#!/usr/bin/env bash
set -euo pipefail

MOSAIC_HOME="${MOSAIC_HOME:-$HOME/.mosaic}"
FAIL_ON_WARN=0
VERBOSE=0

usage() {
  cat <<USAGE
Usage: $(basename "$0") [options]

Audit Mosaic runtime linkage and detect drift across agent runtimes.

Options:
  --fail-on-warn   Exit non-zero when warnings are found
  --verbose        Print pass checks too
  -h, --help       Show help
USAGE
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --fail-on-warn)
      FAIL_ON_WARN=1
      shift
      ;;
    --verbose)
      VERBOSE=1
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      echo "Unknown argument: $1" >&2
      usage >&2
      exit 1
      ;;
  esac
done

warn_count=0

warn() {
  warn_count=$((warn_count + 1))
  echo "[WARN] $*"
}

pass() {
  if [[ $VERBOSE -eq 1 ]]; then
    echo "[OK] $*"
  fi
}

expect_dir() {
  local d="$1"
  if [[ ! -d "$d" ]]; then
    warn "Missing directory: $d"
  else
    pass "Directory present: $d"
  fi
}

expect_file() {
  local f="$1"
  if [[ ! -f "$f" ]]; then
    warn "Missing file: $f"
  else
    pass "File present: $f"
  fi
}

check_tree_links() {
  local src_root="$1"
  local dst_root="$2"

  [[ -d "$src_root" ]] || return

  while IFS= read -r -d '' src; do
    local rel dst
    rel="${src#$src_root/}"
    dst="$dst_root/$rel"

    if [[ ! -L "$dst" ]]; then
      warn "Not symlinked: $dst (expected -> $src)"
      continue
    fi

    local dst_real src_real
    dst_real="$(readlink -f "$dst" 2>/dev/null || true)"
    src_real="$(readlink -f "$src" 2>/dev/null || true)"

    if [[ -z "$dst_real" || -z "$src_real" || "$dst_real" != "$src_real" ]]; then
      warn "Drifted link: $dst (expected -> $src)"
    else
      pass "Linked: $dst"
    fi
  done < <(find "$src_root" -type f -print0)
}

echo "[mosaic-doctor] Mosaic home: $MOSAIC_HOME"

# Canonical Mosaic checks
expect_file "$MOSAIC_HOME/STANDARDS.md"
expect_dir "$MOSAIC_HOME/guides"
expect_dir "$MOSAIC_HOME/rails"
expect_dir "$MOSAIC_HOME/profiles"
expect_dir "$MOSAIC_HOME/templates/agent"
expect_dir "$MOSAIC_HOME/skills"
expect_dir "$MOSAIC_HOME/skills-local"
expect_file "$MOSAIC_HOME/bin/mosaic-link-runtime-assets"
expect_file "$MOSAIC_HOME/bin/mosaic-sync-skills"

# Claude runtime checks
check_tree_links "$MOSAIC_HOME/guides" "$HOME/.claude/agent-guides"
check_tree_links "$MOSAIC_HOME/rails/git" "$HOME/.claude/scripts/git"
check_tree_links "$MOSAIC_HOME/rails/codex" "$HOME/.claude/scripts/codex"
check_tree_links "$MOSAIC_HOME/rails/bootstrap" "$HOME/.claude/scripts/bootstrap"
check_tree_links "$MOSAIC_HOME/rails/cicd" "$HOME/.claude/scripts/cicd"
check_tree_links "$MOSAIC_HOME/rails/portainer" "$HOME/.claude/scripts/portainer"
check_tree_links "$MOSAIC_HOME/templates/agent" "$HOME/.claude/templates"
check_tree_links "$MOSAIC_HOME/profiles/domains" "$HOME/.claude/presets/domains"
check_tree_links "$MOSAIC_HOME/profiles/tech-stacks" "$HOME/.claude/presets/tech-stacks"
check_tree_links "$MOSAIC_HOME/profiles/workflows" "$HOME/.claude/presets/workflows"
check_tree_links "$MOSAIC_HOME/runtime/claude/settings-overlays" "$HOME/.claude/presets"

for rf in CLAUDE.md settings.json hooks-config.json context7-integration.md; do
  src="$MOSAIC_HOME/runtime/claude/$rf"
  dst="$HOME/.claude/$rf"
  [[ -f "$src" ]] || continue
  if [[ ! -L "$dst" ]]; then
    warn "Not symlinked: $dst (expected -> $src)"
    continue
  fi
  dst_real="$(readlink -f "$dst" 2>/dev/null || true)"
  src_real="$(readlink -f "$src" 2>/dev/null || true)"
  if [[ -z "$dst_real" || -z "$src_real" || "$dst_real" != "$src_real" ]]; then
    warn "Drifted link: $dst (expected -> $src)"
  else
    pass "Linked: $dst"
  fi
done

# Skills runtime checks
for runtime_skills in "$HOME/.claude/skills" "$HOME/.codex/skills" "$HOME/.config/opencode/skills"; do
  [[ -d "$runtime_skills" ]] || continue

  while IFS= read -r -d '' skill; do
    name="$(basename "$skill")"
    [[ "$name" == .* ]] && continue
    target="$runtime_skills/$name"

    if [[ ! -e "$target" ]]; then
      warn "Missing skill link: $target"
      continue
    fi

    if [[ ! -L "$target" ]]; then
      # Runtime-specific local skills are allowed only for hidden/system entries.
      warn "Non-symlink skill entry: $target"
      continue
    fi

    target_real="$(readlink -f "$target" 2>/dev/null || true)"
    skill_real="$(readlink -f "$skill" 2>/dev/null || true)"
    if [[ -z "$target_real" || -z "$skill_real" || "$target_real" != "$skill_real" ]]; then
      warn "Drifted skill link: $target (expected -> $skill)"
    else
      pass "Linked skill: $target"
    fi
  done < <(find "$MOSAIC_HOME/skills" "$MOSAIC_HOME/skills-local" -mindepth 1 -maxdepth 1 -type d -print0)
done

link_roots=(
  "$HOME/.claude/agent-guides"
  "$HOME/.claude/scripts"
  "$HOME/.claude/templates"
  "$HOME/.claude/presets"
  "$HOME/.claude/skills"
  "$HOME/.codex/skills"
  "$HOME/.config/opencode/skills"
)

existing_link_roots=()
for d in "${link_roots[@]}"; do
  [[ -e "$d" ]] && existing_link_roots+=("$d")
done

broken_links=0
if [[ ${#existing_link_roots[@]} -gt 0 ]]; then
  broken_links=$(find "${existing_link_roots[@]}" -xtype l 2>/dev/null | wc -l | tr -d ' ')
fi
if [[ "$broken_links" != "0" ]]; then
  warn "Broken symlinks detected across runtimes: $broken_links"
fi

echo "[mosaic-doctor] warnings=$warn_count"
if [[ $FAIL_ON_WARN -eq 1 && $warn_count -gt 0 ]]; then
  exit 1
fi