#!/usr/bin/env bash
# Build as the invoking user; elevate only the versioned system installation.
set -euo pipefail

usage() {
    cat <<'EOF'
Usage: scripts/install.sh [options]

Build and install Ferese's compositor, shell, CLI, and login-screen session.
Run from any directory as your normal user. Existing user config is preserved.

  --release-id ID  Name the installed release (default: UTC timestamp + PID)
  --skip-build     Install existing target/release binaries
  --replace-portal-config  Back up and replace existing Ferese portal configuration
  --offline        Build using only cached Cargo dependencies
  --resize-metrics Build with resize-barrier measurements (reported on exit)
  --dry-run        Print commands without building or installing
  -h, --help       Show this help

The previous release remains available for rollback. Administrator
authentication is requested only after a successful build.
EOF
}

check_user_portal_override() {
    local override=$1 user_home=$2
    [[ -f $override ]] || return 0
    if ! cmp -s -- <(printf '%s\n' '[Service]' 'ExecStart=' \
        "ExecStart=$user_home/.local/libexec/ferese/xdg-desktop-portal-ferese") "$override"; then
        echo "Custom portal override takes precedence over the installation: $override" >&2
        echo 'Update its ExecStart to /usr/local/lib/ferese/current/xdg-desktop-portal-ferese before installing.' >&2
        return 1
    fi
}

backup_user_portal_override() {
    local override=$1 user_home=$2 release=$3
    [[ -f $override ]] || return 0
    check_user_portal_override "$override" "$user_home" || return 1
    local backup="$override.before-$release"
    [[ ! -e $backup ]] || { echo "Portal override backup already exists: $backup" >&2; return 1; }
    mv -- "$override" "$backup"
    echo "Backed up old development portal override: $backup"
}

fail() { echo "ferese installer: $*" >&2; exit 1; }
repo_dir=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)
release_id="$(date -u +%Y%m%d-%H%M%S)-$$"
skip_build=false
replace_portal_config=false
offline=false
resize_metrics=false
dry_run=false
while (($#)); do
    case $1 in
        --release-id)
            (($# >= 2)) || fail '--release-id requires a value'
            release_id=$2
            shift 2
            ;;
        --skip-build) skip_build=true; shift ;;
        --replace-portal-config) replace_portal_config=true; shift ;;
        --offline) offline=true; shift ;;
        --resize-metrics) resize_metrics=true; shift ;;
        --dry-run) dry_run=true; shift ;;
        -h|--help) usage; exit 0 ;;
        *) fail "unknown option: $1 (see --help)" ;;
    esac
done
[[ $release_id =~ ^[a-zA-Z0-9][a-zA-Z0-9._-]*$ ]] || fail 'invalid release ID'
if $skip_build && $resize_metrics; then
    fail '--resize-metrics requires a build; omit --skip-build'
fi

[[ $(uname -s) == Linux ]] || fail 'Ferese requires Linux'
for tool in desktop-file-validate dbus-run-session; do
    command -v "$tool" >/dev/null || fail "required command not found: $tool"
done
desktop-file-validate "$repo_dir/packaging/ferese.desktop"
user_portal_override="${XDG_CONFIG_HOME:-$HOME/.config}/systemd/user/xdg-desktop-portal-ferese.service.d/override.conf"
if ((EUID != 0)); then
    check_user_portal_override "$user_portal_override" "$HOME" || fail 'portal service override needs attention'
fi

build=(cargo build --manifest-path "$repo_dir/Cargo.toml"
    --target-dir "$repo_dir/target" --release --locked
    -p ferese -p ferese-shell -p ferese-settings -p feresectl -p ferese-lock -p ferese-polkit-agent -p xdg-desktop-portal-ferese)
if $offline; then build+=(--offline); fi
if $resize_metrics; then build+=(--features ferese/resize-metrics); fi
if ! $skip_build; then
    ((EUID != 0)) || fail 'build as your normal user, without sudo (or use --skip-build)'
    command -v cargo >/dev/null || fail 'install the Rust toolchain and Cargo first'
fi

installer=(bash "$repo_dir/scripts/install-session.sh" "$release_id")
if $replace_portal_config; then installer+=(--replace-portal-config); fi
if ((EUID != 0)); then
    if command -v sudo >/dev/null; then
        installer=(sudo "${installer[@]}")
    elif command -v pkexec >/dev/null; then
        installer=(pkexec /usr/bin/bash "$repo_dir/scripts/install-session.sh" "$release_id")
    else
        fail 'system installation requires sudo or pkexec'
    fi
fi

if $dry_run; then
    if ! $skip_build; then printf 'Build: '; printf '%q ' "${build[@]}"; printf '\n'; fi
    printf 'Install: '; printf '%q ' "${installer[@]}"; printf '\n'
    exit 0
fi

cd -- "$repo_dir"
if ! $skip_build; then "${build[@]}"; fi
for name in ferese ferese-shell ferese-settings feresectl ferese-lock ferese-polkit-agent xdg-desktop-portal-ferese ferese-record; do
    [[ -x $repo_dir/target/release/$name ]] || fail "missing release binary: $name"
done
"${installer[@]}"
if ((EUID != 0)) && [[ -f $user_portal_override ]]; then
    backup_user_portal_override "$user_portal_override" "$HOME" "$release_id" || fail 'could not update portal override'
    systemctl --user daemon-reload || fail 'could not reload the user portal service configuration'
fi
echo 'Installation complete. Log out and select Ferese at your login screen, or run ferese-session from a local TTY.'