#!/usr/bin/env bash

# Exit on error, undefined variables, and pipe failures
set -euo pipefail

show_help() {
  cat << EOF
Usage: $(basename "$0") [options] <note_name_or_path>

Create a new note in your Obsidian vault.

Options:
  -v, --vault <dir>      Specify the Obsidian vault directory.
  --overwrite            Overwrite the file if it already exists.
  -h, --help             Show this help message.
EOF
}

VAULT_DIR=""
OVERWRITE="false"
NOTE_PATH=""

# Parse arguments
while [[ $# -gt 0 ]]; do
  case "$1" in
    -v|--vault)
      if [[ -z "${2:-}" ]]; then
        echo "Error: --vault requires a directory path." >&2
        exit 1
      fi
      VAULT_DIR="$2"
      shift 2
      ;;
    --overwrite)
      OVERWRITE="true"
      shift
      ;;
    -h|--help)
      show_help
      exit 0
      ;;
    -*)
      echo "Error: Unknown option: $1" >&2
      show_help
      exit 1
      ;;
    *)
      if [[ -n "$NOTE_PATH" ]]; then
        echo "Error: Multiple note paths provided: $NOTE_PATH and $1" >&2
        exit 1
      fi
      NOTE_PATH="$1"
      shift
      ;;
  esac
done

if [[ -z "$NOTE_PATH" ]]; then
  echo "Error: Missing note path/name." >&2
  show_help
  exit 1
fi

# 1. Find the Obsidian vault.
if [[ -n "$VAULT_DIR" ]]; then
  # -v/--vault was passed. Check that the directory exists and contains a .obsidian directory.
  if [[ ! -d "$VAULT_DIR" ]]; then
    echo "Error: Specified vault directory does not exist: $VAULT_DIR" >&2
    exit 1
  fi
  if [[ ! -d "$VAULT_DIR/.obsidian" ]]; then
    echo "Error: Specified directory is not an Obsidian vault (missing .obsidian): $VAULT_DIR" >&2
    exit 1
  fi
  VAULT_DIR="$(cd "$VAULT_DIR" && pwd)"
else
  # Search directories upward for a parent (or current) directory containing a .obsidian subdirectory.
  # Stop at the user's home directory or a filesystem boundary.
  CURRENT_DIR="$PWD"
  FOUND_VAULT=""

  get_device_id() {
    local dir="$1"
    if [[ "$(uname)" == "Darwin" ]]; then
      stat -f '%d' "$dir" 2>/dev/null || echo ""
    else
      stat -c '%d' "$dir" 2>/dev/null || echo ""
    fi
  }

  CURRENT_DEV="$(get_device_id "$CURRENT_DIR")"

  while [[ "$CURRENT_DIR" != "/" && "$CURRENT_DIR" != "$HOME" ]]; do
    if [[ -d "$CURRENT_DIR/.obsidian" ]]; then
      FOUND_VAULT="$CURRENT_DIR"
      break
    fi

    PARENT_DIR="$(dirname "$CURRENT_DIR")"
    if [[ "$PARENT_DIR" == "$CURRENT_DIR" ]]; then
      break
    fi

    # Check filesystem boundary
    PARENT_DEV="$(get_device_id "$PARENT_DIR")"
    if [[ -n "$CURRENT_DEV" && -n "$PARENT_DEV" && "$CURRENT_DEV" != "$PARENT_DEV" ]]; then
      break
    fi

    CURRENT_DIR="$PARENT_DIR"
    CURRENT_DEV="$PARENT_DEV"
  done

  # Check the last checked directory (could be HOME or /)
  if [[ -z "$FOUND_VAULT" && -d "$CURRENT_DIR/.obsidian" ]]; then
    FOUND_VAULT="$CURRENT_DIR"
  fi

  if [[ -n "$FOUND_VAULT" ]]; then
    VAULT_DIR="$FOUND_VAULT"
  else
    # Fallback paths in order: ~/Notes, ~/Obsidian/Notes, ~/Personal/Notes, ~/Projects/Notes.
    FALLBACKS=(
      "$HOME/Notes"
      "$HOME/Obsidian/Notes"
      "$HOME/Personal/Notes"
      "$HOME/Projects/Notes"
    )
    for path in "${FALLBACKS[@]}"; do
      if [[ -d "$path" && -d "$path/.obsidian" ]]; then
        VAULT_DIR="$(cd "$path" && pwd)"
        break
      fi
    done
  fi
fi

if [[ -z "$VAULT_DIR" ]]; then
  echo "Error: Could not find an Obsidian vault. Please specify one with -v/--vault." >&2
  exit 1
fi

# Strip leading slash from NOTE_PATH to handle relative paths properly
NOTE_PATH="${NOTE_PATH#/}"

# 2. Determine if current working directory is within the vault.
# Resolve physical paths to handle symlinks cleanly.
RESOLVED_PWD="$(pwd -P)"
RESOLVED_VAULT="$(cd "$VAULT_DIR" && pwd -P)"

if [[ "$RESOLVED_PWD" == "$RESOLVED_VAULT" || "$RESOLVED_PWD" == "$RESOLVED_VAULT"/* ]]; then
  # Within the vault, treat relative to CWD
  TARGET_FILE="$PWD/$NOTE_PATH"
else
  # Not within the vault, treat relative to vault root
  TARGET_FILE="$VAULT_DIR/$NOTE_PATH"
fi

TARGET_DIR="$(dirname "$TARGET_FILE")"
TARGET_BASE="$(basename "$TARGET_FILE")"

# If there's no file extension on the argument, add .md.
if [[ "$TARGET_BASE" != *.* ]]; then
  TARGET_BASE="$TARGET_BASE.md"
fi

TARGET_FILE="$TARGET_DIR/$TARGET_BASE"

# If the necessary directory components don't exist, create them.
if [[ ! -d "$TARGET_DIR" ]]; then
  mkdir -p "$TARGET_DIR"
fi

# 3. If the file exists and there's no --overwrite argument, throw an error.
if [[ -f "$TARGET_FILE" && "$OVERWRITE" != "true" ]]; then
  echo "Error: File already exists: $TARGET_FILE (use --overwrite to replace it)" >&2
  exit 1
fi

# 4. If the path ends in .md (case-insensitive), generate appropriate YAML front matter and write it to the new file.
if [[ "${TARGET_BASE,,}" == *.md ]]; then
  NOTE_TITLE="${TARGET_BASE%.*}"
  CURRENT_DATE="$(date +"%Y-%m-%d %H:%M")"

  cat << EOF > "$TARGET_FILE"
---
title: "$NOTE_TITLE"
date: $CURRENT_DATE
tags: []
---

EOF
else
  # Just touch the file to ensure it exists
  touch "$TARGET_FILE"
fi

# 5. Open the user's $EDITOR (falling back to vim/vi if unset) pointing to the new file.
EDITOR="${EDITOR:-}"
if [[ -z "$EDITOR" ]]; then
  if command -v vim >/dev/null 2>&1; then
    EDITOR="vim"
  else
    EDITOR="vi"
  fi
fi

exec "$EDITOR" "$TARGET_FILE"