app.py

# app.py

import os
import base64
from io import BytesIO

import streamlit as st
from PyPDF2 import PdfReader
from docx import Document

from prompts import generate_cover_letter_prompt
from hf_inference import query_llama3

# ---------------- PAGE CONFIG (FULL WIDTH) ----------------
st.set_page_config(
    page_title="InkApply – AI Cover Letter Generator",
    page_icon="Inkapply-logo.png" if os.path.exists("Inkapply-logo.png") else "📝",
    layout="wide",
)

# ---------------- CACHE MODEL (anti-buffering fix) ----------------
@st.cache_resource(show_spinner="Loading AI model… (first run only)")
def get_llm():
    return True

get_llm()

# ---------------- SESSION STATE DEFAULTS ----------------
st.session_state.setdefault("resume_bytes", None)
st.session_state.setdefault("resume_content", "")
st.session_state.setdefault("uploaded_file_name", "")
st.session_state.setdefault("cover_letter", "")

# ---------------- GLOBAL STYLING (LEFT, FULL-WIDTH) ----------------
st.markdown(
    """
    <style>
    .block-container {
        padding-top: 2.75rem !important;
        max-width: 100% !important;
        padding-left: 2.5rem !important;
        padding-right: 2.5rem !important;
    }

    @import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600&display=swap');
    html, body, [class*="css"] { font-family: 'Inter', sans-serif; }

    section[data-testid="stSidebar"] { padding-top: 1rem; }
    .sidebar-logo { display: flex; justify-content: center; padding: 0.5rem 0 1rem 0; }
    .sidebar-logo img { border-radius: 50%; width: 88px; height: 88px; object-fit: cover; border: 1px solid #2a2a2a; }

    textarea, input {
        background-color: #1f1f1f !important;
        border: 1px solid #2b2b2b !important;
        border-radius: 12px !important;
        padding: 0.75rem !important;
        color: #ffffff !important;
    }

    /* Hide Streamlit branding */
    #MainMenu {visibility: hidden;}
    footer {visibility: hidden;}
    header {visibility: hidden;}

    textarea::placeholder, input::placeholder { color: #9aa0a6 !important; }
    textarea:focus, input:focus {
        border-color: #10A37F !important;
        box-shadow: 0 0 0 1px rgba(16,163,127,0.45);
        outline: none !important;
    }

    .ink-nb {
        margin-top: 0.5rem;
        font-size: 0.78rem;
        color: #9aa0a6;
        font-style: italic;
    }
    .ink-nb span {
        color: #f0a500;
        font-weight: 600;
        font-style: normal;
    }
    </style>
    """,
    unsafe_allow_html=True,
)

# ---------------- SIDEBAR LOGO ----------------
logo_path = "Inkapply-logo.png"
if os.path.exists(logo_path):
    with open(logo_path, "rb") as f:
        logo_base64 = base64.b64encode(f.read()).decode()
    st.sidebar.markdown(
        f'<div class="sidebar-logo"><img src="data:image/png;base64,{logo_base64}" /></div>',
        unsafe_allow_html=True
    )
else:
    st.sidebar.markdown("### InkApply")

st.sidebar.markdown("<p style='color:#9aa0a6; text-align:center;'>AI Resume & Cover Letter Generator</p>", unsafe_allow_html=True)

# ---------------- HERO ----------------
st.markdown(
    "<h3 style='margin-bottom:0.35rem;'>AI Cover Letter Generator</h3>"
    "<p style='color:#9aa0a6; margin-top:0;'>Create tailored cover letters in seconds.</p>",
    unsafe_allow_html=True,
)

# ---------------- INPUTS ----------------
job_title = st.text_input("", placeholder="Job title (e.g. Senior Embedded Software Engineer)")
job_description = st.text_area("", placeholder="Paste the job description here (optional but recommended)", height=160)

# ---------------- FILE PARSER ----------------
def parse_uploaded_file(file_bytes: bytes, filename: str) -> str:
    """Return text from PDF, DOCX, or TXT in a Streamlit-safe way."""
    try:
        fn = filename.lower()
        if fn.endswith(".pdf"):
            reader = PdfReader(BytesIO(file_bytes))
            text = [page.extract_text() for page in reader.pages if page.extract_text()]
            return "\n".join(text).strip()
        if fn.endswith(".docx"):
            doc = Document(BytesIO(file_bytes))
            text = [p.text for p in doc.paragraphs if p.text.strip()]
            return "\n".join(text).strip()
        if fn.endswith(".txt"):
            return file_bytes.decode("utf-8", errors="ignore").strip()
        return ""
    except Exception as e:
        st.error(f"Failed to read file: {e}")
        return ""

# ---------------- FILE UPLOADER (with KEY) ----------------
uploaded_file = st.file_uploader(
    "Upload your resume (PDF preferred, DOCX/TXT supported)",
    type=["pdf", "docx", "txt"],
    key="resume_uploader",
)

if uploaded_file is not None:
    try:
        file_bytes = uploaded_file.read()
        st.session_state.resume_bytes = file_bytes
        st.session_state.uploaded_file_name = uploaded_file.name

        parsed_text = parse_uploaded_file(file_bytes, uploaded_file.name)
        if parsed_text:
            st.session_state.resume_content = parsed_text
            st.success(f"Resume '{uploaded_file.name}' loaded successfully!")
        else:
            st.warning("Could not extract text. Please paste your resume below.")
    except Exception as e:
        st.error(f"Upload failed: {e}")

if uploaded_file is None and st.session_state.get("resume_bytes") and not st.session_state.get("resume_content"):
    parsed_text = parse_uploaded_file(st.session_state.resume_bytes, st.session_state.uploaded_file_name or "resume")
    if parsed_text:
        st.session_state.resume_content = parsed_text

if st.session_state.get("uploaded_file_name"):
    st.info(f"Uploaded: {st.session_state.uploaded_file_name}")

# ---------------- MANUAL RESUME INPUT (preview + editable) ----------------
new_text = st.text_area(
    label=(
        f"Resume content (from uploaded file: {st.session_state.uploaded_file_name})"
        if st.session_state.uploaded_file_name else "Resume content"
    ),
    value=st.session_state.get("resume_content", ""),
    placeholder="Or paste your resume content here…",
    height=260,
    key="resume_textarea",
)

if new_text != st.session_state.get("resume_content", ""):
    st.session_state.resume_content = new_text

# ---------------- GENERATE COVER LETTER ----------------
if st.button("Generate cover letter ✨"):
    if not job_title.strip():
        st.warning("Please enter a job title.")
    elif not st.session_state.get("resume_content", "").strip():
        st.warning("Please upload or paste your resume.")
    else:
        trimmed_resume = " ".join(st.session_state.resume_content.split()[:300])
        trimmed_desc = " ".join((job_description or "").split()[:200])

        prompt = generate_cover_letter_prompt(
            job_title.strip(),
            trimmed_desc,
            trimmed_resume,
        )

        with st.spinner("Generating your cover letter…"):
            try:
                generated_text = query_llama3(prompt)
                st.session_state.cover_letter = generated_text.strip()
            except Exception as e:
                st.error(f"Generation failed: {e}")

# ---------------- N.B NOTE ----------------
st.markdown(
    "<p class='ink-nb'><span>•</span> N.B Review the cover letter output and regenerate if any errors occurred "
    "before downloading. InkApply can make mistakes.</p>",
    unsafe_allow_html=True,
)

# ---------------- RESULT (persists across reruns) ----------------
if st.session_state.cover_letter:
    st.markdown("### Your cover letter")
    st.text_area("", value=st.session_state.cover_letter, height=360)

    # TXT download
    st.download_button(
        "Download TXT",
        st.session_state.cover_letter,
        "cover_letter.txt",
        "text/plain",
    )

    # DOCX download
    doc = Document()
    doc.add_heading(f"Cover Letter – {job_title}", 0)
    doc.add_paragraph(st.session_state.cover_letter)

    buffer = BytesIO()
    doc.save(buffer)
    buffer.seek(0)

    st.download_button(
        "Download Word (.docx)",
        buffer,
        "cover_letter.docx",
        "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
    )