#!/bin/bash
#
# File: .claude/hooks/play-tts-piper.sh
#
# AgentVibes - Finally, your AI Agents can Talk Back! Text-to-Speech WITH personality for AI Assistants!
# Website: https://agentvibes.org
# Repository: https://github.com/paulpreibisch/AgentVibes
#
# Co-created by Paul Preibisch with Claude AI
# Copyright (c) 2025 Paul Preibisch
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# DISCLAIMER: This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
# express or implied. Use at your own risk. See the Apache License for details.
#
# ---
#
# @fileoverview Piper TTS Provider Implementation - Free, offline neural TTS
# @context Provides local, privacy-first TTS alternative to cloud services for WSL/Linux
# @architecture Implements provider interface contract for Piper binary integration
# @dependencies piper (pipx), piper-voice-manager.sh, mpv/aplay, ffmpeg (optional padding)
# @entrypoints Called by play-tts.sh router when provider=piper
# @patterns Provider contract: text/voice → audio file path, voice auto-download, language-aware synthesis
# @related play-tts.sh, piper-voice-manager.sh, language-manager.sh, GitHub Issue #25
#

# Fix locale warnings
export LC_ALL=C

TEXT="$1"
VOICE_OVERRIDE="$2"  # Optional: voice model name

# Source voice manager and language manager
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/piper-voice-manager.sh"
source "$SCRIPT_DIR/language-manager.sh"

# Default voice for Piper
DEFAULT_VOICE="en_US-lessac-medium"

# @function determine_voice_model
# @intent Resolve voice name to Piper model name with language support
# @why Support voice override, language-specific voices, and default fallback
# @param Uses global: $VOICE_OVERRIDE
# @returns Sets $VOICE_MODEL global variable
# @sideeffects None
VOICE_MODEL=""

# Get current language setting
CURRENT_LANGUAGE=$(get_language_code)

if [[ -n "$VOICE_OVERRIDE" ]]; then
  # Use override if provided
  VOICE_MODEL="$VOICE_OVERRIDE"
  echo "🎤 Using voice: $VOICE_OVERRIDE (session-specific)"
else
  # Try to get voice from voice file (check CLAUDE_PROJECT_DIR first for MCP context)
  VOICE_FILE=""

  # Priority order:
  # 1. CLAUDE_PROJECT_DIR env var (set by MCP for project-specific settings)
  # 2. Script location (for direct slash command usage)
  # 3. Global ~/.claude (fallback)

  if [[ -n "$CLAUDE_PROJECT_DIR" ]] && [[ -f "$CLAUDE_PROJECT_DIR/.claude/tts-voice.txt" ]]; then
    # MCP context: Use the project directory where MCP was invoked
    VOICE_FILE="$CLAUDE_PROJECT_DIR/.claude/tts-voice.txt"
  elif [[ -f "$SCRIPT_DIR/../tts-voice.txt" ]]; then
    # Direct usage: Use script location
    VOICE_FILE="$SCRIPT_DIR/../tts-voice.txt"
  elif [[ -f "$HOME/.claude/tts-voice.txt" ]]; then
    # Fallback: Use global
    VOICE_FILE="$HOME/.claude/tts-voice.txt"
  fi

  if [[ -n "$VOICE_FILE" ]]; then
    FILE_VOICE=$(cat "$VOICE_FILE" 2>/dev/null)

    # Check for multi-speaker voice (model + speaker ID stored separately)
    # Use same directory as VOICE_FILE for consistency
    VOICE_DIR=$(dirname "$VOICE_FILE")
    MODEL_FILE="$VOICE_DIR/tts-piper-model.txt"
    SPEAKER_ID_FILE="$VOICE_DIR/tts-piper-speaker-id.txt"

    if [[ -f "$MODEL_FILE" ]] && [[ -f "$SPEAKER_ID_FILE" ]]; then
      # Multi-speaker voice
      VOICE_MODEL=$(cat "$MODEL_FILE" 2>/dev/null)
      SPEAKER_ID=$(cat "$SPEAKER_ID_FILE" 2>/dev/null)
      echo "🎭 Using multi-speaker voice: $FILE_VOICE (Model: $VOICE_MODEL, Speaker ID: $SPEAKER_ID)"
    # Check if it's a standard Piper model name or custom voice (just use as-is)
    elif [[ -n "$FILE_VOICE" ]]; then
      VOICE_MODEL="$FILE_VOICE"
    fi
  fi

  # If no Piper voice from file, try language-specific voice
  if [[ -z "$VOICE_MODEL" ]]; then
    LANG_VOICE=$(get_voice_for_language "$CURRENT_LANGUAGE" "piper" 2>/dev/null)

    if [[ -n "$LANG_VOICE" ]]; then
      VOICE_MODEL="$LANG_VOICE"
      echo "🌍 Using $CURRENT_LANGUAGE voice: $LANG_VOICE (Piper)"
    else
      # Use default voice
      VOICE_MODEL="$DEFAULT_VOICE"
    fi
  fi
fi

# @function validate_inputs
# @intent Check required parameters
# @why Fail fast with clear errors if inputs missing
# @exitcode 1=missing text, 2=missing piper binary
if [[ -z "$TEXT" ]]; then
  echo "Usage: $0 \"text to speak\" [voice_model_name]"
  exit 1
fi

# Check if Piper is installed
if ! command -v piper &> /dev/null; then
  echo "❌ Error: Piper TTS not installed"
  echo "Install with: pipx install piper-tts"
  echo "Or run: .claude/hooks/piper-installer.sh"
  exit 2
fi

# @function ensure_voice_downloaded
# @intent Download voice model if not cached
# @why Provide seamless experience with automatic downloads
# @param Uses global: $VOICE_MODEL
# @sideeffects Downloads voice model files
# @edgecases Prompts user for consent before downloading
if ! verify_voice "$VOICE_MODEL"; then
  echo "📥 Voice model not found: $VOICE_MODEL"
  echo "   File size: ~25MB"
  echo "   Preview: https://huggingface.co/rhasspy/piper-voices"
  echo ""
  read -p "   Download this voice model? [y/N]: " -n 1 -r
  echo

  if [[ $REPLY =~ ^[Yy]$ ]]; then
    if ! download_voice "$VOICE_MODEL"; then
      echo "❌ Failed to download voice model"
      echo "Fix: Download manually or choose different voice"
      exit 3
    fi
  else
    echo "❌ Voice download cancelled"
    exit 3
  fi
fi

# Get voice model path
VOICE_PATH=$(get_voice_path "$VOICE_MODEL")
if [[ $? -ne 0 ]]; then
  echo "❌ Voice model path not found: $VOICE_MODEL"
  exit 3
fi

# @function determine_audio_directory
# @intent Find appropriate directory for audio file storage
# @why Supports project-local and global storage
# @returns Sets $AUDIO_DIR global variable
if [[ -n "$CLAUDE_PROJECT_DIR" ]]; then
  AUDIO_DIR="$CLAUDE_PROJECT_DIR/.claude/audio"
else
  # Fallback: try to find .claude directory in current path
  CURRENT_DIR="$PWD"
  while [[ "$CURRENT_DIR" != "/" ]]; do
    if [[ -d "$CURRENT_DIR/.claude" ]]; then
      AUDIO_DIR="$CURRENT_DIR/.claude/audio"
      break
    fi
    CURRENT_DIR=$(dirname "$CURRENT_DIR")
  done
  # Final fallback to global if no project .claude found
  if [[ -z "$AUDIO_DIR" ]]; then
    AUDIO_DIR="$HOME/.claude/audio"
  fi
fi

mkdir -p "$AUDIO_DIR"
TEMP_FILE="$AUDIO_DIR/tts-$(date +%s).wav"

# @function get_speech_rate
# @intent Determine speech rate for Piper synthesis
# @why Convert user-facing speed (0.5=slower, 2.0=faster) to Piper length-scale (inverted)
# @returns Piper length-scale value (inverted from user scale)
# @note Piper uses length-scale where higher=slower, opposite of user expectation
get_speech_rate() {
  local target_config=""
  local main_config=""

  # Check for target-specific config first (new and legacy paths)
  if [[ -f "$SCRIPT_DIR/../config/tts-target-speech-rate.txt" ]]; then
    target_config="$SCRIPT_DIR/../config/tts-target-speech-rate.txt"
  elif [[ -f "$HOME/.claude/config/tts-target-speech-rate.txt" ]]; then
    target_config="$HOME/.claude/config/tts-target-speech-rate.txt"
  elif [[ -f "$SCRIPT_DIR/../config/piper-target-speech-rate.txt" ]]; then
    target_config="$SCRIPT_DIR/../config/piper-target-speech-rate.txt"
  elif [[ -f "$HOME/.claude/config/piper-target-speech-rate.txt" ]]; then
    target_config="$HOME/.claude/config/piper-target-speech-rate.txt"
  fi

  # Check for main config (new and legacy paths)
  if [[ -f "$SCRIPT_DIR/../config/tts-speech-rate.txt" ]]; then
    main_config="$SCRIPT_DIR/../config/tts-speech-rate.txt"
  elif [[ -f "$HOME/.claude/config/tts-speech-rate.txt" ]]; then
    main_config="$HOME/.claude/config/tts-speech-rate.txt"
  elif [[ -f "$SCRIPT_DIR/../config/piper-speech-rate.txt" ]]; then
    main_config="$SCRIPT_DIR/../config/piper-speech-rate.txt"
  elif [[ -f "$HOME/.claude/config/piper-speech-rate.txt" ]]; then
    main_config="$HOME/.claude/config/piper-speech-rate.txt"
  fi

  # If this is a non-English voice and target config exists, use it
  if [[ "$CURRENT_LANGUAGE" != "english" ]] && [[ -n "$target_config" ]]; then
    local user_speed=$(cat "$target_config" 2>/dev/null)
    # Convert user speed to Piper length-scale (invert)
    # User: 0.5=slower, 1.0=normal, 2.0=faster
    # Piper: 2.0=slower, 1.0=normal, 0.5=faster
    # Formula: piper_length_scale = 1.0 / user_speed
    echo "scale=2; 1.0 / $user_speed" | bc -l 2>/dev/null || echo "1.0"
    return
  fi

  # Otherwise use main config if available
  if [[ -n "$main_config" ]]; then
    local user_speed=$(grep -v '^#' "$main_config" 2>/dev/null | grep -v '^$' | tail -1)
    echo "scale=2; 1.0 / $user_speed" | bc -l 2>/dev/null || echo "1.0"
    return
  fi

  # Default: 1.0 (normal) for English, 2.0 (slower) for learning
  if [[ "$CURRENT_LANGUAGE" != "english" ]]; then
    echo "2.0"
  else
    echo "1.0"
  fi
}

SPEECH_RATE=$(get_speech_rate)

# @function synthesize_with_piper
# @intent Generate speech using Piper TTS
# @why Provides free, offline TTS alternative
# @param Uses globals: $TEXT, $VOICE_PATH, $SPEECH_RATE, $SPEAKER_ID (optional)
# @returns Creates WAV file at $TEMP_FILE
# @exitcode 0=success, 4=synthesis error
# @sideeffects Creates audio file
# @edgecases Handles piper errors, invalid models, multi-speaker voices
if [[ -n "$SPEAKER_ID" ]]; then
  # Multi-speaker voice: Pass speaker ID
  echo "$TEXT" | piper --model "$VOICE_PATH" --speaker "$SPEAKER_ID" --length-scale "$SPEECH_RATE" --output_file "$TEMP_FILE" 2>/dev/null
else
  # Single-speaker voice
  echo "$TEXT" | piper --model "$VOICE_PATH" --length-scale "$SPEECH_RATE" --output_file "$TEMP_FILE" 2>/dev/null
fi

if [[ ! -f "$TEMP_FILE" ]] || [[ ! -s "$TEMP_FILE" ]]; then
  echo "❌ Failed to synthesize speech with Piper"
  echo "Voice model: $VOICE_MODEL"
  echo "Check that voice model is valid"
  exit 4
fi

# @function add_silence_padding
# @intent Add silence to prevent WSL audio static
# @why WSL audio subsystem cuts off first ~200ms
# @param Uses global: $TEMP_FILE
# @returns Updates $TEMP_FILE to padded version
# @sideeffects Modifies audio file
# AI NOTE: Use ffmpeg if available, otherwise skip padding (degraded experience)
if command -v ffmpeg &> /dev/null; then
  PADDED_FILE="$AUDIO_DIR/tts-padded-$(date +%s).wav"
  # Add 200ms of silence at the beginning
  ffmpeg -f lavfi -i anullsrc=r=44100:cl=stereo:d=0.2 -i "$TEMP_FILE" \
    -filter_complex "[0:a][1:a]concat=n=2:v=0:a=1[out]" \
    -map "[out]" -y "$PADDED_FILE" 2>/dev/null

  if [[ -f "$PADDED_FILE" ]]; then
    rm -f "$TEMP_FILE"
    TEMP_FILE="$PADDED_FILE"
  fi
fi

# @function play_audio
# @intent Play generated audio using available player with sequential playback
# @why Support multiple audio players and prevent overlapping audio in learning mode
# @param Uses global: $TEMP_FILE, $CURRENT_LANGUAGE
# @sideeffects Plays audio with lock mechanism for sequential playback
LOCK_FILE="/tmp/agentvibes-audio.lock"

# Wait for previous audio to finish (max 30 seconds)
for i in {1..60}; do
  if [ ! -f "$LOCK_FILE" ]; then
    break
  fi
  sleep 0.5
done

# Track last target language audio for replay command
if [[ "$CURRENT_LANGUAGE" != "english" ]]; then
  TARGET_AUDIO_FILE="${CLAUDE_PROJECT_DIR:-.}/.claude/last-target-audio.txt"
  echo "$TEMP_FILE" > "$TARGET_AUDIO_FILE"
fi

# Create lock and play audio
touch "$LOCK_FILE"

# Get audio duration for proper lock timing
DURATION=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$TEMP_FILE" 2>/dev/null)
DURATION=${DURATION%.*}  # Round to integer
DURATION=${DURATION:-1}   # Default to 1 second if detection fails

# Play audio in background (skip if in test mode)
if [[ "${AGENTVIBES_TEST_MODE:-false}" != "true" ]]; then
  (mpv "$TEMP_FILE" || aplay "$TEMP_FILE" || paplay "$TEMP_FILE") >/dev/null 2>&1 &
  PLAYER_PID=$!
fi

# Wait for audio to finish, then release lock
(sleep $DURATION; rm -f "$LOCK_FILE") &
disown

echo "🎵 Saved to: $TEMP_FILE"
echo "🎤 Voice used: $VOICE_MODEL (Piper TTS)"