#!/usr/bin/env bash
# SessionStart hook for code-guide plugin
# Injects mandatory skill context at session start (like Superpowers pattern)

set -euo pipefail

# Determine plugin root directory
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
PLUGIN_ROOT="$(cd "${SCRIPT_DIR}/.." && pwd)"

SKILLS_DIR="${PLUGIN_ROOT}/skills"

# Build the context string by extracting descriptions from mandatory skill SKILL.md files
build_context() {
  local ctx=""

  ctx="${ctx}<EXTREMELY_IMPORTANT>\n"
  ctx="${ctx}You have the code-guide plugin loaded. The following MANDATORY skills apply to EVERY coding task — load them via the Skill tool whenever relevant:\n\n"

  # Read each mandatory skill's frontmatter
  local mandatory="engineering-principles clean-code clean-architecture testing error-handling security git-workflow api-design"

  for skill in $mandatory; do
    local file="${SKILLS_DIR}/${skill}/SKILL.md"
    if [ -f "$file" ]; then
      # Extract description line — strip "description:" prefix and optional quotes
      local desc
      desc=$(grep "^description:" "$file" | head -1 | cut -d: -f2- | tr -d '\n')
      desc="${desc#\"}"  # strip leading quote if present
      desc="${desc%\"}"  # strip trailing quote if present
      desc="$(echo "$desc" | awk '{$1=$1};1')"  # trim whitespace
      ctx="${ctx}• code-guide:${skill} — ${desc}\n"
    fi
  done

  ctx="${ctx}\n"

  # Add non-mandatory skills list (so Claude knows they exist)
  ctx="${ctx}Other available skills (non-mandatory — trigger when relevant):\n"
  ctx="${ctx}typescript, python, rust, go, react-frontend, nextjs, hono-backend, elysiajs, drizzle-database, docker, ci-cd, monitoring, logging-observability, performance, documentation, design-patterns, monorepo\n"

  ctx="${ctx}\n"
  ctx="${ctx}<EXTREMELY_IMPORTANT>Rules you MUST follow at all times:\n"
  ctx="${ctx}1. NEVER suppress lints/type errors — fix the code instead.\n"
  ctx="${ctx}2. NEVER assume — show evidence from codebase/docs for everything.\n"
  ctx="${ctx}3. ASK when ambiguous — don't silently pick one interpretation.\n"
  ctx="${ctx}4. Use the Workflow tool for complex multi-step tasks that need parallel execution or adversarial verification.\n"
  ctx="${ctx}5. Fix root causes, not symptoms — patch the shared function, not every caller.\n"
  ctx="${ctx}6. Tests come first — code without tests is legacy code.\n"
  ctx="${ctx}7. The simplest solution that works is the correct one (YAGNI/KISS).\n"
  ctx="${ctx}8. Leave every module cleaner than you found it (Boy Scout Rule).\n"

  ctx="${ctx}\n"
  ctx="${ctx}When you need the full content of any skill, use the Skill tool to load it.\n"
  ctx="${ctx}</EXTREMELY_IMPORTANT>"

  printf '%s' "$ctx"
}

# Escape string for JSON embedding
escape_for_json() {
  local s="$1"
  s="${s//\\/\\\\}"
  s="${s//\"/\\\"}"
  s="${s//$'\n'/\\n}"
  s="${s//$'\r'/\\r}"
  s="${s//$'\t'/\\t}"
  printf '%s' "$s"
}

context=$(build_context)
escaped_context=$(escape_for_json "$context")

# Output JSON for Claude Code (hookSpecificOutput.additionalContext format)
printf '{"hookSpecificOutput":{"hookEventName":"SessionStart","additionalContext":"%s"}}\n' "$escaped_context"

exit 0