import base64

from flask import Flask, request, render_template

from analyzer.parser import parse_csv
from analyzer.grouper import detect_groups
from analyzer.stats import compute_overall_stats, compute_group_stats
from analyzer.charts import render_group_charts, render_overview_chart
from analyzer.pdf_report import generate_pdf

app = Flask(__name__)
app.config["MAX_CONTENT_LENGTH"] = 16 * 1024 * 1024


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


@app.route("/analyze", methods=["POST"])
def analyze():
    if "csv_file" not in request.files or request.files["csv_file"].filename == "":
        return render_template("upload.html", error="No file selected.")

    file = request.files["csv_file"]

    try:
        df = parse_csv(file.stream)
        groups = detect_groups(df)
        overall = compute_overall_stats(df)
        group_stats = compute_group_stats(groups)
        charts = render_group_charts(
            groups,
            y_min=overall["min_speed"],
            y_max=overall["max_speed"],
        )
        overview_chart = render_overview_chart(group_stats)
    except ValueError as e:
        return render_template("upload.html", error=str(e))

    pdf_bytes = generate_pdf(overall, group_stats, charts, overview_chart)
    pdf_b64 = base64.b64encode(pdf_bytes).decode("utf-8")

    groups_display = list(zip(group_stats, charts))
    return render_template(
        "results.html",
        overall=overall,
        groups_display=groups_display,
        overview_chart=overview_chart,
        pdf_b64=pdf_b64,
    )


if __name__ == "__main__":
    app.run(debug=True)