import streamlit as st
import json
import tempfile
import pandas as pd
import altair as alt
from typing import Dict, Any, Optional

from roe_ai import generate_insights, extract_job_details, evaluate_candidate_job_fit


def __init__():
    """
    Initialize the Streamlit application with configuration and styling.
    """
    _configure_page()
    _apply_custom_css()


def _configure_page():
    """
    Set up the Streamlit page configuration.
    """
    st.set_page_config(
        page_title="Resume Intelligence",
        page_icon="📋",
        layout="wide",
        initial_sidebar_state="expanded",
    )


def _apply_custom_css():
    """
    Apply custom CSS styling to the Streamlit application.
    """
    st.markdown(
        """
    <style>
    .stButton>button {
        background-color: #4CAF50;
        border-color: white;
        color: white;
        transition: all 0.3s ease;
    }
    .stButton>button:hover {
        background-color: #45a049;
        transform: scale(1.05);
    }
    .skill-badge {
        display: inline-flex;
        align-items: center;
        background-color: #e1f5fe;
        color: #0277bd;
        padding: 5px 10px;
        border-radius: 20px;
        margin: 2px;
    }
    .skill-proficiency {
        margin-left: 5px;
        background-color: #4CAF50;
        color: white;
        border-radius: 10px;
        padding: 2px 6px;
        font-size: 0.8em;
    }
    .skill-gap {
        background-color:#fee6e6; 
        border-left: 4px solid red; 
        padding: 10px; 
        margin-bottom: 10px; 
        border-radius: 5px;
    }
    .strengths {
        background-color:#e6f3e6; 
        border-left: 4px solid green; 
        padding: 10px; 
        margin-bottom: 10px; 
        border-radius: 5px;
    }
    </style>
    """,
        unsafe_allow_html=True,
    )


def run():
    """
    Main method to run the Streamlit application.
    """
    _render_title()
    _configure_sidebar()

    uploaded_file = _upload_resume()

    if uploaded_file is not None:
        _process_resume(uploaded_file)


def _render_title():
    """
    Render the application title and description.
    """
    st.title("📄 Resume Intelligence Platform with Roe AI")
    st.write("Upload a PDF document to process with our AI agent.")


def _configure_sidebar():
    """
    Configure the sidebar with application settings.
    """
    st.sidebar.header("🔧 Configuration")

    default_instruction = (
        "Please extract actionable insights from the candidates resume"
    )

    st.session_state.insights_prompt = st.sidebar.text_area(
        "AI Agent Instruction", value=default_instruction, height=150, disabled=True
    )

    st.session_state.page_filter = st.sidebar.text_input(
        "Page Range to Process", value="@PAGERANGE(1-3)", disabled=True
    )


def _upload_resume():
    """
    Handle resume file upload.

    Returns:
        Uploaded file or None
    """
    return st.file_uploader(
        "Choose a PDF file",
        type="pdf",
        help="Upload a PDF document to process with the Roe AI agent",
    )


def _process_resume(uploaded_file):
    """
    Process the uploaded resume and display insights.

    Args:
        uploaded_file: Uploaded PDF file
    """
    if st.sidebar.button(
        "Extract Resume Insights",
        type="primary",
        disabled=hasattr(st.session_state, "insights"),
    ):
        insights = _extract_resume_insights(uploaded_file)
        st.session_state.insights = insights

    if hasattr(st.session_state, "insights"):
        _display_candidate_profile(st.session_state.insights)
        _setup_job_description_section(st.session_state.insights)

    if (
        hasattr(st.session_state, "show_scroll_message")
        and st.session_state.show_scroll_message
    ):
        st.sidebar.info("Please scroll down to see results")


def _extract_resume_insights(uploaded_file):
    """
    Extract insights from the uploaded resume.

    Args:
        uploaded_file: Uploaded PDF file

    Returns:
        Extracted insights or None
    """
    with st.spinner("Analyzing resume..."):
        with tempfile.NamedTemporaryFile(delete=False, suffix=".pdf") as temp_file:
            temp_file.write(uploaded_file.getvalue())
            temp_file_path = temp_file.name

            result = generate_insights(
                temp_file_path,
                st.session_state.insights_prompt,
                st.session_state.page_filter,
            )

            insights = json.loads(result[0]["value"])

            # Validate insights against expected schema
            required_fields = ["name", "email", "skills"]
            if all(field in insights for field in required_fields):
                # st.success("Resume processed successfully!")
                return insights

            st.warning("Received response does not match expected schema.")
            return None


def _setup_job_description_section(insights):
    """
    Set up the job description extraction section.

    Args:
        insights: Candidate insights dictionary
    """
    st.sidebar.header("🌐 Job Description Extraction")
    job_url = st.sidebar.text_input(
        "Job Description URL",
        placeholder="Enter URL of job description",
        help="Paste the URL of a job description to extract details",
        on_change=lambda: None,
    )

    job_details = _extract_job_details(job_url)

    if job_details:
        _assess_job_match(job_details, insights)


def _extract_job_details(job_url):
    """
    Extract job details from the provided URL.

    Args:
        job_url: URL of the job description

    Returns:
        Job details dictionary or None
    """
    if job_url:
        if st.sidebar.button(
            "Extract Job Details",
            type="primary",
            disabled=hasattr(st.session_state, "job_details"),
        ):
            st.session_state.show_scroll_message = True
            with st.spinner("Extracting job description..."):
                try:
                    result = extract_job_details(job_url)
                    job_details = json.loads(result[0]["value"])
                    st.session_state.job_details = job_details
                    # st.success("Job description extracted successfully!")
                except Exception as e:
                    st.error(f"An error occurred: {str(e)}")

        if hasattr(st.session_state, "job_details"):
            # Display job details
            st.subheader("📋 Job Description Details")
            st.markdown(
                f"**Job Title:** {st.session_state.job_details.get('job_title', 'N/A')}"
            )
            st.markdown(
                f"**Location:** {st.session_state.job_details.get('location', 'N/A')}"
            )
            st.markdown(
                f"**Salary:** {st.session_state.job_details.get('salary', 'N/A')}"
            )
            st.markdown(
                f"**Equity:** {st.session_state.job_details.get('equity', 'N/A')}"
            )
            st.markdown(
                f"**Experience Level:** {st.session_state.job_details.get('experience_level', 'N/A')}"
            )

            st.subheader("Key Responsibilities")
            for responsabilities in st.session_state.job_details.get(
                "key_responsibilities", []
            ):
                st.markdown(f"- {responsabilities}")

            st.subheader("Requirements")
            for requirements in st.session_state.job_details.get("requirements", []):
                st.markdown(f"- {requirements}")
            return st.session_state.job_details

    return None


def _assess_job_match(job_details, candidate_insights):
    """
    Assess the job match between candidate insights and job details.

    Args:
        job_details: Dictionary of job details
        candidate_insights: Dictionary of candidate insights
    """
    st.sidebar.header("🔍 Job Match Assessment")

    if st.sidebar.button("Assess Job Fit", type="primary"):
        with st.spinner("Analyzing candidate-job match..."):
            try:
                # Call job matching assessment function
                result = evaluate_candidate_job_fit(
                    json.dumps(candidate_insights), json.dumps(job_details)
                )

                if result:
                    match_assessment = json.loads(result[0]["value"])
                    _render_job_match_assessment(match_assessment)
                else:
                    st.error("Failed to assess job fit.")

            except Exception as e:
                st.error(f"An error occurred during job fit assessment: {str(e)}")


def _render_job_match_assessment(match_assessment):
    """
    Render the detailed job match assessment.

    Args:
        match_assessment: Dictionary containing job match assessment details
    """
    st.header("📊 Candidate-Job Fit Analysis")

    # Overall Match Percentage and Recommendation
    col1, col2, col3 = st.columns(3)

    with col1:
        st.metric(
            label="Overall Match",
            value=f"{match_assessment.get('percentage_match', 0)}%",
            help="Percentage of job requirements met by the candidate",
        )

    with col2:
        _render_recommendation(match_assessment)

    with col3:
        st.metric(
            label="Interview Potential",
            value=(
                "Good"
                if match_assessment.get("percentage_match", 0) > 70
                else "Needs Work"
            ),
            help="Candidate's potential for interview based on job match",
        )

    # Strengths and Skill Gaps
    _render_strengths(match_assessment)
    _render_skill_gaps(match_assessment)

    # Full Assessment View
    with st.expander("📄 Detailed Match Assessment"):
        st.json(match_assessment)


def _render_recommendation(match_assessment):
    """
    Render the overall recommendation with color coding.

    Args:
        match_assessment: Dictionary containing job match assessment details
    """
    recommendation = match_assessment.get("overall_recommendation", "Unknown")

    color_map = {
        "Strong Fit": ("green", "✅"),
        "Moderate Fit": ("orange", "⚠️"),
    }

    color, emoji = color_map.get(recommendation, ("red", "❌"))

    st.markdown(
        f"""
        <div style="background-color:{color}20; 
                    border-radius:10px; 
                    padding:10px; 
                    text-align:center;">
        <h4 style="color:{color};">
        {emoji} {recommendation}
        </h4>
        </div>
        """,
        unsafe_allow_html=True,
    )


def _render_strengths(match_assessment):
    """
    Render candidate strengths.

    Args:
        match_assessment: Dictionary containing job match assessment details
    """
    st.subheader("🌟 Candidate Strengths")
    strengths = match_assessment.get("strengths", [])

    if strengths:
        strength_cols = st.columns(3)
        for i, strength in enumerate(strengths):
            with strength_cols[i % 3]:
                st.markdown(
                    f"""
                    <div class="strengths">
                    {strength}
                    </div>
                    """,
                    unsafe_allow_html=True,
                )
    else:
        st.info("No specific strengths identified")


def _render_skill_gaps(match_assessment):
    """
    Render potential skill gaps.

    Args:
        match_assessment: Dictionary containing job match assessment details
    """
    st.subheader("🚧 Potential Skill Gaps")
    skill_gaps = match_assessment.get("potential_skill_gaps", [])

    if skill_gaps:
        gap_cols = st.columns(3)
        for i, gap in enumerate(skill_gaps):
            with gap_cols[i % 3]:
                st.markdown(
                    f"""
                    <div class="skill-gap">
                    {gap}
                    </div>
                    """,
                    unsafe_allow_html=True,
                )
    else:
        st.info("No significant skill gaps identified")


def _display_candidate_profile(candidate_data: Dict[str, Any]):
    """
    Display a detailed candidate profile.

    Args:
        candidate_data: Dictionary containing candidate information
    """
    st.header(f"🧑‍💼 {candidate_data.get('name', 'Candidate Profile')}")

    # Contact and Skills Overview
    col1, col2 = st.columns([1, 2])

    with col1:
        # Contact Information
        st.subheader("📧 Contact Information")
        st.markdown(f"**Email:** {candidate_data.get('email', 'Not provided')}")

        # Age (if available)
        if "age" in candidate_data:
            st.markdown(f"**Age:** {candidate_data['age']}")

    with col2:
        # Skills Section
        st.subheader("🛠️ Skills Overview")
        _render_skills(candidate_data.get("skills", []))

    # Skills Proficiency Visualization
    _create_skills_chart(candidate_data.get("skills", []))

    # Full JSON Response
    with st.expander("📄 Full JSON Response"):
        st.json(candidate_data)


def _render_skills(skills):
    """
    Render skills with badges and proficiency.

    Args:
        skills: List of skill dictionaries
    """
    if skills:
        skills_html = ""
        for skill in skills:
            skill_name = skill.get("name", "Unnamed Skill")
            proficiency = skill.get("proficiency")

            if proficiency is not None:
                proficiency_label = _get_proficiency_label(proficiency)
                skills_html += (
                    f'<span class="skill-badge">{skill_name}'
                    f'<span class="skill-proficiency">{proficiency_label}</span>'
                    f"</span> "
                )
            else:
                skills_html += f'<span class="skill-badge">{skill_name}</span> '

        st.markdown(skills_html, unsafe_allow_html=True)
    else:
        st.markdown("*No skills listed*")


def _get_proficiency_label(proficiency):
    """
    Get a readable proficiency label.

    Args:
        proficiency: Numeric proficiency level

    Returns:
        Proficiency label as a string
    """
    if proficiency <= 2:
        return "Beginner"
    elif proficiency <= 4:
        return "Intermediate"
    else:
        return "Advanced"


def _create_skills_chart(skills):
    """
    Create skills proficiency visualization.

    Args:
        skills: List of skill dictionaries
    """
    st.subheader("📊 Skills Proficiency")

    if skills:
        # Prepare data for the chart
        chart_data = [
            {
                "skill": skill.get("name", "Unnamed Skill"),
                "proficiency": skill.get("proficiency", 0),
            }
            for skill in skills
        ]

        # Convert to DataFrame
        df = pd.DataFrame(chart_data)

        # Create visualization tabs
        tab1, tab2 = st.tabs(["Bar Chart", "Table View"])

    with tab1:
        # Altair Bar Chart with improved styling
        chart = (
            alt.Chart(df)
            .mark_bar(
                color="#4CAF50",  # Green color to match other design elements
                opacity=0.7,
            )
            .encode(
                x=alt.X("skill:N", title="Skills", sort="-y"),
                y=alt.Y(
                    "proficiency:Q",
                    title="Proficiency Level",
                    scale=alt.Scale(domain=[0, max(df["proficiency"]) * 1.2]),
                ),
                tooltip=["skill", "proficiency"],
            )
            .properties(width=600, height=400, title="Skills Proficiency Breakdown")
            .configure_title(fontSize=16, font="Arial", anchor="middle")
        )

        st.altair_chart(chart, use_container_width=True)

    with tab2:
        # Enhanced Table View
        styled_df = df.style.background_gradient(cmap="Greens", subset=["proficiency"])
        st.dataframe(styled_df, use_container_width=True)


# Run the Streamlit app
if __name__ == "__main__":
    __init__()
    run()