"""
Cebuano Fake News Data Entry Tool
===================================
Manually input Cebuano fake news articles into
data/raw/augmented_ceb_fakes.csv for model training.

Usage:
    python add_cebuano_data.py

Features:
    - Interactive CLI with menu options
    - Paste single-line or multi-line articles
    - Preview entries before saving
    - View existing dataset stats
    - Duplicate detection (warns if near-identical text exists)
"""

import csv
import os
import sys
import textwrap
from datetime import datetime

# ── Paths ──
SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
CSV_PATH = os.path.join(SCRIPT_DIR, "data", "raw", "augmented_ceb_fakes.csv")
BACKUP_DIR = os.path.join(SCRIPT_DIR, "data", "raw", ".backups")


def _count_existing_rows() -> int:
    """Count how many articles are already in the CSV."""
    if not os.path.exists(CSV_PATH):
        return 0
    with open(CSV_PATH, "r", encoding="utf-8") as f:
        reader = csv.reader(f)
        header = next(reader, None)
        return sum(1 for _ in reader)


def _load_existing_articles() -> list[str]:
    """Load all existing article texts (for duplicate checking)."""
    articles = []
    if not os.path.exists(CSV_PATH):
        return articles
    with open(CSV_PATH, "r", encoding="utf-8") as f:
        reader = csv.reader(f)
        next(reader, None)  # skip header
        for row in reader:
            if row:
                articles.append(row[0].strip().lower())
    return articles


def _is_duplicate(new_text: str, existing: list[str], threshold: int = 50) -> bool:
    """Check if the first `threshold` characters match any existing article."""
    snippet = new_text.strip().lower()[:threshold]
    if len(snippet) < 20:
        return False
    for art in existing:
        if art[:threshold] == snippet:
            return True
    return False


def _backup_csv():
    """Create a timestamped backup of the current CSV."""
    if not os.path.exists(CSV_PATH):
        return
    os.makedirs(BACKUP_DIR, exist_ok=True)
    ts = datetime.now().strftime("%Y%m%d_%H%M%S")
    backup_path = os.path.join(BACKUP_DIR, f"augmented_ceb_fakes_{ts}.csv")
    with open(CSV_PATH, "r", encoding="utf-8") as src:
        with open(backup_path, "w", encoding="utf-8", newline="") as dst:
            dst.write(src.read())
    print(f"  Backup saved: {os.path.relpath(backup_path, SCRIPT_DIR)}")


def _ensure_csv_exists():
    """Create the CSV with header if it doesn't exist yet."""
    if not os.path.exists(CSV_PATH):
        os.makedirs(os.path.dirname(CSV_PATH), exist_ok=True)
        with open(CSV_PATH, "w", encoding="utf-8", newline="") as f:
            writer = csv.writer(f)
            writer.writerow(["article"])
        print(f"  Created new CSV: {CSV_PATH}")


def _append_articles(articles: list[str]):
    """Append a list of article texts to the CSV."""
    with open(CSV_PATH, "a", encoding="utf-8", newline="") as f:
        writer = csv.writer(f)
        for text in articles:
            writer.writerow([text])


def _preview_text(text: str, width: int = 80) -> str:
    """Return a truncated preview of article text."""
    preview = text.replace("\n", " ").strip()
    if len(preview) > width:
        return preview[:width] + "..."
    return preview


# ── CLI Display ──

def print_header():
    print()
    print("=" * 60)
    print("   CEBUANO FAKE NEWS — DATA ENTRY TOOL")
    print("=" * 60)
    print(f"  CSV: {os.path.relpath(CSV_PATH, SCRIPT_DIR)}")
    print(f"  Existing articles: {_count_existing_rows():,}")
    print("=" * 60)


def print_menu():
    print()
    print("  [1] Add a single article")
    print("  [2] Add multiple articles (batch mode)")
    print("  [3] View dataset stats")
    print("  [4] View last 5 entries")
    print("  [5] Exit")
    print()


def input_single_article() -> str | None:
    """Prompt the user to type/paste a single article.
    
    Supports multi-line input: type on multiple lines, then enter
    a blank line to finish.
    """
    print()
    print("  Paste or type the Cebuano fake news article below.")
    print("  (Enter a blank line when done, or type 'cancel' to abort)")
    print("  " + "-" * 50)

    lines = []
    while True:
        try:
            line = input("  > ")
        except EOFError:
            break
        if line.strip().lower() == "cancel":
            return None
        if line.strip() == "" and lines:
            break
        lines.append(line)

    text = " ".join(lines).strip()
    if not text:
        print("  (empty input — skipped)")
        return None
    return text


def add_single_article():
    """Menu option 1: add one article."""
    _ensure_csv_exists()
    existing = _load_existing_articles()
    
    text = input_single_article()
    if text is None:
        print("  Cancelled.")
        return

    # Duplicate check
    if _is_duplicate(text, existing):
        print()
        print("  ⚠  WARNING: This article appears to be a duplicate!")
        confirm = input("  Add anyway? (y/n): ").strip().lower()
        if confirm != "y":
            print("  Skipped.")
            return

    # Preview and confirm
    print()
    print("  Preview:")
    print(f"    {_preview_text(text, 100)}")
    print(f"    Length: {len(text):,} chars, {len(text.split()):,} words")
    print()
    confirm = input("  Save this article? (y/n): ").strip().lower()
    if confirm != "y":
        print("  Discarded.")
        return

    _append_articles([text])
    print(f"  ✓ Article saved! Total articles now: {_count_existing_rows():,}")


def add_batch_articles():
    """Menu option 2: add multiple articles in batch."""
    _ensure_csv_exists()
    existing = _load_existing_articles()
    
    print()
    print("  BATCH MODE — Enter one article per prompt.")
    print("  Type 'done' when finished, 'cancel' to discard all.")
    print()

    pending: list[str] = []
    article_num = 1

    while True:
        print(f"  --- Article #{article_num} ---")
        text = input_single_article()
        
        if text is None:
            # Check if user typed cancel
            break
            
        if _is_duplicate(text, existing):
            print("  ⚠  Possible duplicate — skipping this one.")
            continue

        pending.append(text)
        print(f"  ✓ Queued ({len(pending)} pending)")
        article_num += 1

        cont = input("  Add another? (y/n/done): ").strip().lower()
        if cont in ("n", "done"):
            break

    if not pending:
        print("  No articles to save.")
        return

    # Preview all
    print()
    print(f"  === {len(pending)} articles ready to save ===")
    for i, art in enumerate(pending, 1):
        print(f"    {i}. {_preview_text(art, 70)}")
    print()

    confirm = input(f"  Save all {len(pending)} articles? (y/n): ").strip().lower()
    if confirm != "y":
        print("  Discarded all.")
        return

    _backup_csv()
    _append_articles(pending)
    print(f"  ✓ {len(pending)} articles saved! Total now: {_count_existing_rows():,}")


def show_stats():
    """Menu option 3: show dataset statistics."""
    if not os.path.exists(CSV_PATH):
        print("  CSV not found — no data yet.")
        return

    articles = _load_existing_articles()
    total = len(articles)
    if total == 0:
        print("  Dataset is empty.")
        return

    word_counts = [len(a.split()) for a in articles]
    char_counts = [len(a) for a in articles]

    print()
    print("  ╔══════════════════════════════════════╗")
    print("  ║       DATASET STATISTICS             ║")
    print("  ╠══════════════════════════════════════╣")
    print(f"  ║  Total articles:    {total:>10,}      ║")
    print(f"  ║  Avg words/article: {sum(word_counts)//total:>10,}      ║")
    print(f"  ║  Min words:         {min(word_counts):>10,}      ║")
    print(f"  ║  Max words:         {max(word_counts):>10,}      ║")
    print(f"  ║  Avg chars/article: {sum(char_counts)//total:>10,}      ║")
    print(f"  ║  CSV size:          {os.path.getsize(CSV_PATH):>10,} B   ║")
    print("  ╚══════════════════════════════════════╝")
    print()


def show_last_entries():
    """Menu option 4: show last 5 entries."""
    if not os.path.exists(CSV_PATH):
        print("  CSV not found — no data yet.")
        return

    articles = []
    with open(CSV_PATH, "r", encoding="utf-8") as f:
        reader = csv.reader(f)
        next(reader, None)
        for row in reader:
            if row:
                articles.append(row[0])

    if not articles:
        print("  No articles in dataset.")
        return

    last5 = articles[-5:]
    print()
    print(f"  Last {len(last5)} entries (of {len(articles)} total):")
    print("  " + "-" * 50)
    for i, art in enumerate(last5, len(articles) - len(last5) + 1):
        print(f"    #{i}: {_preview_text(art, 70)}")
    print()


# ── Main Loop ──

def main():
    print_header()

    while True:
        print_menu()
        try:
            choice = input("  Choose an option [1-5]: ").strip()
        except (EOFError, KeyboardInterrupt):
            print("\n  Goodbye!")
            break

        if choice == "1":
            add_single_article()
        elif choice == "2":
            add_batch_articles()
        elif choice == "3":
            show_stats()
        elif choice == "4":
            show_last_entries()
        elif choice == "5":
            print("  Goodbye!")
            break
        else:
            print("  Invalid choice, try again.")


if __name__ == "__main__":
    main()