import os
import gspread
from pathlib import Path
from pydantic import BaseModel
from google.oauth2.service_account import Credentials
from config import prompt_settings
from app.utils.logger import get_logger
from app.utils.prompts.schemas import *
from functools import lru_cache

logger = get_logger("prompt")

_SCOPES = [
    "https://www.googleapis.com/auth/spreadsheets.readonly"
]

_sheet_cache: dict[str, tuple[str, str]] = {}


def _read_sheet_data(sheet_name: str) -> tuple[str, str]:
    if sheet_name not in _sheet_cache:
        creds = Credentials.from_service_account_file(
            prompt_settings.GOOGLE_SERVICE_ACCOUNT_JSON, scopes=_SCOPES
        )
        gc = gspread.authorize(creds)
        ws = gc.open_by_key(prompt_settings.PROMPT_SPREADSHEET).worksheet(sheet_name)
        _sheet_cache[sheet_name] = (ws.cell(3, 2).value, ws.cell(2, 2).value)
    return _sheet_cache[sheet_name]


class Prompt():
    sheet_name: str
    prompt_template: str
    prompt_model: str

    prompt_input_class = BaseModel
    prompt_output_class = BaseModel

    def __init__(self, sheet_name, prompt_input_class, prompt_output_class, template_file: str = None, prompt_model: str = None):
        self.sheet_name = sheet_name
        self.prompt_input_class = prompt_input_class
        self.prompt_output_class = prompt_output_class
        if template_file:
            self.prompt_template = Path(template_file).read_text(encoding="utf-8")
            self.prompt_model = prompt_model
            self._template_file = template_file
        else:
            self.prompt_template, self.prompt_model = _read_sheet_data(sheet_name)
            self._template_file = None

    def _reload_prompt(self):
        if self._template_file:
            self.prompt_template = Path(self._template_file).read_text(encoding="utf-8")
        else:
            _sheet_cache.pop(self.sheet_name, None)
            self.prompt_template, self.prompt_model = _read_sheet_data(self.sheet_name)

    def build_prompt(self, input_data:dict, silent:bool = False) -> str:
        verified_input = self.prompt_input_class(**input_data)
        build_template = self.prompt_template
        build_template = build_template.format(**verified_input.model_dump())
        if not silent:
            logger.debug(f"build_template: {build_template}")
            logger.debug(f"input_data: {input_data}")
        return build_template

marketing_prompt = Prompt(
    sheet_name="marketing",
    prompt_input_class=MarketingPromptInput,
    prompt_output_class=MarketingPromptOutput,
)

lyric_prompt = Prompt(
    sheet_name="lyric",
    prompt_input_class=LyricPromptInput,
    prompt_output_class=LyricPromptOutput,
)

yt_upload_prompt = Prompt(
    sheet_name="yt_upload",
    prompt_input_class=YTUploadPromptInput,
    prompt_output_class=YTUploadPromptOutput,
)

image_autotag_prompt = Prompt(
    sheet_name="image_tag",
    prompt_input_class=ImageTagPromptInput,
    prompt_output_class=ImageTagPromptOutput,
)

_SUBTITLE_TEMPLATE_PATH = str(Path(__file__).parent / "templates" / "subtitle_prompt.txt")


@lru_cache()
def create_dynamic_subtitle_prompt(length: int) -> Prompt:
    return Prompt(
        sheet_name="subtitle",
        prompt_input_class=SubtitlePromptInput,
        prompt_output_class=SubtitlePromptOutput[length],
        template_file=_SUBTITLE_TEMPLATE_PATH,
        prompt_model=os.getenv("SUBTITLE_PROMPT_MODEL", "gpt-4o-mini"),
    )


def reload_all_prompt():
    marketing_prompt._reload_prompt()
    lyric_prompt._reload_prompt()
    yt_upload_prompt._reload_prompt()
    image_autotag_prompt._reload_prompt()