import pandas as pd

CSV_FILE = "filename.csv"

df = pd.read_csv(CSV_FILE, sep=";", encoding="utf-8-sig")

# Parse dates
date_cols = ["Original Due Date", "Due Date", "Window Start Date", "Cutoff Date", "Completed Date"]
for col in date_cols:
    df[col] = pd.to_datetime(df[col], errors="coerce")

# Country from site number
df["Country"] = df["Study Site Number"].str.extract(r"DD5-([A-Z]+)\d+")

print("=" * 60)
print("CTMS VISITS EXPORT — přehled dat")
print("=" * 60)
print(f"\nCelkem řádků : {len(df):,}")
print(f"Celkem sloupců: {len(df.columns)}")
print(f"\nSloupce:\n  " + "\n  ".join(df.columns.tolist()))

print(f"\nSites celkem : {df['Study Site Number'].nunique()}")
print(f"Zemí celkem  : {df['Country'].nunique()}")
print(f"Země         : {', '.join(sorted(df['Country'].dropna().unique()))}")

print("\nStatus:")
for k, v in df["Status"].value_counts().items():
    print(f"  {k:<20} {v:>6,}")

print("\nCategory:")
for k, v in df["Category"].value_counts().items():
    print(f"  {k:<25} {v:>6,}")

print("\nSub Category:")
for k, v in df["Sub Category"].value_counts().items():
    print(f"  {k:<20} {v:>6,}")

print(f"\nReference kódy: {sorted(df['Reference'].dropna().unique().tolist())}")

print("\nRozsah dat:")
for col in ["Due Date", "Completed Date"]:
    vals = df[col].dropna()
    if len(vals):
        print(f"  {col:<20} {vals.min().date()} — {vals.max().date()}")

print("\nNáhled (5 řádků):")
print(df.head(5).to_string())