (set -e).
# If install-pre.sh fails, the old service is untouched.

# -- Determine paths --
SCRIPT_PATH="$(readlink -f "${BASH_SOURCE[0]}")"
AGENT_PATH="$(dirname "${SCRIPT_PATH}")"
DROPSHELL_DIR="$(dirname "${AGENT_PATH}")"

# Export for scripts that need them
export AGENT_PATH
export DROPSHELL_DIR

# -- Source common functions --
source "${AGENT_PATH}/common.sh"

# -- Validate arguments --
if [[ $# -lt 1 ]]; then
    echo "Usage: ds_install.sh SERVICE [TEMP_DIR]" >&2
    exit 1
fi

SERVICE="$1"
export SERVICE
export TEMP_DIR="${2:-}"
export DOCKER_CLI_HINTS=false

SERVICE_DIR="${DROPSHELL_DIR}/services/${SERVICE}"
LIVE_CONFIG="${SERVICE_DIR}/config"
LIVE_TEMPLATE="${SERVICE_DIR}/template"
STAGING_DIR="${SERVICE_DIR}/_staging"
STAGING_CONFIG="${STAGING_DIR}/config"
STAGING_TEMPLATE="${STAGING_DIR}/template"

# -- Validate staging exists --
[[ -d "${STAGING_CONFIG}" ]] || _die "Staging config not found at ${STAGING_CONFIG}"
[[ -d "${STAGING_TEMPLATE}" ]] || _die "Staging template not found at ${STAGING_TEMPLATE}"
[[ -f "${DROPSHELL_DIR}/server_info.env" ]] || _die "Missing server_info.env"

# -- Helper: source env for a given template/config pair --
load_env() {
    local template_dir="$1"
    local config_dir="$2"

    # Find template_info.env
    local tinfo="${template_dir}/template_info.env"
    if [[ ! -f "${tinfo}" ]]; then
        tinfo="${template_dir}/config/.template_info.env"
    fi
    [[ -f "${tinfo}" ]] || _die "Missing template_info.env in ${template_dir}"

    # Must have service.env
    [[ -f "${config_dir}/service.env" ]] || _die "Missing service.env in ${config_dir}"

    # Source in order: server_info → template_info → service.env
    set -a
    source "${DROPSHELL_DIR}/server_info.env"
    source "${tinfo}"
    source "${config_dir}/service.env"
    set +a

    export CONFIG_PATH="${config_dir}"
    export TEMPLATE_PATH="${template_dir}"
}

# ═══════════════════════════════════════════════════════════════════
# STEP 1: Run install-pre.sh from STAGING (new code + new config)
# ═══════════════════════════════════════════════════════════════════
if [[ -f "${STAGING_TEMPLATE}/install-pre.sh" ]]; then
    echo "── Step 1: Running install-pre.sh (new version) ──"
    load_env "${STAGING_TEMPLATE}" "${STAGING_CONFIG}"
    cd "${STAGING_TEMPLATE}"

    if ! bash ./install-pre.sh; then
        echo "install-pre.sh failed — aborting install. Old service is untouched."
        rm -rf "${STAGING_DIR}"
        exit 1
    fi
else
    echo "── Step 1: No install-pre.sh — skipping ──"
fi

# ═══════════════════════════════════════════════════════════════════
# STEP 2: Run uninstall.sh from LIVE (old code + old config)
# ═══════════════════════════════════════════════════════════════════
if [[ -d "${LIVE_TEMPLATE}" ]] && [[ -f "${LIVE_TEMPLATE}/uninstall.sh" ]]; then
    echo "── Step 2: Running uninstall.sh (old version) ──"
    load_env "${LIVE_TEMPLATE}" "${LIVE_CONFIG}"
    cd "${LIVE_TEMPLATE}"

    # Uninstall is best-effort — don't abort if it fails
    bash ./uninstall.sh || echo "Warning: uninstall.sh failed, continuing anyway"
else
    echo "── Step 2: No existing service to uninstall ──"
fi

# ═══════════════════════════════════════════════════════════════════
# STEP 3: Swap staging → live
# ═══════════════════════════════════════════════════════════════════
echo "── Step 3: Swapping staging to live ──"

# Remove old live (if exists)
rm -rf "${LIVE_TEMPLATE}" "${LIVE_CONFIG}"

# Move staging into place
mkdir -p "${SERVICE_DIR}"
mv "${STAGING_CONFIG}" "${LIVE_CONFIG}"
mv "${STAGING_TEMPLATE}" "${LIVE_TEMPLATE}"
rm -rf "${STAGING_DIR}"

# ═══════════════════════════════════════════════════════════════════
# STEP 4: Run install.sh from LIVE (now the new version)
# ═══════════════════════════════════════════════════════════════════
echo "── Step 4: Running install.sh (new version) ──"
load_env "${LIVE_TEMPLATE}" "${LIVE_CONFIG}"
cd "${LIVE_TEMPLATE}"

bash ./install.sh || _die "install.sh failed"

echo "── Install complete for ${SERVICE} ──"