#!/usr/bin/env sh
set -eu

# Sync project templates to target project.
# - Copies templates/memory-bank/ -> <project-root>/memory-bank/
# - Copies templates/prompts/ -> <project-root>/docs/prompts/
# - Copies templates/AGENTS.template.md -> <project-root>/AGENTS.md
# - Copies templates/AGENT_RULES.template.md -> <project-root>/AGENT_RULES.md
# Existing targets are backed up before overwrite.
#
# Usage:
#   sh scripts/sync_templates.sh                    # sync to current git root
#   sh scripts/sync_templates.sh -project-root /path/to/project
#   sh scripts/sync_templates.sh -project-root /path/to/project -project-name "MyProject" -date "2026-01-20"
#
# Options:
#   -project-root PATH    Target project root (default: git root)
#   -project-name NAME    Replace {{PROJECT_NAME}} placeholder
#   -date DATE            Replace {{DATE}} placeholder (default: today)
#   -no-backup            Skip backup of existing files
#   -force                Overwrite without prompting
#   -full                 Append full framework (规则优先级 + 新会话开始时) to existing AGENTS.md

SCRIPT_DIR="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd -P)"
SRC="$(CDPATH= cd -- "$SCRIPT_DIR/.." && pwd -P)"

# Defaults
PROJECT_NAME=""
SYNC_DATE="$(date +%Y-%m-%d 2>/dev/null || echo "{{DATE}}")"
NO_BACKUP=0
FORCE=0
FULL=0
PROJECT_ROOT=""

# Parse arguments
while [ $# -gt 0 ]; do
  case "$1" in
    -project-root)
      if [ $# -lt 2 ] || [ -z "${2:-}" ]; then
        echo "ERROR: -project-root requires a path." >&2
        exit 1
      fi
      PROJECT_ROOT="$2"
      shift 2
      ;;
    -project-name)
      if [ $# -lt 2 ] || [ -z "${2:-}" ]; then
        echo "ERROR: -project-name requires a value." >&2
        exit 1
      fi
      PROJECT_NAME="$2"
      shift 2
      ;;
    -date)
      if [ $# -lt 2 ] || [ -z "${2:-}" ]; then
        echo "ERROR: -date requires a value." >&2
        exit 1
      fi
      SYNC_DATE="$2"
      shift 2
      ;;
    -no-backup)
      NO_BACKUP=1
      shift
      ;;
    -force)
      FORCE=1
      shift
      ;;
    -full)
      FULL=1
      shift
      ;;
    -h|-help)
      cat <<'EOF'
Usage:
  sh scripts/sync_templates.sh [options]
  sh scripts/sync_templates.sh -project-root /path/to/project

Options:
  -project-root PATH    Target project root (default: git root)
  -project-name NAME    Replace {{PROJECT_NAME}} placeholder
  -date DATE            Replace {{DATE}} placeholder (default: today)
  -no-backup            Skip backup of existing files
  -force                Overwrite without prompting
  -full                 Append full framework (规则优先级 + 新会话开始时) to existing AGENTS.md
  -h, -help             Show this help

Examples:
  sh scripts/sync_templates.sh
  sh scripts/sync_templates.sh -project-root /path/to/project
  sh scripts/sync_templates.sh -project-root /path/to/project -full
EOF
      exit 0
      ;;
    -*)
      echo "ERROR: Unknown option: $1" >&2
      exit 1
      ;;
    *)
      echo "ERROR: positional args are not supported; use -project-root." >&2
      exit 1
      ;;
  esac
done

# Determine project root
if [ -z "$PROJECT_ROOT" ]; then
  PROJECT_ROOT="$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel 2>/dev/null || pwd)"
fi
PROJECT_ROOT="$(CDPATH= cd -- "$PROJECT_ROOT" && pwd -P)"

# Source directories
TEMPLATES_DIR="$SRC/templates"
MEMORY_BANK_SRC="$TEMPLATES_DIR/memory-bank"
PROMPTS_SRC="$TEMPLATES_DIR/prompts"
AGENTS_SRC="$TEMPLATES_DIR/AGENTS.template.md"
AGENT_RULES_SRC="$TEMPLATES_DIR/AGENT_RULES.template.md"

# Check source exists
if [ ! -d "$TEMPLATES_DIR" ]; then
  echo "ERROR: Templates directory not found: $TEMPLATES_DIR" >&2
  exit 1
fi

# Skip if source equals destination (running from playbook repo itself)
if [ "$SRC" = "$PROJECT_ROOT" ]; then
  echo "Skip: playbook root equals project root."
  echo "Done."
  exit 0
fi

timestamp="$(date +%Y%m%d%H%M%S 2>/dev/null || echo bak)"

# Function: backup file/directory
backup_if_exists() {
  target="$1"
  if [ -e "$target" ] && [ "$NO_BACKUP" -eq 0 ]; then
    backup="${target}.bak.$timestamp"
    mv "$target" "$backup"
    echo "Backed up: $(basename "$target") -> $(basename "$backup")"
  fi
}

escape_sed_replacement() {
  printf '%s' "$1" | sed 's/[&/|\\]/\\&/g'
}

# Function: replace placeholders in file
replace_placeholders() {
  file="$1"
  [ -f "$file" ] || return 0

  tmp="$(mktemp 2>/dev/null || echo "$file.tmp.$timestamp")"
  date_repl="$(escape_sed_replacement "$SYNC_DATE")"
  if [ -n "$PROJECT_NAME" ]; then
    project_repl="$(escape_sed_replacement "$PROJECT_NAME")"
    sed -e "s/{{PROJECT_NAME}}/$project_repl/g" -e "s/{{DATE}}/$date_repl/g" "$file" > "$tmp"
  else
    sed -e "s/{{DATE}}/$date_repl/g" "$file" > "$tmp"
  fi
  mv "$tmp" "$file"
}

# Function: replace placeholders in directory
replace_placeholders_dir() {
  dir="$1"
  [ -d "$dir" ] || return 0

  find "$dir" -type f -name '*.md' -print | while IFS= read -r file; do
    replace_placeholders "$file"
  done
}

echo "Syncing templates to: $PROJECT_ROOT"
echo ""

# 1. Sync memory-bank/
if [ -d "$MEMORY_BANK_SRC" ]; then
  MEMORY_BANK_DST="$PROJECT_ROOT/memory-bank"

  if [ -e "$MEMORY_BANK_DST" ] && [ "$FORCE" -eq 0 ]; then
    echo "memory-bank/ already exists. Use -force to overwrite."
  else
    backup_if_exists "$MEMORY_BANK_DST"
    mkdir -p "$MEMORY_BANK_DST"
    cp -R "$MEMORY_BANK_SRC"/* "$MEMORY_BANK_DST/" 2>/dev/null || true

    # Rename .template.md to .md
    for f in "$MEMORY_BANK_DST"/*.template.md; do
      [ -f "$f" ] || continue
      newname="$(echo "$f" | sed 's/\.template\.md$/.md/')"
      mv "$f" "$newname"
    done

    replace_placeholders_dir "$MEMORY_BANK_DST"
    echo "Synced: memory-bank/"
  fi
else
  echo "Skip: memory-bank/ templates not found"
fi

# 2. Sync docs/prompts/
if [ -d "$PROMPTS_SRC" ]; then
  PROMPTS_DST="$PROJECT_ROOT/docs/prompts"

  if [ -e "$PROMPTS_DST" ] && [ "$FORCE" -eq 0 ]; then
    echo "docs/prompts/ already exists. Use -force to overwrite."
  else
    backup_if_exists "$PROMPTS_DST"
    mkdir -p "$PROJECT_ROOT/docs"
    mkdir -p "$PROMPTS_DST"
    cp -R "$PROMPTS_SRC"/* "$PROMPTS_DST/" 2>/dev/null || true

    # Rename .template.md to .md (recursive)
    find "$PROMPTS_DST" -type f -name '*.template.md' -print | while IFS= read -r f; do
      newname="$(echo "$f" | sed 's/\.template\.md$/.md/')"
      mv "$f" "$newname"
    done

    replace_placeholders_dir "$PROMPTS_DST"
    echo "Synced: docs/prompts/"
  fi
else
  echo "Skip: prompts/ templates not found"
fi

# 3. Sync AGENTS.md
# Choose markers based on -full flag
if [ "$FULL" -eq 1 ]; then
  MARKER_START="<!-- playbook:framework:start -->"
  MARKER_END="<!-- playbook:framework:end -->"
  SECTION_NAME="framework"
else
  MARKER_START="<!-- playbook:templates:start -->"
  MARKER_END="<!-- playbook:templates:end -->"
  SECTION_NAME="templates"
fi

if [ -f "$AGENTS_SRC" ]; then
  AGENTS_DST="$PROJECT_ROOT/AGENTS.md"

  if [ ! -e "$AGENTS_DST" ]; then
    # AGENTS.md doesn't exist: create from full template
    cp "$AGENTS_SRC" "$AGENTS_DST"
    replace_placeholders "$AGENTS_DST"
    echo "Created: AGENTS.md"
  else
    # AGENTS.md exists: update or append section
    # Extract snippet from template
    snippet_content="$(awk -v start="$MARKER_START" -v end="$MARKER_END" '
      $0 ~ start { found=1 }
      found { print }
      $0 ~ end { found=0 }
    ' "$AGENTS_SRC")"

    if [ -z "$snippet_content" ]; then
      echo "Skip: markers not found in template"
    elif grep -q "$MARKER_START" "$AGENTS_DST"; then
      # Has markers: replace content between markers in place
      snippet_tmp="$(mktemp 2>/dev/null || echo "$AGENTS_DST.snippet.$timestamp")"
      printf "%s\n" "$snippet_content" > "$snippet_tmp"
      tmp="$(mktemp 2>/dev/null || echo "$AGENTS_DST.tmp.$timestamp")"
      awk -v start="$MARKER_START" -v end="$MARKER_END" -v snippet="$snippet_tmp" '
        BEGIN {
          while ((getline line < snippet) > 0) { block[++n] = line }
          close(snippet)
          inblock = 0
          replaced = 0
        }
        {
          if (!replaced && $0 ~ start) {
            for (i=1; i<=n; i++) print block[i]
            inblock = 1
            replaced = 1
            next
          }
          if (inblock) {
            if ($0 ~ end) { inblock = 0 }
            next
          }
          print
        }
      ' "$AGENTS_DST" > "$tmp"
      mv "$tmp" "$AGENTS_DST"
      rm -f "$snippet_tmp"
      replace_placeholders "$AGENTS_DST"
      echo "Updated: AGENTS.md ($SECTION_NAME section)"
    else
      # No markers: append snippet at the end
      echo "" >> "$AGENTS_DST"
      echo "$snippet_content" >> "$AGENTS_DST"
      replace_placeholders "$AGENTS_DST"
      echo "Appended: AGENTS.md ($SECTION_NAME section)"
    fi
  fi
else
  echo "Skip: AGENTS.template.md not found"
fi

# 4. Sync AGENT_RULES.md
if [ -f "$AGENT_RULES_SRC" ]; then
  AGENT_RULES_DST="$PROJECT_ROOT/AGENT_RULES.md"

  if [ -e "$AGENT_RULES_DST" ] && [ "$FORCE" -eq 0 ]; then
    echo "AGENT_RULES.md already exists. Use -force to overwrite."
  else
    backup_if_exists "$AGENT_RULES_DST"
    cp "$AGENT_RULES_SRC" "$AGENT_RULES_DST"
    replace_placeholders "$AGENT_RULES_DST"
    echo "Synced: AGENT_RULES.md"
  fi
else
  echo "Skip: AGENT_RULES.template.md not found"
fi

# 5. Create TODO.md and CONFIRM.md if not exist
if [ ! -f "$PROJECT_ROOT/TODO.md" ]; then
  cat > "$PROJECT_ROOT/TODO.md" <<'EOF'
# TODO

## Plan 1: [计划名称]

- [ ] 任务 1
- [ ] 任务 2

---

**最后更新**：{{DATE}}
EOF
  date_repl="$(escape_sed_replacement "$SYNC_DATE")"
  if ! sed -i "s/{{DATE}}/$date_repl/g" "$PROJECT_ROOT/TODO.md" 2>/dev/null; then
    sed "s/{{DATE}}/$date_repl/g" "$PROJECT_ROOT/TODO.md" > "$PROJECT_ROOT/TODO.md.tmp"
    mv "$PROJECT_ROOT/TODO.md.tmp" "$PROJECT_ROOT/TODO.md"
  fi
  echo "Created: TODO.md"
fi

if [ ! -f "$PROJECT_ROOT/CONFIRM.md" ]; then
  cat > "$PROJECT_ROOT/CONFIRM.md" <<'EOF'
# 待确认事项

## 待确认

<!-- 记录需要确认的事项 -->

## 已确认

<!-- 已确认的事项移到这里 -->

---

**最后更新**：{{DATE}}
EOF
  date_repl="$(escape_sed_replacement "$SYNC_DATE")"
  if ! sed -i "s/{{DATE}}/$date_repl/g" "$PROJECT_ROOT/CONFIRM.md" 2>/dev/null; then
    sed "s/{{DATE}}/$date_repl/g" "$PROJECT_ROOT/CONFIRM.md" > "$PROJECT_ROOT/CONFIRM.md.tmp"
    mv "$PROJECT_ROOT/CONFIRM.md.tmp" "$PROJECT_ROOT/CONFIRM.md"
  fi
  echo "Created: CONFIRM.md"
fi

echo ""
echo "Done."
echo ""
echo "Next steps:"
echo "  1. Edit memory-bank/*.md to fill in project-specific content"
echo "  2. Replace remaining {{PLACEHOLDER}} values"
echo "  3. Run sync_standards.sh -langs <lang> to sync .agents/ rules"