#!/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.
#
# ~/.claude/skills was a single symlink into user/agents/skills until now, and
# a directory cannot be two things at once. So the destination becomes a real
# directory and every skill -- shipped here, personal from user/ -- is linked
# into it one at a time. link-user runs after this stage on purpose: it links
# last, so a personal skill named like a shipped one wins, which is the
# precedence Claude Code itself uses.

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"
DESTINATION="$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"
}

# The destination itself 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 this path is kept, in config/old/.
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"

linked=0
for skill in "$SKILLS_DIR"/*; do
    [[ -e "$skill" ]] || continue
    name="$(basename "$skill")"
    target="$DESTINATION/$name"

    displace "$target"
    ln -s "$skill" "$target"
    log "Linked skills/$name → $target"
    linked=$(( linked + 1 ))
done

log "Agent skills: $linked linked."