update.sh

#!/bin/bash

set -euo pipefail

REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd -P)"
cd "$REPO_ROOT" || exit 1

TMP_DIR="$(mktemp -d "$REPO_ROOT/.update.sh.XXXXXX")"
STAGE_DIR="$TMP_DIR/stage"
BACKUP_DIR="$TMP_DIR/backup"
mkdir -p "$STAGE_DIR" "$BACKUP_DIR"

declare -a MANAGED_TARGETS=()
declare -a APPLIED_TARGETS=()
APPLY_IN_PROGRESS=0

track_target() {
    local relative_target="$1"
    local existing_target

    if [ "${#MANAGED_TARGETS[@]}" -gt 0 ]; then
        for existing_target in "${MANAGED_TARGETS[@]}"; do
            if [ "$existing_target" = "$relative_target" ]; then
                return 0
            fi
        done
    fi

    MANAGED_TARGETS+=("$relative_target")
}

stage_file() {
    local source="$1"
    local relative_target="$2"
    local staged_target="$STAGE_DIR/$relative_target"

    track_target "$relative_target"

    if [ ! -e "$source" ] && [ ! -h "$source" ]; then
        return 0
    fi

    mkdir -p "$(dirname "$staged_target")"
    cp -P -v "$source" "$staged_target"
}

stage_directory() {
    local source_dir="$1"
    local relative_target="$2"
    local staged_target="$STAGE_DIR/$relative_target"

    track_target "$relative_target"

    if [ ! -d "$source_dir" ]; then
        return 0
    fi

    mkdir -p "$staged_target"
    cp -v -R "$source_dir"/. "$staged_target"/
}

generate_fisher_manifest() {
    local staged_target="$STAGE_DIR/fisher/fisher install.list"
    local fish_plugins=""
    local plugin

    track_target "fisher/fisher install.list"
    mkdir -p "$(dirname "$staged_target")"
    : > "$staged_target"

    if ! fish_plugins="$(fish -c 'fisher list')"; then
        return 1
    fi

    if [ -z "$fish_plugins" ]; then
        return 0
    fi

    while IFS= read -r plugin; do
        if [ -z "$plugin" ] || [ "$plugin" = "jorgebucaran/fisher" ]; then
            continue
        fi

        printf '%s\n' "$plugin" >> "$staged_target"
    done <<< "$fish_plugins"
}

generate_brewfile() {
    local staged_target="$STAGE_DIR/packages/Brewfile"

    track_target "packages/Brewfile"
    mkdir -p "$(dirname "$staged_target")"
    if ! brew bundle dump --force --describe --file="$staged_target"; then
        return 1
    fi
    [ -f "$staged_target" ]
}

restore_backups() {
    local index
    local relative_target
    local target_path
    local backup_path
    local rollback_failed=0

    for ((index=${#APPLIED_TARGETS[@]} - 1; index>=0; index--)); do
        relative_target="${APPLIED_TARGETS[$index]}"
        target_path="$REPO_ROOT/$relative_target"
        backup_path="$BACKUP_DIR/$relative_target"

        if ! rm -rf "$target_path"; then
            printf 'Rollback failed: could not remove %s\n' "$target_path" >&2
            rollback_failed=1
            continue
        fi

        if [ -e "$backup_path" ] || [ -h "$backup_path" ]; then
            if ! mkdir -p "$(dirname "$target_path")"; then
                printf 'Rollback failed: could not recreate parent for %s\n' "$target_path" >&2
                rollback_failed=1
                continue
            fi

            if ! mv "$backup_path" "$target_path"; then
                printf 'Rollback failed: could not restore %s\n' "$relative_target" >&2
                rollback_failed=1
            fi
        fi
    done

    return "$rollback_failed"
}

apply_target() {
    local relative_target="$1"
    local target_path="$REPO_ROOT/$relative_target"
    local staged_target="$STAGE_DIR/$relative_target"
    local backup_path="$BACKUP_DIR/$relative_target"

    mkdir -p "$(dirname "$backup_path")"

    if [ -e "$target_path" ] || [ -h "$target_path" ]; then
        mv "$target_path" "$backup_path"
    fi

    APPLIED_TARGETS+=("$relative_target")

    if [ -e "$staged_target" ] || [ -h "$staged_target" ]; then
        mkdir -p "$(dirname "$target_path")"
        mv "$staged_target" "$target_path"
    fi
}

apply_staged_targets() {
    local relative_target

    APPLY_IN_PROGRESS=1

    for relative_target in "${MANAGED_TARGETS[@]}"; do
        apply_target "$relative_target"
    done

    APPLY_IN_PROGRESS=0
}

cleanup() {
    local exit_code="$1"

    trap - EXIT

    if [ "$exit_code" -ne 0 ] && [ "$APPLY_IN_PROGRESS" -eq 1 ]; then
        if ! restore_backups; then
            printf 'Rollback failed; repo may be partially updated\n' >&2
            printf 'Rollback artifacts kept at %s\n' "$TMP_DIR" >&2
            exit "$exit_code"
        fi
    fi

    rm -rf "$TMP_DIR"
    exit "$exit_code"
}

trap 'cleanup "$?"' EXIT

fish_dir="$HOME/.config/fish"
stage_file "$fish_dir/config.fish" "fish/config.fish"
stage_file "$fish_dir/functions/fish_prompt.fish" "fish/functions/fish_prompt.fish"
stage_file "$fish_dir/functions/fish_greeting.fish" "fish/functions/fish_greeting.fish"
stage_file "$fish_dir/functions/fish_prompt_loading_indicator.fish" "fish/functions/fish_prompt_loading_indicator.fish"
stage_file "$fish_dir/conf.d/abbr.fish" "fish/conf.d/abbr.fish"
stage_file "$fish_dir/conf.d/alias.fish" "fish/conf.d/alias.fish"

claude_dir="$HOME/.claude"
stage_file "$claude_dir/settings.json" "claude/settings.json"
stage_file "$claude_dir/CLAUDE.md" "claude/CLAUDE.md"
stage_directory "$claude_dir/agents" "claude/agents"
stage_directory "$claude_dir/commands" "claude/commands"
stage_file "$HOME/.claude.json" "claude/claude.json"

opencode_dir="$HOME/.config/opencode"
stage_file "$opencode_dir/opencode.json" "opencode/opencode.json"
stage_file "$opencode_dir/AGENTS.md" "opencode/AGENTS.md"
stage_file "$opencode_dir/dcp.jsonc" "opencode/dcp.jsonc"
stage_directory "$opencode_dir/prompts" "opencode/prompts"
# Keep the legacy repo-only agent directory pruned.
track_target "opencode/agent"

ghostty_dir="$HOME/.config/ghostty"
stage_file "$ghostty_dir/config" "ghostty/config"

generate_fisher_manifest

stage_file "$HOME/.gitconfig" "git/.gitconfig"
stage_file "$HOME/.gitignore_global" "git/.gitignore_global"
stage_file "$HOME/.ssh/config" "ssh/config"

gnupg_dir="$HOME/.gnupg"
stage_file "$gnupg_dir/gpg.conf" "gnupg/gpg.conf"
stage_file "$gnupg_dir/gpg-agent.conf" "gnupg/gpg-agent.conf"

generate_brewfile
echo "brew bundle dump complete"

stage_file "$HOME/.config/starship.toml" "starship/starship.toml"

apply_staged_targets

echo "Update script complete"