import os
import random
from datetime import datetime, timedelta
from typing import Union
import pathlib
import smtplib
from email.message import EmailMessage
import streamlit as st
from sqlalchemy.orm import Session
from sqlalchemy import select

from models import Employee, Job , JobsApplied,User, ENGINE
from llm import parse, rerank



st.markdown("""-
   <style>
    
    .stButton > button{
    border: black;    
    box-shadow: 0 12px 16px 0 rgba(0,0,0,0.24), 0 17px 50px 0 rgba(0,0,0,0.19);
    }
</style>""",unsafe_allow_html=True)

def clear_cache():
    for k in st.session_state:
        del st.session_state[k]

def login() -> Union[Employee,None]:
    login_container = st.empty()
    with login_container.container():
        employee_id = st.text_input(label=":email: User ID", placeholder = "User ID").upper().strip()
        password = st.text_input(label = ":lock: Password", placeholder = "Password", type = "password")
        button = st.button('Login', type = "secondary")

        if button:
            if employee_id and password:
                with Session(ENGINE) as session:
                    stmt = select(Employee).where(Employee.employee_id == employee_id).\
                        where(Employee.password == password)
                    employee = session.scalars(stmt).one_or_none()
                    print(employee)
                    
                if employee is None:
                    st.error('Invalid UserID/password')
                    return
                
                st.session_state['employee_logged'] = True
                st.session_state['employee'] = employee
                login_container.empty()
                
                return employee
            else:
                st.error('Empty UserID/Password')


def add_to_db(**job) -> None:
    
    job_id = ''.join(chr(random.randint(65,90)) for i in range(5))+f'{random.randint(100,1000)}'
    job['job_id'] = job_id
    job['employee_id'] = st.session_state["employee"].employee_id
    job['created_at'] = datetime.now().strftime("%d-%m-%Y %H:%M:%S")
    job['primary_skills'] = ', '.join(job['primary_skills'])
    job['secondary_skills'] = ', '.join(job['secondary_skills'])
    
    
    with Session(ENGINE) as session:
        job_object = Job(**job)
        session.add_all([job_object])
        session.commit()
        st.success(f"Successfully posted job {job['post_name']}!")


def add_job() -> None:
    post_name = st.text_input(label = 'Post Name').strip().title()
    description = st.text_area(label = 'Job Description').strip()
    responsibilities = st.text_area(label = "Responsibility").strip()
    vacancies = st.number_input(label="Number Vacancies",min_value=1)
    col1, col2 = st.columns(2)
    with col1:
        min_experience = st.number_input(label = "Minimum Experience",min_value = 0, )
    with col2:
        max_experience = st.number_input(label = "Maximum Experience",min_value = 1, )
    number_of_primary_skills = st.number_input(label = "How many primary skills?",min_value = 1, )
    primary_skills = [st.text_input(label = f'Primary Skill {i}',key=f'Primary Skill {i}').strip() for i in range(1,number_of_primary_skills+1)]
    number_of_secondary_skills = st.number_input(label = "How many secondary skills?",min_value = 0, )
    secondary_skills = [st.text_input(label = f'Secondary Skill {i}',key=f'Secondary Skill {i}').strip() for i in range(1,number_of_secondary_skills+1)]
    st.markdown("Expires at")
    col1, col2 = st.columns(2)
    with col1:
        expires_date = st.date_input(label = "expries date",value =datetime.now() + timedelta(days = 1), min_value = datetime.now() + timedelta(days = 1), max_value=None, label_visibility="collapsed")
        print(expires_date )
    with col2:
        expires_time = st.time_input(label = "Time Input", label_visibility="collapsed")
        print(expires_time)
    expires_at = f'{expires_date.strftime("%d-%m-%Y")} {expires_time.strftime("%H:%M:%S")}'
    st.markdown("<p style='color: red'>⚠️ Check before you submit once submitted you cannot make changes</p>", unsafe_allow_html=True)
    if st.button("Post"):
        if (post_name and description and responsibilities and primary_skills):
            if min_experience <= max_experience:
                job = {
                    "post_name" : post_name, 'description': description,'min_experience': min_experience,'max_experience': max_experience,
                    'primary_skills': primary_skills, 'secondary_skills': secondary_skills,'responsibilities':responsibilities,
                    'expires_at': expires_at, 'vacancies': vacancies

                }
            

                add_to_db(**job)
                return True
            st.error("Minimum Experience must be less than maximum experience")
            return
        st.error("Post Name/Description/Responsibility/Primary SKills are required")
    
           

def post_job():
    st.session_state['employee']
    st.session_state['employee_logged']
    if st.session_state['employee_logged']:
        col1, col2 = st.columns([0.001, 0.01])
        with col2:
            st.markdown(f'Would you like to include a job vacancy listing. {st.session_state["employee"].full_name}?')
        with col1:
            if st.button(':heavy_plus_sign:'):
                st.session_state['add_job'] = True
        
        if st.session_state['add_job']:
            add_job_container = st.empty()
            with add_job_container.container():
                is_job_posted = add_job()
            if is_job_posted:
                add_job_container.empty()
        

def  get_jobs_posted() -> None:
    with Session(ENGINE) as session:
        stmt = select(Job).where(Job.employee_id == st.session_state["employee"].employee_id)
        jobs = session.scalars(stmt).all()
    print(jobs)
    for job in jobs:
        with st.expander(f"{job.job_id}: {job.post_name} posted at: {job.created_at}"):
            pass
    


def get_users_who_applied_for_jobs():
    
    #Get Jobs Posted
    with Session(ENGINE) as session:
        stmt = select(Job).where(Job.employee_id == st.session_state["employee"].employee_id)
        jobs = session.scalars(stmt).all()
    
    if not jobs:
        st.info("No jobs posted!")
        return
    
    job_id = st.selectbox("Filter by job_id",options=[job.job_id for job in jobs])
    

    
    with Session(ENGINE) as session:
        stmt = select(JobsApplied).where(JobsApplied.job_id == job_id)
        users_applied_for_jobs = session.scalars(stmt).all()
        
        if not users_applied_for_jobs:
            st.info('No users have applied for job')
            return False
        
        re_rank_resumes_container = st.empty()
        with re_rank_resumes_container.container():
            st.markdown("""<p style="font-family:Garamond;text-indent: 45vh;font-size:25px">Jobs Application Details</p>""",unsafe_allow_html=True)
            col1, col2 = st.columns([0.001, 0.01])
            with col1:
                round_number = users_applied_for_jobs[0].round_number 
                st.markdown(f"""<p style="font-size:20px"><span style = "font-family:Garamond;">Round</span><span style="font-family:monospace;padding: 10px 20px">{round_number}</span></p>""", unsafe_allow_html=True)
            with col2:
                num_docs = st.number_input(label="Top Resumes",min_value=1, max_value=len(users_applied_for_jobs))
            for jobs_application in users_applied_for_jobs:
                st.markdown(f"""<p style="border: 2px solid black;padding: 10px 20px; box-shadow: 10px 10px 5px #aaaaaa"><span style="font-family:Garamond;">User Email ID</span>: <span style="font-family:monospace">{jobs_application.email_id}</span><br><span style="font-family:Garamond">Current Rank: <span style="font-family:monospace">{jobs_application.rank}</span></p>""",unsafe_allow_html=True)
            col1,col2, col3 = st.columns(3)
            with col2:
                if st.button("Rank Resumes"):
                    st.session_state['rank_resumes'] = True
        
        #Ranking Resumes
        if st.session_state['rank_resumes']:
            re_rank_resumes_container.empty()
            docs = get_docs(users_applied_for_jobs,job_id)
            re_ranked = rerank(job_id,docs,num_docs)
            candidates = [r.document['text'].split('-'*50)[0].strip() for r in re_ranked.results]
            st.markdown(f"<p style='font-family:Garamond;text-indent: 45vh;font-size:25px'>Resumes re-ranked:</p>",unsafe_allow_html=True)
            for candidate in candidates:
                st.markdown(f"""<p style="border: 2px solid black;padding: 10px 20px; box-shadow: 10px 10px 5px #aaaaaa"><span style="font-family:Garamond;">User Email ID</span>: <span style="font-family:monospace">{candidate}</span></p>""",unsafe_allow_html=True)
            col1,col2, col3 = st.columns(3)
            with col2:
                if st.button("Send Emails"):
                    st.session_state['send_resumes']  = True
            if  st.session_state['send_resumes']:
                    add_job_aplication_details(job_id,round_number,candidates)
        
            
def add_job_aplication_details(job_id,round_number,candidates):
    def update(job_application):
        print('----------------------------------------4')
        job_application.round_number += 1
        job_application.rank = job_application.round_number
        return job_application
   
    

    with Session(ENGINE) as session:
        stmt =  select(JobsApplied).where(JobsApplied.job_id == job_id).where(JobsApplied.email_id.not_in(candidates))
        jobs = session.scalars(stmt).all()
        for job in jobs: 
            session.delete(job)
        session.commit()
        print('deleted')
    with Session(ENGINE) as session:
        stmt =  select(JobsApplied).where(JobsApplied.job_id == job_id).where(JobsApplied.email_id.in_(candidates))
        jobs = session.scalars(stmt).all()
        for job in jobs: 
            update(job)
        session.commit()
        print('updated')
    sending_emails(job_id, candidates)
        
def sending_emails(job_id, candidates):
    email_message = EmailMessage()
    email_message['From'] = st.session_state['employee'].email_id
    email_message['To'] = candidates
    email_message['Subject'] = f'You are selected for Job ID: {job_id}.'
    email_message.set_content('Hello,\nYou are selected to attend the interview. Please login to your profile and attend.')
    with smtplib.SMTP_SSL('smtp.gmail.com',465) as smtp:
        # st.write(os.environ['EMAIL'])
        smtp.login(st.session_state['employee'].email_id, os.environ['EMAIL'])
        smtp.send_message(email_message)
    st.success(f'⚠️Email Sent SUccessfully')

        

            
def get_docs(jobs_applications,job_id):
    docs = []
    print(f'resumes/{job_id}')
    resumes_dir = pathlib.Path(f'resumes/{job_id}')
    

    for resume in resumes_dir.iterdir():
        print(resume)
        parsed_text = parse(resume)
        print(parsed_text)
        print('---------------------------------------------------------------------------')
        email_id = resume.stem.split('-')[0]
        text = f"{email_id}"+'-'*50+parsed_text
        docs.append(text)
    return docs
    
        




        



print('Before settings')

# Setting Session states
if 'employee_logged' not in st.session_state:
    st.session_state['employee_logged'] = False
if 'employee' not in st.session_state:
    st.session_state['employee'] = None
if 'add_job' not in st.session_state:
    st.session_state['add_job'] = False

if 'add_new_skill' not in st.session_state:
    st.session_state['add_new_skill'] = False

if 'rank_resumes' not in st.session_state:
    st.session_state['rank_resumes'] = False

if 'rank_resumes' not in st.session_state:
    st.session_state['rank_resumes'] = False

if 'send_resumes' not in st.session_state:
    st.session_state['send_resumes'] = False











print('script start')

#Login


if not st.session_state['employee_logged']:
    employee = login()


if st.session_state['employee_logged']:
    col1, col2 = st.columns(2)
    with col2:
        st.button('Log Out',on_click=clear_cache)
            

    tab1, tab2, tab3 = st.tabs(["Post Jobs","Jobs Posted","Get Job Applied Details"])
    with tab1:
        post_job()
    with tab2:
        get_jobs_posted()
    with tab3:
        get_users_who_applied_for_jobs()