#!/bin/bash
# ╔══════════════════════════════════════════════════════════════════╗
# ║  arch-dev :: entrypoint                                         ║
# ║  Seeds /home/dev from skel template on first run.               ║
# ║  Updates dotfiles when image is newer than home.                ║
# ║  Initializes git for snapshot/rollback functionality.           ║
# ╚══════════════════════════════════════════════════════════════════╝

set -e

SKEL=/etc/skel-arch-dev
HOME_DIR=/home/dev
MARKER="$HOME_DIR/.arch-dev-initialized"
GITDIR="$HOME_DIR/.arch-dev-state"

# ── First run: seed everything from skel ──────────────────────────────────────
if [[ ! -f "$MARKER" ]]; then
    echo "🌱 arch-dev: first run — seeding home from skeleton..."
    # Copy everything except things that should not exist yet
    rsync -a --chown=dev:dev "$SKEL/" "$HOME_DIR/"

    # Initialize git repo for snapshots
    cd "$HOME_DIR"
    git init --quiet --separate-git-dir="$GITDIR" .
    git --git-dir="$GITDIR" --work-tree="$HOME_DIR" config user.name "arch-dev"
    git --git-dir="$GITDIR" --work-tree="$HOME_DIR" config user.email "dev@arch-dev.local"

    # Write .gitignore to exclude noise
    cat > "$HOME_DIR/.gitignore" <<'GITIGNORE'
# Caches and logs
.cache/
.local/state/
.local/share/nvim/log
.local/share/nvim/lazy-lock.json.bak
.npm/
__pycache__/
*.pyc

# History (intentional — too noisy to track)
.zsh_history
.lesshst
.bash_history
.python_history

# Compiled neovim plugin caches
.local/share/nvim/lazy/*/plugin/packer_compiled.lua

# Trash
.local/share/Trash/
GITIGNORE

    git --git-dir="$GITDIR" --work-tree="$HOME_DIR" add -A
    git --git-dir="$GITDIR" --work-tree="$HOME_DIR" commit -q -m "initial: arch-dev skeleton baked"
    git --git-dir="$GITDIR" --work-tree="$HOME_DIR" tag -a "skeleton" -m "factory state"

    touch "$MARKER"
    echo "✓ arch-dev: home initialized with snapshot 'skeleton'"

# ── Subsequent runs: refresh dotfiles only if image is newer ──────────────────
else
    SKEL_TIME=$(stat -c %Y "$SKEL/.zshrc" 2>/dev/null || echo 0)
    HOME_TIME=$(stat -c %Y "$HOME_DIR/.zshrc" 2>/dev/null || echo 0)

    if [[ "$SKEL_TIME" -gt "$HOME_TIME" ]]; then
        echo "🔄 arch-dev: image dotfiles newer than home — updating..."
        # Auto-snapshot before updating, in case user wants to revert
        if [[ -d "$GITDIR" ]]; then
            git --git-dir="$GITDIR" --work-tree="$HOME_DIR" add -A 2>/dev/null
            git --git-dir="$GITDIR" --work-tree="$HOME_DIR" \
                commit -q -m "auto: pre-update snapshot $(date +%Y%m%d-%H%M%S)" 2>/dev/null || true
        fi
        # Refresh only the dotfiles, not user data
        rsync -a --chown=dev:dev \
            --exclude='.local/share/nvim/lazy' \
            --exclude='.cache' \
            "$SKEL/" "$HOME_DIR/"
        echo "✓ arch-dev: dotfiles updated (auto-snapshot taken first)"
    fi
fi

# ── Hand off ──────────────────────────────────────────────────────────────────
cd "$HOME_DIR"
exec "$@"