#!/usr/bin/env bash
# ============================================================
# spec-coding-skills 安装/更新脚本
# 用法: bash <(curl -sL <raw-url>/install.sh) [codex|claude|both] [--force-overwrite]
#   或: bash install.sh [codex|claude|both|目标目录] [--force-overwrite]
# ============================================================
set -euo pipefail

REPO_URL="https://git.internal.intelligrow.cn/zhangfucai/spec-coding-skills.git"
DEFAULT_MODE="codex"

GREEN='\033[0;32m'; YELLOW='\033[1;33m'; CYAN='\033[0;36m'; NC='\033[0m'
log_info()  { echo -e "${GREEN}[INFO]${NC}  $1"; }
log_warn()  { echo -e "${YELLOW}[WARN]${NC}  $1"; }
log_title() { echo -e "${CYAN}$1${NC}"; }

MODE=""
TARGET=""
SKILLS_SRC=""
GUIDE_SRC=""
GUIDE_DST=""
REQUEST="${1:-$DEFAULT_MODE}"
TOTAL_NEW=0
TOTAL_UPDATED=0
TOTAL_SKIPPED=0
TOTAL_PRESERVED=0
INSTALLED_TARGETS=""
FORCE_OVERWRITE="${SPEC_SKILLS_FORCE_OVERWRITE:-0}"

if [ "$#" -gt 0 ]; then
  REQUEST="$DEFAULT_MODE"
  REQUEST_SET=0
  for arg in "$@"; do
    case "$arg" in
      --force|--force-overwrite)
        FORCE_OVERWRITE=1
        ;;
      *)
        if [ "$REQUEST_SET" -eq 0 ]; then
          REQUEST="$arg"
          REQUEST_SET=1
        else
          log_warn "未知参数: $arg"
          exit 1
        fi
        ;;
    esac
  done
fi

resolve_layout() {
  local input="$1"

  case "$input" in
    ""|codex)
      MODE="codex"
      TARGET=".codex/skills"
      SKILLS_SRC=".codex/skills"
      GUIDE_SRC="AGENTS.md.template"
      GUIDE_DST="AGENTS.md"
      ;;
    claude)
      MODE="claude"
      TARGET=".claude/skills"
      SKILLS_SRC=".claude/skills"
      GUIDE_SRC="CLAUDE.md.template"
      GUIDE_DST="CLAUDE.md"
      ;;
    both)
      log_warn "both 不是单一布局，请在主流程中单独处理"
      exit 1
      ;;
    *)
      TARGET="$input"
      case "$TARGET" in
        *".claude/skills"*)
          MODE="claude"
          SKILLS_SRC=".claude/skills"
          GUIDE_SRC="CLAUDE.md.template"
          GUIDE_DST="CLAUDE.md"
          ;;
        *)
          MODE="codex"
          SKILLS_SRC=".codex/skills"
          GUIDE_SRC="AGENTS.md.template"
          GUIDE_DST="AGENTS.md"
          ;;
      esac
      ;;
  esac
}

TMP_DIR=$(mktemp -d)
trap "rm -rf $TMP_DIR" EXIT

file_hash() {
  if command -v shasum >/dev/null 2>&1; then
    shasum -a 256 "$1" | awk '{print $1}'
  elif command -v sha256sum >/dev/null 2>&1; then
    sha256sum "$1" | awk '{print $1}'
  else
    log_warn "缺少 shasum 或 sha256sum，无法进行本地差异保护"
    exit 1
  fi
}

state_file_for() {
  local dst="$1"
  local rel_path

  rel_path="${dst#$TARGET/}"
  if [ "$rel_path" = "$dst" ]; then
    rel_path="$(basename "$dst")"
  fi

  printf '%s/.install-state/%s.sha256' "$TARGET" "$rel_path"
}

write_install_state() {
  local src="$1"
  local dst="$2"
  local state_file

  state_file="$(state_file_for "$dst")"
  mkdir -p "$(dirname "$state_file")"
  file_hash "$src" >"$state_file"
}

is_unmodified_since_last_install() {
  local dst="$1"
  local state_file
  local dst_hash
  local expected_hash

  state_file="$(state_file_for "$dst")"
  [ -f "$state_file" ] || return 1

  dst_hash="$(file_hash "$dst")"
  expected_hash="$(cat "$state_file")"
  [ "$dst_hash" = "$expected_hash" ]
}

sync_file() {
  local src="$1"
  local dst="$2"
  local create_msg="$3"
  local update_msg="$4"

  if [ ! -f "$dst" ]; then
    mkdir -p "$(dirname "$dst")"
    cp "$src" "$dst"
    write_install_state "$src" "$dst"
    log_info "$create_msg"
    TOTAL_NEW=$((TOTAL_NEW + 1))
  elif ! diff -q "$src" "$dst" >/dev/null 2>&1; then
    if [ "$FORCE_OVERWRITE" = "1" ] || is_unmodified_since_last_install "$dst"; then
      cp "$dst" "$dst.local.bak"
      cp "$src" "$dst"
      write_install_state "$src" "$dst"
      log_warn "$update_msg"
      TOTAL_UPDATED=$((TOTAL_UPDATED + 1))
    else
      cp "$src" "${dst}.upstream.new"
      log_warn "🛡️  保留本地差异: ${dst}；远端新版已写入 ${dst}.upstream.new"
      TOTAL_PRESERVED=$((TOTAL_PRESERVED + 1))
    fi
  else
    write_install_state "$src" "$dst"
    TOTAL_SKIPPED=$((TOTAL_SKIPPED + 1))
  fi
}

sync_guide_file() {
  local src="$1"
  local dst="$2"
  local create_msg="$3"
  local skip_msg="$4"

  if [ ! -f "$dst" ]; then
    mkdir -p "$(dirname "$dst")"
    cp "$src" "$dst"
    log_info "$create_msg"
    TOTAL_NEW=$((TOTAL_NEW + 1))
  else
    log_info "$skip_msg"
    TOTAL_SKIPPED=$((TOTAL_SKIPPED + 1))
  fi
}

install_layout() {
  local input="$1"
  local skill_dir
  local skill_name
  local src_file
  local rel_path
  local dst_dir
  local dst_file
  local tpl_file
  local tpl_name
  local dst
  local guide_src_path

  resolve_layout "$input"

  if [ ! -d "$TMP_DIR/$SKILLS_SRC" ]; then
    log_warn "上游仓库中不存在技能目录: $SKILLS_SRC"
    exit 1
  fi

  log_info "同步 $MODE: $TARGET"
  mkdir -p "$TARGET"

  for skill_dir in "$TMP_DIR/$SKILLS_SRC"/*/; do
    [ -d "$skill_dir" ] || continue
    skill_name=$(basename "$skill_dir")
    dst_dir="$TARGET/$skill_name"

    [ -f "$skill_dir/SKILL.md" ] || continue

    while IFS= read -r -d '' src_file; do
      rel_path="${src_file#$skill_dir}"
      dst_file="$dst_dir/$rel_path"

      sync_file \
        "$src_file" \
        "$dst_file" \
        "✨ 新增: $skill_name/$rel_path ($MODE)" \
        "🔄 更新: $skill_name/$rel_path ($MODE) （本地版本已备份为 $(basename "$rel_path").local.bak）"
    done < <(find "$skill_dir" -type f -print0)
  done

  for tpl_file in "$TMP_DIR/$SKILLS_SRC"/*.template "$TMP_DIR/$SKILLS_SRC"/*.md; do
    [ -f "$tpl_file" ] || continue
    tpl_name=$(basename "$tpl_file")
    dst="$TARGET/$tpl_name"

    sync_file \
      "$tpl_file" \
      "$dst" \
      "✨ 新增模板: $tpl_name ($MODE)" \
      "🔄 更新模板: $tpl_name ($MODE) （本地版本已备份为 ${tpl_name}.local.bak）"
  done

  guide_src_path="$TMP_DIR/$GUIDE_SRC"
  if [ -f "$guide_src_path" ]; then
    sync_guide_file \
      "$guide_src_path" \
      "$GUIDE_DST" \
      "✨ 新增项目引导: ${GUIDE_DST}" \
      "⏭️  跳过项目引导: ${GUIDE_DST}（已存在，保持原样）"
  fi

  INSTALLED_TARGETS="${INSTALLED_TARGETS}${INSTALLED_TARGETS:+, }$TARGET"
}

# ---------- 拉取最新 ----------
log_title "📦 spec-coding-skills 安装/更新"
echo ""
log_info "拉取最新版本..."
git clone --depth 1 --quiet "$REPO_URL" "$TMP_DIR"

VERSION=$(git -C "$TMP_DIR" describe --tags --always 2>/dev/null || git -C "$TMP_DIR" rev-parse --short HEAD)
log_info "版本: $VERSION"

case "$REQUEST" in
  both)
    log_info "模式: both"
    install_layout codex
    install_layout claude
    ;;
  *)
    resolve_layout "$REQUEST"
    log_info "模式: $MODE"
    install_layout "$REQUEST"
    ;;
esac

# ---------- 汇总 ----------
echo ""
log_title "✅ 完成！"
echo ""
echo "  🧭 模式:     $REQUEST"
echo "  📁 目标目录: $INSTALLED_TARGETS"
echo "  📦 版本:     $VERSION"
echo ""
echo "  ✨ 新增: $TOTAL_NEW"
echo "  🔄 更新: ${TOTAL_UPDATED}（本地版本已备份为 .local.bak）"
echo "  🛡️  保留本地差异: $TOTAL_PRESERVED"
echo "  ⏭️  无变化: $TOTAL_SKIPPED"
echo ""

if [ "$TOTAL_UPDATED" -gt 0 ]; then
  log_warn "有 ${TOTAL_UPDATED} 个文件被更新，本地修改已备份为 .local.bak"
  log_warn "如需恢复本地版本: mv SKILL.md.local.bak SKILL.md"
  log_warn "如需对比差异:     diff SKILL.md SKILL.md.local.bak"
fi

if [ "$TOTAL_PRESERVED" -gt 0 ]; then
  log_warn "有 ${TOTAL_PRESERVED} 个本地改动文件被保护，远端新版已写入 *.upstream.new"
  log_warn "如需合并: diff SKILL.md SKILL.md.upstream.new"
  log_warn "如需强制覆盖: 重新运行并追加 --force-overwrite，或设置 SPEC_SKILLS_FORCE_OVERWRITE=1"
fi