#!/usr/bin/env python3
"""
LED Bar Configuration CLI Tool

Command-line interface for downloading, editing, and uploading settings.json
to/from MicroPython devices via mpremote.
"""

import json
import argparse
import subprocess
import sys
import time
from typing import Dict, Any, List, Optional

import tempfile
import os
from device import copy_file, DeviceConnection


def resolve_flash_binary(path: str) -> Optional[str]:
    """Resolve binary path: full path or in bin/ directory."""
    if os.path.isabs(path):
        return path if os.path.exists(path) else None
    if os.path.exists(path):
        return os.path.abspath(path)
    bin_path = os.path.join("bin", path)
    return os.path.abspath(bin_path) if os.path.exists(bin_path) else None


def download_settings(device: str) -> dict:
    """
    Download settings.json from the device.

    Returns an empty dict if the file does not exist so that the tool
    can be used on a fresh device before settings.json has been created.
    """
    temp_file = tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False)
    temp_path = temp_file.name
    temp_file.close()

    try:
        copy_file(from_device=True, device=device, remote_path="settings.json", local_path=temp_path)
        with open(temp_path, "r", encoding="utf-8") as f:
            return json.load(f)
    except (OSError, RuntimeError) as e:
        # If the file is missing on the device, treat it as empty settings
        msg = str(e).lower()
        if "errno 2" in msg or "enoent" in msg or "not found" in msg:
            return {}
        raise
    finally:
        if os.path.exists(temp_path):
            try:
                os.unlink(temp_path)
            except OSError:
                pass


def upload_settings(device: str, settings: dict) -> None:
    """Upload settings.json to the device and reset device."""
    temp_file = tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False)
    temp_path = temp_file.name

    try:
        json.dump(settings, temp_file, indent=2)
        temp_file.close()

        copy_file(from_device=False, device=device, remote_path="settings.json", local_path=temp_path)

        # Reset device (best effort)
        try:
            conn = DeviceConnection(device)
            conn.connect()
            conn.reset()
            conn.disconnect()
        except Exception:
            pass
    finally:
        if os.path.exists(temp_path):
            try:
                os.unlink(temp_path)
            except OSError:
                pass


def print_settings(settings: Dict[str, Any]) -> None:
    """Pretty print settings dictionary."""
    print(json.dumps(settings, indent=2))


# Flags that consume the next argv as their value (for skipping during order scan)
_FLAGS_WITH_VALUE = frozenset({
    '-p', '--port', '-n', '--name', '--pin', '-b', '--brightness',
    '-l', '--leds', '-d', '-debug', '--debug', '-o', '--order',
    '--preset', '--default',
})


def _get_ordered_actions(argv: List[str]) -> List[tuple]:
    """
    Scan argv and return list of (action_name, value) in order of appearance.
    Actions: flash, pause, reset, upload, erase_all, rm, follow.
    """
    actions = []
    i = 1
    while i < len(argv):
        arg = argv[i]
        if arg == '--pause':
            if i + 1 < len(argv):
                try:
                    secs = float(argv[i + 1])
                    actions.append(('pause', secs))
                except ValueError:
                    raise ValueError("--pause requires a number (seconds)")
                i += 2
            else:
                raise ValueError("--pause requires an argument")
            continue
        if arg == '--flash':
            if i + 1 < len(argv):
                actions.append(('flash', argv[i + 1]))
                i += 2
            else:
                raise ValueError("--flash requires an argument")
            continue
        if arg in ('-r', '--reset'):
            actions.append(('reset', None))
            i += 1
            continue
        if arg in ('-u', '--upload'):
            vals = []
            i += 1
            while i < len(argv) and not argv[i].startswith('-'):
                vals.append(argv[i])
                i += 1
                if len(vals) >= 2:
                    break
            if vals:
                actions.append(('upload', vals))
            continue
        if arg == '--src':
            # Upload local DIR (default: ./src) to device root (:/
            local_dir = "src"
            if i + 1 < len(argv) and not argv[i + 1].startswith('-'):
                local_dir = argv[i + 1]
                i += 2
            else:
                i += 1
            # Use empty string as remote_dir to map to root on device
            actions.append(('upload', [local_dir, ""]))
            continue
        if arg == '--lib':
            # Upload local DIR to /lib on device
            if i + 1 < len(argv):
                local_dir = argv[i + 1]
                actions.append(('upload', [local_dir, "lib"]))
                i += 2
            else:
                raise ValueError("--lib requires a directory argument")
            continue
        if arg == '-e':
            actions.append(('erase_all', None))
            i += 1
            continue
        if arg == '--rm':
            if i + 1 < len(argv):
                actions.append(('rm', argv[i + 1]))
                i += 2
            else:
                raise ValueError("--rm requires an argument")
            continue
        if arg in ('-f', '--follow'):
            # Optional duration in seconds: --follow [SECONDS]
            follow_secs = None
            if i + 1 < len(argv) and not argv[i + 1].startswith('-'):
                try:
                    follow_secs = float(argv[i + 1])
                    i += 2
                except ValueError:
                    # Not a number, treat as flag-only
                    i += 1
                actions.append(('follow', follow_secs))
            else:
                actions.append(('follow', None))
                i += 1
            continue
        # Skip non-action flags and their values
        if arg in _FLAGS_WITH_VALUE and i + 1 < len(argv):
            i += 2
        else:
            i += 1
    return actions


def main() -> None:
    parser = argparse.ArgumentParser(
        description="LED Bar Configuration CLI Tool",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Examples:
  # Download and print current settings
  %(prog)s

  # Download, edit device name and brightness, then upload
  %(prog)s -n "LED-Strip-1" -b 128

  # Set multiple parameters
  %(prog)s -n "MyLED" -b 200 --preset "rainbow"

  # Set number of LEDs, color order, and debug mode
  %(prog)s -l 60 -o rgb -d 1

  # Reset the device
  %(prog)s -r

  # Follow device output
  %(prog)s -f

  # Reset and then follow output
  %(prog)s -r -f

  # Flash firmware binary (full path or filename in bin/)
  %(prog)s --flash firmware.bin
  %(prog)s -p /dev/ttyUSB0 --flash /path/to/firmware.bin

  # Reset, pause 2 seconds, then follow output
  %(prog)s --reset --pause 2 --follow

  # Set name, num_leds, default pattern, and upload
  %(prog)s --name "MyStrip" -l 60 --default rainbow
        """
    )

    parser.add_argument(
        "-p", "--port",
        default="/dev/ttyACM0",
        help="Serial port/device path (default: /dev/ttyACM0)"
    )

    parser.add_argument(
        "-n", "--name",
        help="Device name"
    )

    parser.add_argument(
        "--pin",
        type=int,
        metavar="N",
        help="LED GPIO pin number (led_pin in settings.json)"
    )

    parser.add_argument(
        "-b", "--brightness",
        type=int,
        metavar="0-255",
        help="Brightness (0-255)"
    )

    parser.add_argument(
        "-l", "--leds",
        dest="leds",
        type=int,
        metavar="N",
        help="Number of LEDs (num_leds in settings.json)"
    )

    parser.add_argument(
        "-d", "-debug", "--debug",
        dest="debug",
        type=int,
        choices=[0, 1],
        metavar="0|1",
        help="Debug mode (0 or 1)"
    )

    parser.add_argument(
        "-o", "--order",
        dest="color_order",
        choices=["rgb", "rbg", "grb", "gbr", "brg", "bgr"],
        help="Color order (rgb, rbg, grb, gbr, brg, bgr)"
    )

    parser.add_argument(
        "--preset",
        help="Pattern preset name"
    )

    parser.add_argument(
        "--default",
        metavar="PATTERN",
        help="Default/startup pattern (stored as 'default' in settings.json)"
    )

    parser.add_argument(
        "--pause",
        type=float,
        metavar="SECONDS",
        help="Pause for N seconds (use in action sequence, e.g. --reset --pause 2 --follow)"
    )

    parser.add_argument(
        "-r", "--reset",
        action="store_true",
        help="Reset the device"
    )

    parser.add_argument(
        "-f", "--follow",
        nargs="?",
        const=None,
        type=float,
        metavar="SECONDS",
        help="Follow device output continuously (like tail -f). Optionally specify SECONDS to limit follow duration."
    )

    parser.add_argument(
        "-s", "--show",
        action="store_true",
        help="Display current settings from device"
    )

    parser.add_argument(
        "-u", "--upload",
        nargs='+',
        metavar=("SRC", "DEST"),
        help="Upload a directory recursively to the device. Usage: -u SRC [DEST] (DEST is optional, defaults to basename of SRC)"
    )

    parser.add_argument(
        "--src",
        nargs="?",
        const="src",
        metavar="DIR",
        help="Upload DIR recursively to device root (:/, no leading directory). If DIR is omitted, uses local ./src."
    )

    parser.add_argument(
        "--lib",
        metavar="DIR",
        help="Upload DIR recursively to /lib on device"
    )

    parser.add_argument(
        "-e",
        dest="erase_all",
        action="store_true",
        help="Erase all code on the device (delete all files except settings.json)"
    )

    parser.add_argument(
        "--rm",
        metavar="PATH",
        help="Delete a file or directory on the device (recursive for directories)"
    )

    parser.add_argument(
        "--flash",
        metavar="BINARY",
        help="Flash firmware binary to device. Path can be full path or filename in bin/"
    )

    try:
        args = parser.parse_args()
        ordered_actions = _get_ordered_actions(sys.argv)
    except ValueError as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(1)

    port = args.port
    ran_reset = False

    # Execute actions in command-line order
    for action_name, value in ordered_actions:
        if action_name == 'pause':
            print(f"Pausing for {value} seconds...", file=sys.stderr)
            time.sleep(value)
        elif action_name == 'flash':
            resolved = resolve_flash_binary(value)
            if not resolved:
                print(f"Error: binary not found: {value} (checked bin/)", file=sys.stderr)
                sys.exit(1)
            try:
                print(f"Erasing flash on {port}...", file=sys.stderr)
                subprocess.run(["esptool", "-p", port, "erase_flash"], check=True)
                print(f"Writing {resolved} to flash at 0...", file=sys.stderr)
                subprocess.run(["esptool", "-p", port, "write_flash", "0", resolved], check=True)
                print("Flash complete.", file=sys.stderr)
                print("Waiting 2s for device to boot...", file=sys.stderr)
                time.sleep(2)
            except subprocess.CalledProcessError as e:
                print(f"Error flashing: {e}", file=sys.stderr)
                sys.exit(1)
            except FileNotFoundError:
                print("Error: esptool not found. Install it with: pip install esptool", file=sys.stderr)
                sys.exit(1)

        elif action_name == 'reset':
            ran_reset = True
            try:
                print(f"Resetting device on {port}...", file=sys.stderr)
                conn = DeviceConnection(port)
                conn.reset()
                print("Device reset.", file=sys.stderr)
            except Exception as e:
                print(f"Error resetting device: {e}", file=sys.stderr)
                sys.exit(1)

        elif action_name == 'upload':
            if len(value) > 2:
                print("Error: -u accepts at most 2 arguments (source and optional destination)", file=sys.stderr)
                sys.exit(1)
            upload_dir = value[0]
            remote_dir = value[1] if len(value) > 1 else None
            if not os.path.exists(upload_dir):
                print(f"Error: Directory does not exist: {upload_dir}", file=sys.stderr)
                sys.exit(1)
            if not os.path.isdir(upload_dir):
                print(f"Error: Not a directory: {upload_dir}", file=sys.stderr)
                sys.exit(1)
            try:
                if remote_dir:
                    print(f"Uploading {upload_dir} to {remote_dir} on device {port}...", file=sys.stderr)
                else:
                    print(f"Uploading {upload_dir} to device on {port}...", file=sys.stderr)
                conn = DeviceConnection(port)
                files_copied, dirs_created = conn.upload_directory(upload_dir, remote_dir)
                print(f"Upload complete: {files_copied} files, {dirs_created} directories created.", file=sys.stderr)
            except Exception as e:
                print(f"Error uploading directory: {e}", file=sys.stderr)
                sys.exit(1)

        elif action_name == 'erase_all':
            try:
                print(f"Erasing all code on device {port}...", file=sys.stderr)
                conn = DeviceConnection(port)
                items = conn.list_files('')
                for name, is_dir, size in items:
                    if name == "settings.json":
                        continue
                    conn.delete(name)
                print("Erase complete.", file=sys.stderr)
            except Exception as e:
                print(f"Error erasing device: {e}", file=sys.stderr)
                sys.exit(1)

        elif action_name == 'rm':
            try:
                print(f"Deleting {value} on device {port}...", file=sys.stderr)
                conn = DeviceConnection(port)
                conn.delete(value)
                print(f"Successfully deleted: {value}", file=sys.stderr)
            except Exception as e:
                print(f"Error deleting {value}: {e}", file=sys.stderr)
                sys.exit(1)

        elif action_name == 'follow':
            if ran_reset:
                time.sleep(0.5)
            try:
                if value is None:
                    print(f"Following output from {port}... (Press Ctrl+C to stop)", file=sys.stderr)
                else:
                    print(f"Following output from {port} for {value} seconds...", file=sys.stderr)
                conn = DeviceConnection(port)
                conn.follow_output(value)
            except KeyboardInterrupt:
                print("\nStopped following.", file=sys.stderr)
                sys.exit(0)
            except Exception as e:
                print(f"Error following output: {e}", file=sys.stderr)
                sys.exit(1)
            return  # follow blocks; when interrupted we're done

    # Collect all edit parameters
    edits: Dict[str, Any] = {}

    if args.name is not None:
        edits["name"] = args.name

    if args.pin is not None:
        edits["led_pin"] = args.pin

    if args.brightness is not None:
        edits["brightness"] = args.brightness

    if args.leds is not None:
        edits["num_leds"] = args.leds

    if args.debug is not None:
        edits["debug"] = bool(args.debug)

    if args.color_order is not None:
        edits["color_order"] = args.color_order

    if args.preset is not None:
        edits["pattern"] = args.preset

    if args.default is not None:
        edits["default"] = args.default

    # 1. Download: get current settings from device
    try:
        print(f"Downloading settings from {args.port}...", file=sys.stderr)
        settings = download_settings(args.port)
        print("Settings downloaded successfully.", file=sys.stderr)
    except Exception as e:
        if "timeout" in str(e).lower() or "connection" in str(e).lower():
            print(f"Error: Connection timeout. Check device connection on {args.port}", file=sys.stderr)
        else:
            print(f"Error downloading settings: {e}", file=sys.stderr)
        sys.exit(1)

    # If --show only, print and exit
    if args.show:
        print_settings(settings)
        if not edits:
            return

    # 2. Edit: apply edits to downloaded settings
    if edits:
        print(f"Applying {len(edits)} edit(s)...", file=sys.stderr)
        settings.update(edits)

    print_settings(settings)

    # 3. Upload: write settings back to device when edits were made
    if edits:
        try:
            print(f"\nUploading settings to {args.port}...", file=sys.stderr)
            upload_settings(args.port, settings)
            print("Settings uploaded successfully. Device will reset.", file=sys.stderr)
        except Exception as e:
            if "timeout" in str(e).lower() or "connection" in str(e).lower():
                print(f"Error: Connection timeout. Check device connection on {args.port}", file=sys.stderr)
            else:
                print(f"Error uploading settings: {e}", file=sys.stderr)
            sys.exit(1)


if __name__ == "__main__":
    main()