#!/bin/bash

# Restore NexusOS from Gitea (enderofwings/NexusOS). Clones or pulls the repo,
# rebuilds the memory DB from its SQL dump, then rebuilds the regenerable env
# (venv, frontend deps) and desktop integration (theme, terminal, panel).
#
#   restore.sh                Pull latest + rebuild.
#   restore.sh -c | --claude  Dry-run: fetch + show what a restore WOULD apply. No changes.

NEXUS_ROOT="$HOME/nexus-core"
REPO="https://git.enderofwings.com/enderofwings/NexusOS.git"
mode="${1:-}"

DB="$NEXUS_ROOT/synapse/memory/memory.db"
DB_SQL="$NEXUS_ROOT/synapse/memory/memory.db.sql"

detect_requirements() {
    if command -v nvidia-smi &>/dev/null || lspci 2>/dev/null | grep -qi nvidia; then
        echo "requirements-nvidia.txt"
    else
        echo "requirements-amd.txt"
    fi
}

# Fresh machine: clone. Existing: work in place.
if [ ! -d "$NEXUS_ROOT/.git" ]; then
    echo "No local repo — cloning from Gitea..."
    git clone "$REPO" "$NEXUS_ROOT" || { echo "Clone failed."; exit 1; }
fi
cd "$NEXUS_ROOT" || { echo "No $NEXUS_ROOT"; exit 1; }

# Check mode: dry-run. Fetch and show what a real restore would pull, no changes.
if [ "$mode" = "-c" ] || [ "$mode" = "--claude" ] || [ "$mode" = "check" ]; then
    echo "Fetching to preview restore (no changes)..."
    git fetch origin
    echo ""
    echo "Commits a restore would apply:"
    git log --oneline ..origin/main 2>/dev/null || echo "(up to date)"
    echo ""
    git diff --stat ..origin/main 2>/dev/null
    echo ""
    echo "(dry-run only — nothing changed. Apply with: restore)"
    exit 0
fi

echo "Pulling latest from Gitea..."
git pull --ff-only origin main || { echo "Pull failed (diverged? stash/commit local changes)."; exit 1; }

# Rebuild the memory DB from its SQL dump — only if there's no live DB, so we
# never clobber a machine that has newer conversations than the backup.
if [ -f "$DB_SQL" ] && [ ! -f "$DB" ]; then
    echo ""
    echo "Rebuilding memory DB from dump..."
    sqlite3 "$DB" < "$DB_SQL" && echo "Memory DB restored." \
        || echo "Warning: memory DB rebuild failed."
elif [ -f "$DB" ]; then
    echo "Live memory DB present — left as-is (dump not applied). Delete it first to restore from backup."
fi

echo ""
echo "Rebuilding Python environment..."
if [ ! -x "$NEXUS_ROOT/Promethean/bin/pip" ]; then
    python3 -m venv "$NEXUS_ROOT/Promethean"
fi
req=$(detect_requirements)
if [ -f "$NEXUS_ROOT/$req" ]; then
    "$NEXUS_ROOT/Promethean/bin/pip" install --upgrade pip -q
    "$NEXUS_ROOT/Promethean/bin/pip" install -r "$NEXUS_ROOT/$req"
else
    echo "Warning: $req not found — skipping pip install."
fi

echo ""
echo "Rebuilding frontend dependencies..."
cd "$NEXUS_ROOT/interface/web" && npm install
cd "$NEXUS_ROOT"

echo ""
echo "Restoring NexusOS desktop theme..."
theme_installer="$NEXUS_ROOT/assets/themes/install-theme.sh"
if [ -x "$theme_installer" ]; then
    "$theme_installer"
elif [ -f "$theme_installer" ]; then
    bash "$theme_installer"
else
    echo "Warning: $theme_installer not found — skipping theme restore."
fi

echo ""
echo "Installing Promethean Terminal launcher..."
term_installer="$NEXUS_ROOT/bin/promethean/install.sh"
if [ -x "$term_installer" ]; then
    "$term_installer"
else
    echo "Warning: $term_installer not found — skipping."
fi

echo ""
echo "Installing panel applet..."
panel_installer="$NEXUS_ROOT/bin/panel/install.sh"
if [ -x "$panel_installer" ]; then
    "$panel_installer"
else
    echo "Warning: $panel_installer not found — skipping panel install."
fi

echo ""
echo "Restore complete. Nexus is ready to start."
echo "Note: Ollama models are not in the backup — pull them with \`ollama pull <model>\` as needed."