import pandas as pd
from typing import Tuple
from concurrent.futures import ThreadPoolExecutor, as_completed

from .jobs import JobType, Location
from .scrapers.indeed import IndeedScraper
from .scrapers.ziprecruiter import ZipRecruiterScraper
from .scrapers.glassdoor import GlassdoorScraper
from .scrapers.linkedin import LinkedInScraper
from .scrapers import ScraperInput, Site, JobResponse, Country
from .scrapers.exceptions import (
    LinkedInException,
    IndeedException,
    ZipRecruiterException,
    GlassdoorException,
)


def scrape_jobs(
    site_name: str | list[str] | Site | list[Site] | None = None,
    search_term: str | None = None,
    location: str | None = None,
    distance: int | None = None,
    is_remote: bool = False,
    job_type: str | None = None,
    easy_apply: bool | None = None,
    results_wanted: int = 15,
    country_indeed: str = "usa",
    hyperlinks: bool = False,
    proxy: str | None = None,
    description_format: str = "markdown",
    linkedin_fetch_description: bool | None = False,
    linkedin_company_ids: list[int] | None = None,
    offset: int | None = 0,
    hours_old: int = None,
    **kwargs,
) -> pd.DataFrame:
    """
    Simultaneously scrapes job data from multiple job sites.
    :return: results_wanted: pandas dataframe containing job data
    """
    SCRAPER_MAPPING = {
        Site.LINKEDIN: LinkedInScraper,
        Site.INDEED: IndeedScraper,
        Site.ZIP_RECRUITER: ZipRecruiterScraper,
        Site.GLASSDOOR: GlassdoorScraper,
    }

    def map_str_to_site(site_name: str) -> Site:
        return Site[site_name.upper()]

    def get_enum_from_value(value_str):
        for job_type in JobType:
            if value_str in job_type.value:
                return job_type
        raise Exception(f"Invalid job type: {value_str}")

    job_type = get_enum_from_value(job_type) if job_type else None

    def get_site_type():
        site_types = list(Site)
        if isinstance(site_name, str):
            site_types = [map_str_to_site(site_name)]
        elif isinstance(site_name, Site):
            site_types = [site_name]
        elif isinstance(site_name, list):
            site_types = [
                map_str_to_site(site) if isinstance(site, str) else site
                for site in site_name
            ]
        return site_types
    country_enum = Country.from_string(country_indeed)

    scraper_input = ScraperInput(
        site_type=get_site_type(),
        country=country_enum,
        search_term=search_term,
        location=location,
        distance=distance,
        is_remote=is_remote,
        job_type=job_type,
        easy_apply=easy_apply,
        description_format=description_format,
        linkedin_fetch_description=linkedin_fetch_description,
        results_wanted=results_wanted,
        linkedin_company_ids=linkedin_company_ids,
        offset=offset,
        hours_old=hours_old
    )

    def scrape_site(site: Site) -> Tuple[str, JobResponse]:
        scraper_class = SCRAPER_MAPPING[site]
        scraper = scraper_class(proxy=proxy)
        scraped_data: JobResponse = scraper.scrape(scraper_input)
        return site.value, scraped_data

    site_to_jobs_dict = {}

    def worker(site):
        site_val, scraped_info = scrape_site(site)
        return site_val, scraped_info

    with ThreadPoolExecutor() as executor:
        future_to_site = {
            executor.submit(worker, site): site for site in scraper_input.site_type
        }

        for future in as_completed(future_to_site):
            site_value, scraped_data = future.result()
            site_to_jobs_dict[site_value] = scraped_data

    jobs_dfs: list[pd.DataFrame] = []

    for site, job_response in site_to_jobs_dict.items():
        for job in job_response.jobs:
            job_data = job.dict()
            job_data[
                "job_url_hyper"
            ] = f'<a href="{job_data["job_url"]}">{job_data["job_url"]}</a>'
            job_data["site"] = site
            job_data["company"] = job_data["company_name"]
            job_data["job_type"] = (
                ", ".join(job_type.value[0] for job_type in job_data["job_type"])
                if job_data["job_type"]
                else None
            )
            job_data["emails"] = (
                ", ".join(job_data["emails"]) if job_data["emails"] else None
            )
            if job_data["location"]:
                job_data["location"] = Location(
                    **job_data["location"]
                ).display_location()

            compensation_obj = job_data.get("compensation")
            if compensation_obj and isinstance(compensation_obj, dict):
                job_data["interval"] = (
                    compensation_obj.get("interval").value
                    if compensation_obj.get("interval")
                    else None
                )
                job_data["min_amount"] = compensation_obj.get("min_amount")
                job_data["max_amount"] = compensation_obj.get("max_amount")
                job_data["currency"] = compensation_obj.get("currency", "USD")
            else:
                job_data["interval"] = None
                job_data["min_amount"] = None
                job_data["max_amount"] = None
                job_data["currency"] = None

            job_df = pd.DataFrame([job_data])
            jobs_dfs.append(job_df)

    if jobs_dfs:
        # Step 1: Filter out all-NA columns from each DataFrame before concatenation
        filtered_dfs = [df.dropna(axis=1, how='all') for df in jobs_dfs]
        
        # Step 2: Concatenate the filtered DataFrames
        jobs_df = pd.concat(filtered_dfs, ignore_index=True)
        
        # Desired column order
        desired_order = [
            "job_url_hyper" if hyperlinks else "job_url",
            "site",
            "title",
            "company",
            "company_url",
            "location",
            "job_type",
            "date_posted",
            "interval",
            "min_amount",
            "max_amount",
            "currency",
            "is_remote",
            "num_urgent_words",
            "benefits",
            "emails",
            "description",
        ]
        
        # Step 3: Ensure all desired columns are present, adding missing ones as empty
        for column in desired_order:
            if column not in jobs_df.columns:
                jobs_df[column] = None  # Add missing columns as empty
        
        # Reorder the DataFrame according to the desired order
        jobs_df = jobs_df[desired_order]
        
        # Step 4: Sort the DataFrame as required
        return jobs_df.sort_values(by=['site', 'date_posted'], ascending=[True, False])
    else:
        return pd.DataFrame()