from flask import Blueprint, render_template, current_app, request, flash, redirect, url_for
from .models import ScheduleConfig, VolumeConfig, PaperMetadata
from .db import db
import pandas as pd
from io import StringIO
import codecs

bp = Blueprint('main', __name__)


@bp.route("/")
def index():
    return render_template("index.html")

REQUIRED_COLUMNS = {"alternative_id", "journal", "doi", "issn", "title"}


@bp.route('/upload', methods=['GET', 'POST'])
def upload():
    if request.method == 'POST':
        file = request.files.get('file')
        delimiter = request.form.get('delimiter', ',')

        if not file:
            return render_template('upload.html', error="No file selected.")

        try:
            stream = codecs.iterdecode(file.stream, 'utf-8')
            content = ''.join(stream)
            df = pd.read_csv(StringIO(content), delimiter=delimiter)
        except Exception as e:
            return render_template('upload.html', error=f"Failed to read CSV file: {e}")

        missing = REQUIRED_COLUMNS - set(df.columns)
        if missing:
            return render_template('upload.html', error=f"Missing required columns: {', '.join(missing)}")

        # Optional: parse 'published_online' to date
        def parse_date(val):
            if pd.isna(val):
                return None
            try:
                return pd.to_datetime(val).date()
            except Exception:
                return None

        for _, row in df.iterrows():
            metadata = PaperMetadata(
                title=row['title'],
                doi=row['doi'],
                alt_id=row.get('alternative_id'),
                issn=row['issn'],
                type=row.get('type'),
                language=row.get('language'),
                published_online=parse_date(row.get('published_online')),
                status=None,
                file_path=None,
                error_msg=None
            )
            db.session.add(metadata)

        try:
            db.session.commit()
        except Exception as e:
            db.session.rollback()
            return render_template('upload.html', error=f"Failed to save data to database: {e}")

        return render_template('upload.html', success="File uploaded and validated successfully!")

    return render_template('upload.html')



@bp.route("/papers")
def papers():
    return render_template("papers.html", app_title="PaperScraper")


@bp.route("/schedule", methods=["GET", "POST"])
def schedule():
    if request.method == "POST":
        try:
            # Check if we're updating volume or schedule
            if 'total_volume' in request.form:
                # Volume update
                try:
                    new_volume = float(request.form.get('total_volume', 0))
                    if new_volume <= 0 or new_volume > 1000:
                        raise ValueError("Volume must be between 1 and 1000")

                    volume_config = VolumeConfig.query.first()
                    if not volume_config:
                        volume_config = VolumeConfig(volume=new_volume)
                        db.session.add(volume_config)
                    else:
                        volume_config.volume = new_volume

                    db.session.commit()
                    flash("Volume updated successfully!", "success")

                except ValueError as e:
                    db.session.rollback()
                    flash(f"Error updating volume: {str(e)}", "error")
            else:
                # Schedule update logic
                # Validate form data
                for hour in range(24):
                    key = f"hour_{hour}"
                    if key not in request.form:
                        raise ValueError(f"Missing data for hour {hour}")

                    try:
                        weight = float(request.form.get(key, 0))
                        if weight < 0 or weight > 5:
                            raise ValueError(
                                f"Weight for hour {hour} must be between 0 and 5")
                    except ValueError:
                        raise ValueError(f"Invalid weight value for hour {hour}")

                # Update database if validation passes
                for hour in range(24):
                    key = f"hour_{hour}"
                    weight = float(request.form.get(key, 0))
                    config = ScheduleConfig.query.get(hour)
                    if config:
                        config.weight = weight
                    else:
                        db.session.add(ScheduleConfig(hour=hour, weight=weight))

                db.session.commit()
                flash("Schedule updated successfully!", "success")

        except ValueError as e:
            db.session.rollback()
            flash(f"Error updating schedule: {str(e)}", "error")

    schedule = {sc.hour: sc.weight for sc in ScheduleConfig.query.order_by(
        ScheduleConfig.hour).all()}
    volume = VolumeConfig.query.first()
    return render_template("schedule.html", schedule=schedule, volume=volume.volume, app_title="PaperScraper")


@bp.route("/logs")
def logs():
    return render_template("logs.html", app_title="PaperScraper")


@bp.route("/about")
def about():
    return render_template("about.html", app_title="PaperScraper")