from flask import Flask, render_template, request, redirect
from db import get_db_connection
from utils import generate_client_code, generate_service_code

app = Flask(
    __name__,
    template_folder="../templates",
    static_folder="../static",
)

@app.route("/")
def index():
    conn = get_db_connection()
    cursor = conn.cursor(dictionary=True)

    cursor.execute("SELECT COUNT(*) AS total_clients FROM clients")
    total_clients = cursor.fetchone()["total_clients"]

    cursor.execute("SELECT COUNT(*) AS active_services FROM services WHERE status = 'active'")
    active_services = cursor.fetchone()["active_services"]

    cursor.execute("""
        SELECT COUNT(*) AS outstanding_invoices
        FROM invoices
        WHERE status IN ('pending', 'partial', 'overdue')
    """)
    outstanding_invoices = cursor.fetchone()["outstanding_invoices"]

    cursor.execute("""
        SELECT COALESCE(SUM(payment_amount), 0) AS revenue_received
        FROM payments
        WHERE payment_status = 'confirmed'
          AND payment_currency = 'CAD'
    """)
    revenue_received = cursor.fetchone()["revenue_received"]

    conn.close()

    return render_template(
        "dashboard.html",
        total_clients=total_clients,
        active_services=active_services,
        outstanding_invoices=outstanding_invoices,
        revenue_received=revenue_received,
    )

@app.route("/dbtest")
def dbtest():
    try:
        conn = get_db_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT NOW()")
        result = cursor.fetchone()
        conn.close()
        return f"<h1>Database OK</h1><p>{result[0]}</p>"
    except Exception as e:
        return f"<h1>Database FAILED</h1><pre>{e}</pre>"

@app.route("/clients")
def clients():
    conn = get_db_connection()
    cursor = conn.cursor(dictionary=True)
    cursor.execute("SELECT * FROM clients ORDER BY id DESC")
    clients = cursor.fetchall()
    conn.close()
    return render_template("clients/list.html", clients=clients)

@app.route("/services")
def services():
    conn = get_db_connection()
    cursor = conn.cursor(dictionary=True)
    cursor.execute("""
        SELECT s.*, c.client_code, c.company_name
        FROM services s
        JOIN clients c ON s.client_id = c.id
        ORDER BY s.id DESC
    """)
    services = cursor.fetchall()
    conn.close()
    return render_template("services/list.html", services=services)

@app.route("/invoices")
def invoices():
    conn = get_db_connection()
    cursor = conn.cursor(dictionary=True)
    cursor.execute("""
        SELECT
            i.*,
            c.client_code,
            c.company_name
        FROM invoices i
        JOIN clients c ON i.client_id = c.id
        ORDER BY i.id DESC
    """)
    invoices = cursor.fetchall()
    conn.close()
    return render_template("invoices/list.html", invoices=invoices)

@app.route("/invoices/new", methods=["GET", "POST"])
def new_invoice():
    conn = get_db_connection()
    cursor = conn.cursor(dictionary=True)

    if request.method == "POST":
        client_id = request.form.get("client_id", "").strip()
        service_id = request.form.get("service_id", "").strip()
        currency_code = request.form.get("currency_code", "").strip()
        total_amount = request.form.get("total_amount", "").strip()
        due_at = request.form.get("due_at", "").strip()
        notes = request.form.get("notes", "").strip()

        errors = []

        if not client_id:
            errors.append("Client is required.")
        if not service_id:
            errors.append("Service is required.")
        if not currency_code:
            errors.append("Currency is required.")
        if not total_amount:
            errors.append("Total amount is required.")
        if not due_at:
            errors.append("Due date is required.")

        if not errors:
            try:
                amount_value = float(total_amount)
                if amount_value <= 0:
                    errors.append("Total amount must be greater than zero.")
            except ValueError:
                errors.append("Total amount must be a valid number.")

        if errors:
            cursor.execute("""
                SELECT id, client_code, company_name
                FROM clients
                ORDER BY company_name
            """)
            clients = cursor.fetchall()

            cursor.execute("""
                SELECT id, service_code, service_name
                FROM services
                ORDER BY service_name
            """)
            services = cursor.fetchall()

            conn.close()

            form_data = {
                "client_id": client_id,
                "service_id": service_id,
                "currency_code": currency_code,
                "total_amount": total_amount,
                "due_at": due_at,
                "notes": notes,
            }

            return render_template(
                "invoices/new.html",
                clients=clients,
                services=services,
                errors=errors,
                form_data=form_data,
            )

        cursor.execute("SELECT MAX(id) AS last_id FROM invoices")
        result = cursor.fetchone()

        number = (result["last_id"] or 0) + 1
        invoice_number = f"INV-{number:04d}"

        insert = conn.cursor()
        insert.execute("""
            INSERT INTO invoices
            (
                client_id,
                service_id,
                invoice_number,
                currency_code,
                total_amount,
                subtotal_amount,
                issued_at,
                due_at,
                status,
                notes
            )
            VALUES (%s, %s, %s, %s, %s, %s, NOW(), %s, 'pending', %s)
        """, (
            client_id,
            service_id,
            invoice_number,
            currency_code,
            total_amount,
            total_amount,
            due_at,
            notes
        ))

        conn.commit()
        conn.close()

        return redirect("/invoices")

    cursor.execute("""
        SELECT id, client_code, company_name
        FROM clients
        ORDER BY company_name
    """)
    clients = cursor.fetchall()

    cursor.execute("""
        SELECT id, service_code, service_name
        FROM services
        ORDER BY service_name
    """)
    services = cursor.fetchall()

    conn.close()

    return render_template(
        "invoices/new.html",
        clients=clients,
        services=services,
        errors=[],
        form_data={},
    )

@app.route("/clients/new", methods=["GET", "POST"])
def new_client():
    if request.method == "POST":
        company_name = request.form["company_name"]
        contact_name = request.form["contact_name"]
        email = request.form["email"]
        phone = request.form["phone"]

        conn = get_db_connection()
        cursor = conn.cursor(dictionary=True)
        cursor.execute("SELECT MAX(id) AS last_id FROM clients")
        result = cursor.fetchone()
        last_number = result["last_id"] if result["last_id"] else 0

        client_code = generate_client_code(company_name, last_number)

        cursor = conn.cursor()
        cursor.execute(
            """
            INSERT INTO clients
            (client_code, company_name, contact_name, email, phone)
            VALUES (%s, %s, %s, %s, %s)
            """,
            (client_code, company_name, contact_name, email, phone)
        )
        conn.commit()
        conn.close()

        return redirect("/clients")

    return render_template("clients/new.html")

@app.route("/services/new", methods=["GET", "POST"])
def new_service():
    conn = get_db_connection()
    cursor = conn.cursor(dictionary=True)

    if request.method == "POST":
        client_id = request.form["client_id"]
        service_name = request.form["service_name"]
        service_type = request.form["service_type"]
        billing_cycle = request.form["billing_cycle"]
        currency_code = request.form["currency_code"]
        recurring_amount = request.form["recurring_amount"]
        status = request.form["status"]
        start_date = request.form["start_date"] or None
        description = request.form["description"]

        cursor.execute("SELECT MAX(id) AS last_id FROM services")
        result = cursor.fetchone()
        last_number = result["last_id"] if result["last_id"] else 0
        service_code = generate_service_code(service_name, last_number)

        insert_cursor = conn.cursor()
        insert_cursor.execute(
            """
            INSERT INTO services
            (
                client_id,
                service_code,
                service_name,
                service_type,
                billing_cycle,
                status,
                currency_code,
                recurring_amount,
                start_date,
                description
            )
            VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
            """,
            (
                client_id,
                service_code,
                service_name,
                service_type,
                billing_cycle,
                status,
                currency_code,
                recurring_amount,
                start_date,
                description
            )
        )
        conn.commit()
        conn.close()

        return redirect("/services")

    cursor.execute("SELECT id, client_code, company_name FROM clients ORDER BY company_name ASC")
    clients = cursor.fetchall()
    conn.close()
    return render_template("services/new.html", clients=clients)

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5050)