import gradio as gr
import csv # Import csv here as well if not importing the whole validator.py

# You can either paste the validate_tsv_file function directly here
# OR import it if it's in a separate file (e.g., from validator import validate_tsv_file)

# --- Paste the validate_tsv_file function here if not importing ---
def validate_tsv_file(file_path):
    """
    Validates a TSV file according to the specified rules.

    Args:
        file_path (str): The path to the TSV file.

    Returns:
        str: A message indicating whether the file is valid or listing errors.
    """
    errors = []
    last_end_time = None  # To store the end_time of the previous row

    try:
        with open(file_path, 'r', encoding='utf-8', newline='') as tsvfile:
            reader = csv.reader(tsvfile, delimiter='\t')
            for row_num, row in enumerate(reader, 1):
                # Check for correct number of columns
                if len(row) != 3:
                    errors.append(f"Row {row_num}: Expected 3 columns, but found {len(row)}. Content: '{' | '.join(row)}'")
                    last_end_time = None 
                    continue

                start_time_str, end_time_str, text_content = row

                # Validate timestamps are numbers
                try:
                    start_time = float(start_time_str)
                    end_time = float(end_time_str)
                except ValueError:
                    errors.append(f"Row {row_num}: Timestamps must be numeric. Found start='{start_time_str}', end='{end_time_str}'.")
                    last_end_time = None
                    continue

                # Rule 1: End timestamp > Start timestamp
                if end_time <= start_time:
                    errors.append(f"Row {row_num}: End timestamp ({end_time}) must be greater than start timestamp ({start_time}).")

                # Rule 2: Current row's start_time > previous row's end_time
                if last_end_time is not None:
                    if start_time <= last_end_time: # Must be strictly greater
                        errors.append(f"Row {row_num}: Start timestamp ({start_time}) must be greater than the previous segment's end timestamp ({last_end_time}).")
                
                last_end_time = end_time

    except FileNotFoundError:
        return f"Error: File not found at '{file_path}'."
    except Exception as e:
        return f"An unexpected error occurred: {str(e)}"

    if not errors:
        return "TSV file is valid and follows all timestamp rules!"
    else:
        return "TSV file has the following issues:\n" + "\n".join(errors)
# --- End of pasted/imported function ---


def handle_validation(uploaded_file_obj):
    if uploaded_file_obj is None:
        return "Please upload a TSV file first."
    
    # Gradio provides a temporary file object. We need its path.
    file_path = uploaded_file_obj.name 
    
    return validate_tsv_file(file_path)

# --- Gradio Interface Definition ---
iface = gr.Interface(
    fn=handle_validation,
    inputs=gr.File(label="Upload TSV File (.tsv or .txt)", file_types=[".tsv", ".txt"]),
    outputs=gr.Textbox(label="Validation Result", lines=15, show_copy_button=True),
    title="TSV Timestamp Validator",
    description="Upload a TSV file with columns: `start_timestamp` (tab) `end_timestamp` (tab) `text`. "
                "This tool checks if: \n"
                "1. Each row has 3 columns.\n"
                "2. Timestamps are numeric.\n"
                "3. End timestamp > Start timestamp for each segment.\n"
                "4. Start timestamp of a segment > End timestamp of the previous segment.",
    allow_flagging="never" # Usually not needed for utility apps
)

if __name__ == "__main__":
    iface.launch()