"""
VoiceNote AI - Utilities
WER calculation, VIPS formatting, evaluation export
"""

import json
import logging
from datetime import datetime
from config import Config

logger = logging.getLogger(__name__)


def calculate_wer(reference: str, hypothesis: str) -> float:
    """
    Calculate Word Error Rate (WER).

    WER = (Substitutions + Deletions + Insertions) / N
    where N = total words in reference.

    Args:
        reference: Ground truth transcription
        hypothesis: Whisper output

    Returns:
        WER as percentage (0–100). Returns 0.0 if reference is empty.
    """
    if not reference or not reference.strip():
        return 0.0

    ref_words = reference.strip().lower().split()
    hyp_words = hypothesis.strip().lower().split()

    # Dynamic programming edit distance
    d = [[0] * (len(hyp_words) + 1) for _ in range(len(ref_words) + 1)]
    for i in range(len(ref_words) + 1):
        d[i][0] = i
    for j in range(len(hyp_words) + 1):
        d[0][j] = j

    for i in range(1, len(ref_words) + 1):
        for j in range(1, len(hyp_words) + 1):
            if ref_words[i - 1] == hyp_words[j - 1]:
                d[i][j] = d[i - 1][j - 1]
            else:
                d[i][j] = 1 + min(d[i - 1][j - 1], d[i][j - 1], d[i - 1][j])

    wer = (d[len(ref_words)][len(hyp_words)] / len(ref_words)) * 100
    return round(wer, 2)


def format_vips_output(vips: dict) -> str:
    """Format a VIPS dict as readable Swedish clinical text."""
    labels = {
        "V": "V (Välbefinnande)",
        "I": "I (Integritet)",
        "P": "P (Prevention)",
        "S": "S (Säkerhet)",
    }
    lines = [f"{labels.get(k, k)}: {vips.get(k, 'Ingen relevant information.')}"
             for k in ["V", "I", "P", "S"]]
    return "\n".join(lines)


def save_evaluation(entry: dict) -> str:
    """
    Append an evaluation entry to the JSONL file.

    Args:
        entry: Dict with evaluation answers

    Returns:
        Status message
    """
    entry["timestamp"] = datetime.utcnow().isoformat() + "Z"
    try:
        with open(Config.EVAL_FILE, "a", encoding="utf-8") as f:
            f.write(json.dumps(entry, ensure_ascii=False) + "\n")
        logger.info(f"Evaluation saved: {entry}")
        return "✅ Utvärdering sparad!"
    except Exception as e:
        logger.error(f"Failed to save evaluation: {e}")
        return f"⚠️ Kunde inte spara: {e}"


def format_timestamp() -> str:
    return datetime.now().strftime("%H:%M:%S")