#!/bin/bash
# validator/lib/-skill--execute.sh — validate a skill directory against the agentskills.io spec

_validator__skill__execute() {
  local FUNCTION_NAME="_validator__skill__execute"
  local SKILL_DIR=""

  # ── Parse args ──────────────────────────────────────────────────────────────
  while [[ $# -gt 0 ]]; do
    case "$1" in
      --skill-dir=*) SKILL_DIR="${1#*=}"; shift ;;
      --skill-dir)   SKILL_DIR="$2"; shift 2 ;;
      --help|-h)
        cat <<EOF
Usage: task -t scripts/Taskfile.yml validate-shell -- --skill-dir="<path>"

Validate an Agent Skill directory against the agentskills.io specification.

Options:
  --skill-dir PATH    Path to the skill directory to validate (required)

Checks:
  - SKILL.md exists
  - YAML frontmatter is present (--- delimiters)
  - 'name' field is present and valid (a-z, 0-9, hyphens only)
  - 'name' matches the directory name
  - 'name' is <= 64 characters, no leading/trailing/consecutive hyphens
  - 'description' field is present and <= 1024 characters
  - SKILL.md body is <= 500 lines (warning if exceeded)
  - Optional directories: scripts/, references/, assets/

Exit codes:
  0  All checks passed
  1  One or more checks failed
  2  Usage error

Examples:
  task -t scripts/Taskfile.yml validate-shell -- --skill-dir=".agents/skills/my-skill"
EOF
        return 0
        ;;
      *) echo "Error: unknown argument: $1" >&2; return 2 ;;
    esac
  done

  # ── Validate required args ──────────────────────────────────────────────────
  if [[ -z "$SKILL_DIR" ]]; then
    echo "Error: --skill-dir is required." >&2
    echo "Usage: task -t scripts/Taskfile.yml validate-shell -- --skill-dir=\"<path>\"" >&2
    return 2
  fi

  SKILL_DIR="${SKILL_DIR%/}"  # strip trailing slash

  # ── Counters ────────────────────────────────────────────────────────────────
  local PASS=0 FAIL=0 WARN=0

  _pass() { echo "  ✅  $1"; ((PASS++)) || true; }
  _fail() { echo "  ❌  $1"; ((FAIL++)) || true; }
  _warn() { echo "  ⚠️   $1"; ((WARN++)) || true; }
  _info() { echo "  ℹ️   $1"; }

  echo ""
  echo "Validating skill: $SKILL_DIR"
  echo "──────────────────────────────────────────"

  # ── Check: directory exists ─────────────────────────────────────────────────
  if [[ ! -d "$SKILL_DIR" ]]; then
    echo "Error: directory not found: $SKILL_DIR" >&2
    return 2
  fi

  local SKILL_FILE="$SKILL_DIR/SKILL.md"
  local DIR_NAME
  DIR_NAME="$(basename "$SKILL_DIR")"

  # ── Check: SKILL.md exists ──────────────────────────────────────────────────
  if [[ ! -f "$SKILL_FILE" ]]; then
    _fail "SKILL.md not found in $SKILL_DIR"
    echo ""; echo "Result: ❌ FAILED"; return 1
  fi
  _pass "SKILL.md exists"

  # ── Check: frontmatter delimiters ───────────────────────────────────────────
  local CONTENT
  CONTENT="$(cat "$SKILL_FILE")"
  if ! echo "$CONTENT" | grep -q "^---$"; then
    _fail "SKILL.md is missing YAML frontmatter (--- delimiters)"
    echo ""; echo "Result: ❌ FAILED"; return 1
  fi
  _pass "YAML frontmatter delimiters found"

  # ── Extract frontmatter ─────────────────────────────────────────────────────
  local FRONTMATTER
  FRONTMATTER="$(awk '/^---$/{if(p==0){p=1;next}else{exit}} p{print}' "$SKILL_FILE")"

  # ── Check: name field ───────────────────────────────────────────────────────
  local NAME_RAW NAME
  NAME_RAW="$(echo "$FRONTMATTER" | grep "^name:" | head -1 | sed 's/^name:[[:space:]]*//')"
  NAME="$(echo "$NAME_RAW" | tr -d "'\"" | tr -d '[:space:]')"

  if [[ -z "$NAME" ]]; then
    _fail "'name' field is missing or empty"
  else
    _pass "'name' field is present: $NAME"

    if [[ "$NAME" != "$DIR_NAME" ]]; then
      _fail "'name' ($NAME) does not match directory name ($DIR_NAME)"
    else
      _pass "'name' matches directory name"
    fi

    local NAME_LEN="${#NAME}"
    if [[ $NAME_LEN -gt 64 ]]; then
      _fail "'name' is $NAME_LEN characters (max 64)"
    else
      _pass "'name' length is $NAME_LEN (max 64)"
    fi

    if echo "$NAME" | grep -q '[^a-z0-9-]'; then
      _fail "'name' contains invalid characters (only a-z, 0-9, - allowed)"
    else
      _pass "'name' uses only allowed characters (a-z, 0-9, -)"
    fi

    if [[ "$NAME" == -* ]]; then
      _fail "'name' must not start with a hyphen"
    else
      _pass "'name' does not start with a hyphen"
    fi

    if [[ "$NAME" == *- ]]; then
      _fail "'name' must not end with a hyphen"
    else
      _pass "'name' does not end with a hyphen"
    fi

    if echo "$NAME" | grep -q "\-\-"; then
      _fail "'name' must not contain consecutive hyphens (--)"
    else
      _pass "'name' has no consecutive hyphens"
    fi
  fi

  # ── Check: description field ────────────────────────────────────────────────
  local DESC_LINE
  DESC_LINE="$(echo "$FRONTMATTER" | grep "^description:" | head -1)"

  if [[ -z "$DESC_LINE" ]]; then
    _fail "'description' field is missing"
  else
    local DESC_VALUE
    DESC_VALUE="$(echo "$DESC_LINE" | sed 's/^description:[[:space:]]*//')"
    local DESC_FULL

    if [[ "$DESC_VALUE" == ">" || "$DESC_VALUE" == "|" || -z "$DESC_VALUE" ]]; then
      local DESC_BODY
      DESC_BODY="$(awk '/^description:/{found=1; next} found && /^  /{print; next} found && /^[^ ]/{exit}' "$SKILL_FILE" | sed 's/^  //')"
      DESC_FULL="$(echo "$DESC_BODY" | tr '\n' ' ' | sed 's/[[:space:]]*$//')"
    else
      DESC_FULL="$DESC_VALUE"
    fi

    if [[ -z "$DESC_FULL" ]]; then
      _fail "'description' is empty"
    else
      local DESC_LEN="${#DESC_FULL}"
      _pass "'description' is present (${DESC_LEN} chars)"
      if [[ $DESC_LEN -gt 1024 ]]; then
        _fail "'description' is $DESC_LEN characters (max 1024)"
      else
        _pass "'description' length is $DESC_LEN (max 1024)"
      fi
    fi
  fi

  # ── Check: body length ──────────────────────────────────────────────────────
  local BODY_LINES
  BODY_LINES="$(awk '/^---$/{n++} n>=2{print}' "$SKILL_FILE" | wc -l | tr -d ' ')"
  if [[ $BODY_LINES -gt 500 ]]; then
    _warn "SKILL.md body is $BODY_LINES lines (recommended max 500). Consider moving detail to references/."
  else
    _pass "SKILL.md body is $BODY_LINES lines (max 500 recommended)"
  fi

  # ── Optional directories ────────────────────────────────────────────────────
  echo ""
  _info "Optional directories:"
  for dir in scripts references assets; do
    if [[ -d "$SKILL_DIR/$dir" ]]; then
      local FILE_COUNT
      FILE_COUNT="$(find "$SKILL_DIR/$dir" -type f | wc -l | tr -d ' ')"
      _info "  $dir/ — found ($FILE_COUNT files)"
    else
      _info "  $dir/ — not present"
    fi
  done

  # ── Summary ─────────────────────────────────────────────────────────────────
  echo ""
  echo "──────────────────────────────────────────"
  echo "Passed: $PASS  |  Failed: $FAIL  |  Warnings: $WARN"
  echo ""

  if [[ $FAIL -gt 0 ]]; then
    echo "Result: ❌ FAILED"; return 1
  elif [[ $WARN -gt 0 ]]; then
    echo "Result: ✅ PASSED (with warnings)"; return 0
  else
    echo "Result: ✅ PASSED"; return 0
  fi
}