"""Hermes CLI skin/theme engine.

A data-driven skin system that lets users customize the CLI's visual appearance.
Skins are defined as YAML files in ~/.hermes/skins/ or as built-in presets.
No code changes are needed to add a new skin.

SKIN YAML SCHEMA
================

All fields are optional. Missing values inherit from the ``default`` skin.

.. code-block:: yaml

    # Required: skin identity
    name: mytheme                         # Unique skin name (lowercase, hyphens ok)
    description: Short description        # Shown in /skin listing

    # Colors: hex values for Rich markup (banner, UI, response box)
    colors:
      banner_border: "#CD7F32"            # Panel border color
      banner_title: "#FFD700"             # Panel title text color
      banner_accent: "#FFBF00"            # Section headers (Available Tools, etc.)
      banner_dim: "#B8860B"               # Dim/muted text (separators, labels)
      banner_text: "#FFF8DC"              # Body text (tool names, skill names)
      ui_accent: "#FFBF00"               # General UI accent
      ui_label: "#4dd0e1"                # UI labels
      ui_ok: "#4caf50"                   # Success indicators
      ui_error: "#ef5350"                # Error indicators
      ui_warn: "#ffa726"                 # Warning indicators
      prompt: "#FFF8DC"                  # Prompt text color
      input_rule: "#CD7F32"              # Input area horizontal rule
      response_border: "#FFD700"         # Response box border (ANSI)
      session_label: "#DAA520"           # Session label color
      session_border: "#8B8682"          # Session ID dim color

    # Spinner: customize the animated spinner during API calls
    spinner:
      waiting_faces:                      # Faces shown while waiting for API
        - "(⚔)"
        - "(⛨)"
      thinking_faces:                     # Faces shown during reasoning
        - "(⌁)"
        - "(<>)"
      thinking_verbs:                     # Verbs for spinner messages
        - "forging"
        - "plotting"
      wings:                              # Optional left/right spinner decorations
        - ["⟪⚔", "⚔⟫"]                  # Each entry is [left, right] pair
        - ["⟪▲", "▲⟫"]

    # Branding: text strings used throughout the CLI
    branding:
      agent_name: "Hermes Agent"          # Banner title, status display
      welcome: "Welcome message"          # Shown at CLI startup
      goodbye: "Goodbye! ⚕"              # Shown on exit
      response_label: " ⚕ Hermes "       # Response box header label
      prompt_symbol: "❯ "                # Input prompt symbol
      help_header: "(^_^)? Commands"      # /help header text

    # Tool prefix: character for tool output lines (default: ┊)
    tool_prefix: "┊"

USAGE
=====

.. code-block:: python

    from hermes_cli.skin_engine import get_active_skin, list_skins, set_active_skin

    skin = get_active_skin()
    print(skin.colors["banner_title"])    # "#FFD700"
    print(skin.get_branding("agent_name"))  # "Hermes Agent"

    set_active_skin("ares")               # Switch to built-in ares skin
    set_active_skin("mytheme")            # Switch to user skin from ~/.hermes/skins/

BUILT-IN SKINS
==============

- ``default`` — Classic Hermes gold/kawaii (the current look)
- ``ares``    — Crimson/bronze war-god theme with custom spinner wings
- ``mono``    — Clean grayscale monochrome
- ``slate``   — Cool blue developer-focused theme

USER SKINS
==========

Drop a YAML file in ``~/.hermes/skins/<name>.yaml`` following the schema above.
Activate with ``/skin <name>`` in the CLI or ``display.skin: <name>`` in config.yaml.
"""

import logging
import os
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any, Dict, List, Optional, Tuple

logger = logging.getLogger(__name__)


# =============================================================================
# Skin data structure
# =============================================================================

@dataclass
class SkinConfig:
    """Complete skin configuration."""
    name: str
    description: str = ""
    colors: Dict[str, str] = field(default_factory=dict)
    spinner: Dict[str, Any] = field(default_factory=dict)
    branding: Dict[str, str] = field(default_factory=dict)
    tool_prefix: str = "┊"

    def get_color(self, key: str, fallback: str = "") -> str:
        """Get a color value with fallback."""
        return self.colors.get(key, fallback)

    def get_spinner_list(self, key: str) -> List[str]:
        """Get a spinner list (faces, verbs, etc.)."""
        return self.spinner.get(key, [])

    def get_spinner_wings(self) -> List[Tuple[str, str]]:
        """Get spinner wing pairs, or empty list if none."""
        raw = self.spinner.get("wings", [])
        result = []
        for pair in raw:
            if isinstance(pair, (list, tuple)) and len(pair) == 2:
                result.append((str(pair[0]), str(pair[1])))
        return result

    def get_branding(self, key: str, fallback: str = "") -> str:
        """Get a branding value with fallback."""
        return self.branding.get(key, fallback)


# =============================================================================
# Built-in skin definitions
# =============================================================================

_BUILTIN_SKINS: Dict[str, Dict[str, Any]] = {
    "default": {
        "name": "default",
        "description": "Classic Hermes — gold and kawaii",
        "colors": {
            "banner_border": "#CD7F32",
            "banner_title": "#FFD700",
            "banner_accent": "#FFBF00",
            "banner_dim": "#B8860B",
            "banner_text": "#FFF8DC",
            "ui_accent": "#FFBF00",
            "ui_label": "#4dd0e1",
            "ui_ok": "#4caf50",
            "ui_error": "#ef5350",
            "ui_warn": "#ffa726",
            "prompt": "#FFF8DC",
            "input_rule": "#CD7F32",
            "response_border": "#FFD700",
            "session_label": "#DAA520",
            "session_border": "#8B8682",
        },
        "spinner": {
            # Empty = use hardcoded defaults in display.py
        },
        "branding": {
            "agent_name": "Hermes Agent",
            "welcome": "Welcome to Hermes Agent! Type your message or /help for commands.",
            "goodbye": "Goodbye! ⚕",
            "response_label": " ⚕ Hermes ",
            "prompt_symbol": "❯ ",
            "help_header": "(^_^)? Available Commands",
        },
        "tool_prefix": "┊",
    },
    "ares": {
        "name": "ares",
        "description": "War-god theme — crimson and bronze",
        "colors": {
            "banner_border": "#9F1C1C",
            "banner_title": "#C7A96B",
            "banner_accent": "#DD4A3A",
            "banner_dim": "#6B1717",
            "banner_text": "#F1E6CF",
            "ui_accent": "#DD4A3A",
            "ui_label": "#C7A96B",
            "ui_ok": "#4caf50",
            "ui_error": "#ef5350",
            "ui_warn": "#ffa726",
            "prompt": "#F1E6CF",
            "input_rule": "#9F1C1C",
            "response_border": "#C7A96B",
            "session_label": "#C7A96B",
            "session_border": "#6E584B",
        },
        "spinner": {
            "waiting_faces": ["(⚔)", "(⛨)", "(▲)", "(<>)", "(/)"],
            "thinking_faces": ["(⚔)", "(⛨)", "(▲)", "(⌁)", "(<>)"],
            "thinking_verbs": [
                "forging", "marching", "sizing the field", "holding the line",
                "hammering plans", "tempering steel", "plotting impact", "raising the shield",
            ],
            "wings": [
                ["⟪⚔", "⚔⟫"],
                ["⟪▲", "▲⟫"],
                ["⟪╸", "╺⟫"],
                ["⟪⛨", "⛨⟫"],
            ],
        },
        "branding": {
            "agent_name": "Ares Agent",
            "welcome": "Welcome to Ares Agent! Type your message or /help for commands.",
            "goodbye": "Farewell, warrior! ⚔",
            "response_label": " ⚔ Ares ",
            "prompt_symbol": "⚔ ❯ ",
            "help_header": "(⚔) Available Commands",
        },
        "tool_prefix": "╎",
    },
    "mono": {
        "name": "mono",
        "description": "Monochrome — clean grayscale",
        "colors": {
            "banner_border": "#555555",
            "banner_title": "#e6edf3",
            "banner_accent": "#aaaaaa",
            "banner_dim": "#444444",
            "banner_text": "#c9d1d9",
            "ui_accent": "#aaaaaa",
            "ui_label": "#888888",
            "ui_ok": "#888888",
            "ui_error": "#cccccc",
            "ui_warn": "#999999",
            "prompt": "#c9d1d9",
            "input_rule": "#444444",
            "response_border": "#aaaaaa",
            "session_label": "#888888",
            "session_border": "#555555",
        },
        "spinner": {},
        "branding": {
            "agent_name": "Hermes Agent",
            "welcome": "Welcome to Hermes Agent! Type your message or /help for commands.",
            "goodbye": "Goodbye! ⚕",
            "response_label": " ⚕ Hermes ",
            "prompt_symbol": "❯ ",
            "help_header": "[?] Available Commands",
        },
        "tool_prefix": "┊",
    },
    "slate": {
        "name": "slate",
        "description": "Cool blue — developer-focused",
        "colors": {
            "banner_border": "#4169e1",
            "banner_title": "#7eb8f6",
            "banner_accent": "#8EA8FF",
            "banner_dim": "#4b5563",
            "banner_text": "#c9d1d9",
            "ui_accent": "#7eb8f6",
            "ui_label": "#8EA8FF",
            "ui_ok": "#63D0A6",
            "ui_error": "#F7A072",
            "ui_warn": "#e6a855",
            "prompt": "#c9d1d9",
            "input_rule": "#4169e1",
            "response_border": "#7eb8f6",
            "session_label": "#7eb8f6",
            "session_border": "#4b5563",
        },
        "spinner": {},
        "branding": {
            "agent_name": "Hermes Agent",
            "welcome": "Welcome to Hermes Agent! Type your message or /help for commands.",
            "goodbye": "Goodbye! ⚕",
            "response_label": " ⚕ Hermes ",
            "prompt_symbol": "❯ ",
            "help_header": "(^_^)? Available Commands",
        },
        "tool_prefix": "┊",
    },
}


# =============================================================================
# Skin loading and management
# =============================================================================

_active_skin: Optional[SkinConfig] = None
_active_skin_name: str = "default"


def _skins_dir() -> Path:
    """User skins directory."""
    home = Path(os.getenv("HERMES_HOME", Path.home() / ".hermes"))
    return home / "skins"


def _load_skin_from_yaml(path: Path) -> Optional[Dict[str, Any]]:
    """Load a skin definition from a YAML file."""
    try:
        import yaml
        with open(path, "r", encoding="utf-8") as f:
            data = yaml.safe_load(f)
        if isinstance(data, dict) and "name" in data:
            return data
    except Exception as e:
        logger.debug("Failed to load skin from %s: %s", path, e)
    return None


def _build_skin_config(data: Dict[str, Any]) -> SkinConfig:
    """Build a SkinConfig from a raw dict (built-in or loaded from YAML)."""
    # Start with default values as base for missing keys
    default = _BUILTIN_SKINS["default"]
    colors = dict(default.get("colors", {}))
    colors.update(data.get("colors", {}))
    spinner = dict(default.get("spinner", {}))
    spinner.update(data.get("spinner", {}))
    branding = dict(default.get("branding", {}))
    branding.update(data.get("branding", {}))

    return SkinConfig(
        name=data.get("name", "unknown"),
        description=data.get("description", ""),
        colors=colors,
        spinner=spinner,
        branding=branding,
        tool_prefix=data.get("tool_prefix", default.get("tool_prefix", "┊")),
    )


def list_skins() -> List[Dict[str, str]]:
    """List all available skins (built-in + user-installed).

    Returns list of {"name": ..., "description": ..., "source": "builtin"|"user"}.
    """
    result = []
    for name, data in _BUILTIN_SKINS.items():
        result.append({
            "name": name,
            "description": data.get("description", ""),
            "source": "builtin",
        })

    skins_path = _skins_dir()
    if skins_path.is_dir():
        for f in sorted(skins_path.glob("*.yaml")):
            data = _load_skin_from_yaml(f)
            if data:
                skin_name = data.get("name", f.stem)
                # Skip if it shadows a built-in
                if any(s["name"] == skin_name for s in result):
                    continue
                result.append({
                    "name": skin_name,
                    "description": data.get("description", ""),
                    "source": "user",
                })

    return result


def load_skin(name: str) -> SkinConfig:
    """Load a skin by name. Checks user skins first, then built-in."""
    # Check user skins directory
    skins_path = _skins_dir()
    user_file = skins_path / f"{name}.yaml"
    if user_file.is_file():
        data = _load_skin_from_yaml(user_file)
        if data:
            return _build_skin_config(data)

    # Check built-in skins
    if name in _BUILTIN_SKINS:
        return _build_skin_config(_BUILTIN_SKINS[name])

    # Fallback to default
    logger.warning("Skin '%s' not found, using default", name)
    return _build_skin_config(_BUILTIN_SKINS["default"])


def get_active_skin() -> SkinConfig:
    """Get the currently active skin config (cached)."""
    global _active_skin
    if _active_skin is None:
        _active_skin = load_skin(_active_skin_name)
    return _active_skin


def set_active_skin(name: str) -> SkinConfig:
    """Switch the active skin. Returns the new SkinConfig."""
    global _active_skin, _active_skin_name
    _active_skin_name = name
    _active_skin = load_skin(name)
    return _active_skin


def get_active_skin_name() -> str:
    """Get the name of the currently active skin."""
    return _active_skin_name


def init_skin_from_config(config: dict) -> None:
    """Initialize the active skin from CLI config at startup.

    Call this once during CLI init with the loaded config dict.
    """
    display = config.get("display", {})
    skin_name = display.get("skin", "default")
    if isinstance(skin_name, str) and skin_name.strip():
        set_active_skin(skin_name.strip())
    else:
        set_active_skin("default")