"""Regression tests for large composer text paste attachment behavior."""
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
BOOT_JS = (ROOT / "static" / "boot.js").read_text(encoding="utf-8")
CHANGELOG = (ROOT / "CHANGELOG.md").read_text(encoding="utf-8")
I18N_JS = (ROOT / "static" / "i18n.js").read_text(encoding="utf-8")


def test_large_text_paste_threshold_helpers_are_defined():
    assert "const LARGE_TEXT_PASTE_CHAR_THRESHOLD=4000" in BOOT_JS
    assert "const LARGE_TEXT_PASTE_LINE_THRESHOLD=100" in BOOT_JS
    assert "function _shouldAttachLargePastedText(text)" in BOOT_JS
    assert "value.length>=LARGE_TEXT_PASTE_CHAR_THRESHOLD" in BOOT_JS
    assert "_largeTextPasteLineCount(value)>=LARGE_TEXT_PASTE_LINE_THRESHOLD" in BOOT_JS


def test_large_text_line_count_does_not_overcount_trailing_newline():
    assert "const lines=value.split('\\n');" in BOOT_JS
    assert "return value.endsWith('\\n')?lines.length-1:lines.length;" in BOOT_JS


def test_line_threshold_is_one_hundred_lines():
    assert "const LARGE_TEXT_PASTE_LINE_THRESHOLD=100" in BOOT_JS
    assert "_largeTextPasteLineCount(value)>=LARGE_TEXT_PASTE_LINE_THRESHOLD" in BOOT_JS


def test_large_text_paste_creates_markdown_file_and_uses_existing_tray():
    assert "function _largeTextPasteFile(text,now)" in BOOT_JS
    assert "function _attachLargePastedText(file)" in BOOT_JS
    assert "pasted-text-${stamp}.md" in BOOT_JS
    assert "const existing=new Set((S.pendingFiles||[]).map(f=>f&&f.name).filter(Boolean))" in BOOT_JS
    assert "for(let i=2;existing.has(name);i++)name=`pasted-text-${stamp}-${i}.md`;" in BOOT_JS
    assert "new File([String(text||'')],name,{type:'text/markdown;charset=utf-8'})" in BOOT_JS
    assert "addFiles([file])" in BOOT_JS
    assert "setStatus(t('text_pasted')+file.name)" in BOOT_JS


def test_large_text_status_uses_i18n_key_available_to_all_locales():
    assert "text_pasted: 'Pasted text attached as '," in I18N_JS
    assert I18N_JS.count("text_pasted:") == I18N_JS.count("image_pasted:")


def test_paste_handler_keeps_image_paste_path_before_large_text_path():
    paste_idx = BOOT_JS.index("$('msg').addEventListener('paste',e=>{")
    image_idx = BOOT_JS.index("if(imageItems.length){", paste_idx)
    return_idx = BOOT_JS.index("return;", image_idx)
    text_idx = BOOT_JS.index("const plainText=e.clipboardData?.getData('text/plain')||'';", paste_idx)
    attach_idx = BOOT_JS.index("_attachLargePastedText(pastedTextFile);", text_idx)

    assert image_idx < return_idx < text_idx < attach_idx
    assert "if(!hasText)e.preventDefault();" in BOOT_JS[image_idx:return_idx]


def test_large_text_paste_prevents_default_textarea_insert_only_for_large_plain_text():
    text_idx = BOOT_JS.index("const plainText=e.clipboardData?.getData('text/plain')||'';")
    block = BOOT_JS[text_idx : BOOT_JS.index("});", text_idx)]
    assert "if(!_shouldAttachLargePastedText(plainText))return;" in block
    assert "const pastedTextFile=_largeTextPasteFile(plainText);" in block
    assert "if(!_largeTextPasteFitsUploadLimit(pastedTextFile))return;" in block
    assert "e.preventDefault();" in block
    assert "_attachLargePastedText(pastedTextFile);" in block
    assert block.index("if(!_shouldAttachLargePastedText(plainText))return;") < block.index("const pastedTextFile=_largeTextPasteFile(plainText);")
    assert block.index("if(!_largeTextPasteFitsUploadLimit(pastedTextFile))return;") < block.index("e.preventDefault();")


def test_oversize_large_text_paste_falls_back_to_native_paste_instead_of_being_dropped():
    assert "function _largeTextPasteFitsUploadLimit(file)" in BOOT_JS
    assert "typeof MAX_UPLOAD_BYTES==='number'&&file.size>MAX_UPLOAD_BYTES" in BOOT_JS
    text_idx = BOOT_JS.index("const plainText=e.clipboardData?.getData('text/plain')||'';")
    block = BOOT_JS[text_idx : BOOT_JS.index("});", text_idx)]
    fit_idx = block.index("if(!_largeTextPasteFitsUploadLimit(pastedTextFile))return;")
    prevent_idx = block.index("e.preventDefault();")
    attach_idx = block.index("_attachLargePastedText(pastedTextFile);")
    assert fit_idx < prevent_idx < attach_idx


def test_changelog_mentions_large_text_paste_attachment():
    assert "Large plain-text pastes in the composer now become `.md` attachments" in CHANGELOG