src/constants.py

"""
constants.py

This module defines global constants used throughout the project.
"""

# Standard Library Imports
from typing import Dict, List

# Third-Party Library Imports
from src.custom_types import (
    ComparisonType,
    OptionKey,
    OptionLabel,
    TTSProviderName,
)

CLIENT_ERROR_CODE = 400
SERVER_ERROR_CODE = 500
RATE_LIMIT_ERROR_CODE = 429


# UI constants
HUME_AI: TTSProviderName = "Hume AI"
ELEVENLABS: TTSProviderName = "ElevenLabs"
OPENAI: TTSProviderName = "OpenAI"

TTS_PROVIDERS: List[TTSProviderName] = ["Hume AI", "OpenAI", "ElevenLabs"]
TTS_PROVIDER_LINKS = {
    "Hume AI": {
        "provider_link": "https://hume.ai/",
        "model_link": "https://www.hume.ai/blog/octave-the-first-text-to-speech-model-that-understands-what-its-saying"
    },
    "ElevenLabs": {
        "provider_link": "https://elevenlabs.io/",
        "model_link": "https://elevenlabs.io/blog/rvg",
    },
    "OpenAI": {
        "provider_link": "https://openai.com/",
        "model_link": "https://platform.openai.com/docs/models/gpt-4o-mini-tts",
    }
}

HUME_TO_HUME: ComparisonType = "Hume AI - Hume AI"
HUME_TO_ELEVENLABS: ComparisonType = "Hume AI - ElevenLabs"
HUME_TO_OPENAI: ComparisonType = "Hume AI - OpenAI"
OPENAI_TO_ELEVENLABS: ComparisonType = "OpenAI - ElevenLabs"

CHARACTER_DESCRIPTION_MIN_LENGTH: int = 20
CHARACTER_DESCRIPTION_MAX_LENGTH: int = 400

TEXT_MIN_LENGTH: int = 100
TEXT_MAX_LENGTH: int = 400

OPTION_A_KEY: OptionKey = "option_a"
OPTION_B_KEY: OptionKey = "option_b"
OPTION_A_LABEL: OptionLabel = "Option A"
OPTION_B_LABEL: OptionLabel = "Option B"

SELECT_OPTION_A: str = "Select Option A"
SELECT_OPTION_B: str = "Select Option B"

GENERIC_API_ERROR_MESSAGE: str = "An unexpected error occurred while processing your request. Please try again shortly."

# A collection of pre-defined character descriptions categorized by theme, used to provide users with
# inspiration for generating creative, expressive text inputs for TTS, and generating novel voices.
SAMPLE_CHARACTER_DESCRIPTIONS: dict = {
    "🦘 Australian Naturalist": (
        "The speaker has a contagiously enthusiastic Australian accent, with the relaxed, sun-kissed vibe of a "
        "wildlife expert fresh off the outback, delivering an amazing, laid-back narration."
    ),
    "🧘 Meditation Guru": (
        "A mindfulness instructor with a gentle, soothing voice that flows at a slow, measured pace with natural "
        "pauses. Their consistently calm, low-pitched tone has minimal variation, creating a peaceful auditory "
        "experience."
    ),
    "🎬 Noir Detective": (
        "A 1940s private investigator narrating with a gravelly voice and deliberate pacing. "
        "Speaks with a cynical, world-weary tone that drops lower when delivering key observations."
    ),
    "🕯️ Victorian Ghost Storyteller": (
        "The speaker is a Victorian-era raconteur speaking with a refined English accent and formal, precise diction. Voice "
        "modulates between hushed, tense whispers and dramatic declarations when describing eerie occurrences."
    ),
    "🌿 English Naturalist": (
        "Speaker is a wildlife documentarian speaking with a crisp, articulate English accent and clear enunciation. Voice "
        "alternates between hushed, excited whispers and enthusiastic explanations filled with genuine wonder."
    ),
    "🌟 Texan Storyteller": (
        "A speaker from rural Texas speaking with a warm voice and distinctive Southern drawl featuring elongated "
        "vowels. Talks unhurriedly with a musical quality and occasional soft laughter."
    ),
    "🏄 Chill Surfer": (
        "The speaker is a California surfer talking with a casual, slightly nasal voice and laid-back rhythm. Uses rising "
        "inflections at sentence ends and bursts into spontaneous laughter when excited."
    ),
    "📢 Old-School Radio Announcer": (
        "The speaker has the voice of a seasoned horse race announcer, with a booming, energetic voice, a touch of "
        "old-school radio charm, and the enthusiastic delivery of a viral commentator."
    ),
    "👑 Obnoxious Royal": (
        "Speaker is a member of the English royal family speaks in a smug and authoritative voice in an obnoxious, proper "
        "English accent. They are insecure, arrogant, and prone to tantrums."
    ),
    "🏰 Medieval Peasant": (
        "A film portrayal of a medieval peasant speaking with a thick cockney accent and a worn voice, "
        "dripping with sarcasm and self-effacing humor."
    ),
}


# HTML and social media metadata for the Gradio application
# These tags define SEO-friendly content and provide rich previews when shared on social platforms
META_TAGS: List[Dict[str, str]] = [
    # HTML Meta Tags (description)
    {
        'name': 'description',
        'content': 'An open-source web application for comparing and evaluating the expressiveness of different text-to-speech models, including Hume AI and ElevenLabs.'
    },
    # Facebook Meta Tags
    {
        'property': 'og:url',
        'content': 'https://hume.ai'
    },
    {
        'property': 'og:type',
        'content': 'website'
    },
    {
        'property': 'og:title',
        'content': 'Expressive TTS Arena'
    },
    {
        'property': 'og:description',
        'content': 'An open-source web application for comparing and evaluating the expressiveness of different text-to-speech models, including Hume AI and ElevenLabs.'
    },
    {
        'property': 'og:image',
        'content': '/static/arena-opengraph-logo.png'
    },
    # Twitter Meta Tags
    {
        'name': 'twitter:card',
        'content': 'summary_large_image'
    },
    {
        'property': 'twitter:domain',
        'content': 'hume.ai'
    },
    {
        'property': 'twitter:url',
        'content': 'https://hume.ai'
    },
    {
        'name': 'twitter:creator',
        'content': '@hume_ai'
    },
    {
        'name': 'twitter:title',
        'content': 'Expressive TTS Arena'
    },
    {
        'name': 'twitter:description',
        'content': 'An open-source web application for comparing and evaluating the expressiveness of different text-to-speech models, including Hume AI and ElevenLabs.'
    },
    {
        'name': 'twitter:image',
        'content': '/static/arena-opengraph-logo.png'
    }
]