"""Tests for confidence-based [unleserlich] marker insertion."""

import os
import pytest
from confidence import apply_confidence_markers, words_from_characters, get_threshold


# ─── apply_confidence_markers ─────────────────────────────────────────────────


def test_all_words_above_threshold_passes_through():
    words = [
        {"text": "Lieber", "confidence": 0.95},
        {"text": "Freund", "confidence": 0.88},
    ]
    assert apply_confidence_markers(words) == "Lieber Freund"


def test_single_low_confidence_word_replaced():
    words = [
        {"text": "Lieber", "confidence": 0.95},
        {"text": "xkqz", "confidence": 0.1},
        {"text": "Freund", "confidence": 0.88},
    ]
    assert apply_confidence_markers(words) == "Lieber [unleserlich] Freund"


def test_adjacent_low_confidence_words_collapsed():
    words = [
        {"text": "Lieber", "confidence": 0.95},
        {"text": "xkqz", "confidence": 0.1},
        {"text": "abc", "confidence": 0.05},
        {"text": "yyy", "confidence": 0.2},
        {"text": "Freund", "confidence": 0.88},
    ]
    assert apply_confidence_markers(words) == "Lieber [unleserlich] Freund"


def test_mixed_high_low_each_group_gets_marker():
    words = [
        {"text": "Lieber", "confidence": 0.95},
        {"text": "xkqz", "confidence": 0.1},
        {"text": "wie", "confidence": 0.9},
        {"text": "abc", "confidence": 0.05},
        {"text": "dir", "confidence": 0.88},
    ]
    assert apply_confidence_markers(words) == "Lieber [unleserlich] wie [unleserlich] dir"


def test_all_below_threshold_returns_single_marker():
    words = [
        {"text": "xkq", "confidence": 0.1},
        {"text": "zzz", "confidence": 0.05},
    ]
    assert apply_confidence_markers(words) == "[unleserlich]"


def test_empty_list_returns_empty_string():
    assert apply_confidence_markers([]) == ""


def test_single_word_above_threshold():
    words = [{"text": "Hallo", "confidence": 0.9}]
    assert apply_confidence_markers(words) == "Hallo"


def test_exact_threshold_passes_through():
    """Confidence exactly at threshold should NOT be replaced (strict <)."""
    words = [{"text": "Wort", "confidence": 0.3}]
    assert apply_confidence_markers(words) == "Wort"


def test_just_below_threshold_replaced():
    words = [{"text": "Wort", "confidence": 0.29}]
    assert apply_confidence_markers(words) == "[unleserlich]"


def test_custom_threshold_via_parameter():
    words = [
        {"text": "Lieber", "confidence": 0.95},
        {"text": "Freund", "confidence": 0.5},
    ]
    assert apply_confidence_markers(words, threshold=0.8) == "Lieber [unleserlich]"
    assert apply_confidence_markers(words, threshold=0.3) == "Lieber Freund"


def test_kurrent_threshold_is_higher_than_default():
    default = get_threshold("TYPEWRITER")
    kurrent = get_threshold("HANDWRITING_KURRENT")
    assert kurrent > default


def test_get_threshold_kurrent():
    assert get_threshold("HANDWRITING_KURRENT") == 0.5


def test_get_threshold_default():
    assert get_threshold("TYPEWRITER") == 0.3
    assert get_threshold("HANDWRITING_LATIN") == 0.3
    assert get_threshold("UNKNOWN") == 0.3


def test_low_confidence_at_start():
    words = [
        {"text": "xkq", "confidence": 0.1},
        {"text": "Freund", "confidence": 0.88},
    ]
    assert apply_confidence_markers(words) == "[unleserlich] Freund"


def test_low_confidence_at_end():
    words = [
        {"text": "Lieber", "confidence": 0.95},
        {"text": "xkq", "confidence": 0.1},
    ]
    assert apply_confidence_markers(words) == "Lieber [unleserlich]"


# ─── words_from_characters ────────────────────────────────────────────────────


def test_single_word_matching_confidences():
    words = words_from_characters("Hallo", [0.9, 0.8, 0.85, 0.7, 0.95])
    assert len(words) == 1
    assert words[0]["text"] == "Hallo"
    assert abs(words[0]["confidence"] - 0.84) < 0.01


def test_multi_word_with_spaces():
    prediction = "Sehr geehrter"
    confidences = [0.9, 0.8, 0.7, 0.6, 0.5, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2]
    words = words_from_characters(prediction, confidences)
    assert len(words) == 2
    assert words[0]["text"] == "Sehr"
    assert words[1]["text"] == "geehrter"


def test_length_mismatch_falls_back_safely():
    words = words_from_characters("Hallo Welt", [0.9, 0.8])
    assert len(words) == 1
    assert words[0]["text"] == "Hallo Welt"
    assert words[0]["confidence"] == 1.0


def test_empty_prediction_returns_empty():
    assert words_from_characters("", []) == []


def test_single_character_word():
    words = words_from_characters("A B", [0.9, 0.5, 0.3])
    assert len(words) == 2
    assert words[0]["text"] == "A"
    assert words[0]["confidence"] == 0.9
    assert words[1]["text"] == "B"
    assert words[1]["confidence"] == 0.3


def test_whitespace_only_prediction():
    words = words_from_characters("   ", [0.5, 0.5, 0.5])
    assert words == []