#!/usr/bin/env bash

# Agent skills, shipped to every machine.
#
# Panama is a desktop that an agent is frequently asked to operate: open the
# settings, check what is running, take a screenshot, run something as root. An
# agent that has to infer all of that from the source reliably invents half of
# it, so the machine carries its own manual and skills/ is where it lives.
#
# This stage is un-gated, unlike link-user. What it links is documentation of
# this repository, not anybody's personal content, so a stranger who clones
# Panama wants it for exactly the same reason its author does.
#
# ~/.agents/skills and ~/.claude/skills may each start as a single symlink into
# user/agents/skills, but a directory cannot point at personal and shipped
# skills at once. Both destinations become real directories with one link per
# skill. link-user runs after this stage on purpose, so a personal skill named
# like a shipped one wins in every agent runtime.

set -euo pipefail

log() { echo -e "\033[1;34m[INFO]\033[0m $*"; }

PANAMA_PATH="${PANAMA_PATH:-$HOME/.local/share/Panama}"
SKILLS_DIR="$PANAMA_PATH/skills"
PANAMA_OLD="$PANAMA_PATH/config/old"
DESTINATIONS=("$HOME/.agents/skills" "$HOME/.claude/skills")

[[ -d "$SKILLS_DIR" ]] || { log "No skills/ in this checkout; nothing to link."; exit 0; }

mkdir -p "$PANAMA_OLD"

# Moves whatever is already at a destination out of the way, once -- the same
# promise link-dotfiles and link-user make. A symlink is removed rather than
# backed up: it is a pointer this installer made, and keeping copies of it
# would grow config/old/ by one entry on every upgrade.
displace() {
    local destination="$1" backup
    if [[ -L "$destination" ]]; then
        rm -f "$destination"
        return 0
    fi
    [[ -e "$destination" ]] || return 0

    backup="$PANAMA_OLD/skills-$(printf '%s' "${destination#"$HOME"/}" | tr '/' '-')"
    if [[ -e "$backup" ]]; then
        backup="$backup.$(date +%s)"
    fi
    mv "$destination" "$backup"
    log "Moved existing $destination to $backup"
}

# Each destination has to be a real directory before anything can be linked
# into it. An old whole-directory symlink is removed; a regular file somebody
# left at the path is kept in config/old/.
for destination in "${DESTINATIONS[@]}"; do
    mkdir -p "$(dirname "$destination")"
    if [[ -L "$destination" ]]; then
        rm -f "$destination"
        log "Removed the old $destination symlink; skills are linked one by one now"
    elif [[ -e "$destination" && ! -d "$destination" ]]; then
        displace "$destination"
    fi
    mkdir -p "$destination"
done

linked=0
for skill in "$SKILLS_DIR"/*; do
    [[ -e "$skill" ]] || continue
    name="$(basename "$skill")"
    for destination in "${DESTINATIONS[@]}"; do
        target="$destination/$name"
        displace "$target"
        ln -s "$skill" "$target"
        log "Linked skills/$name → $target"
    done
    linked=$(( linked + 1 ))
done

log "Agent skills: $linked linked."