import re
from pathlib import Path

from copienator import EvaluationWorkspace
from .platform import validate_windows_labels

def natural_key(text):
    return [int(c) if c.isdigit() else c.lower() for c in re.split(r'(\d+)', str(text))]

def read_all_labels(base_dir):
    labels = EvaluationWorkspace(Path(base_dir)).read_labels()
    validate_windows_labels(labels)
    return labels

def enonce_total(base_dir):
    text_dir = Path(base_dir) / 'Text'
    if not text_dir.is_dir():
        return ""

    files = [f for f in text_dir.iterdir() if f.is_file() and f.suffix not in [".pdf", ".tex"]]
    files.sort(key=lambda f: natural_key(f.name))

    output = []
    for filepath in files:
        content = filepath.read_text(encoding='utf-8')
        output.append(f"{filepath.name}\n{content}\n\n\n")

    return "".join(output)

import os
import shlex

from .platform import open_path

def edit_file_and_enter(file):
    editor = os.environ.get("EDITOR")
    try:
        if editor:
            subprocess.run(shlex.split(editor, posix=os.name != "nt") + [str(file)])
        else:
            open_path(file)
        input("Press ENTER here once you have saved and closed the text file...")
    except Exception as e:
        print(f"Error running editor: {e}")


def pdf_image_of_enonce(root_dir, label):
    pdf_path = os.path.join(root_dir, "Text2", f"{label}.pdf")
    if os.path.exists(pdf_path):
        return pdf_path

def pdf_image_of_solution(root_dir, label):
    pdf_path = os.path.join(root_dir, "Sol2", f"{label}.pdf")
    if os.path.exists(pdf_path):
        return pdf_path

def pdf_images_of_contexts(root_dir, label, all_labels):
    text2_dir = os.path.join(root_dir, "Text2")
    if not os.path.isdir(text2_dir):
        return []

    # Map safe labels (with '/' replaced by '_') to their chronological index
    safe_to_idx = {l.replace("/", "_"): i for i, l in enumerate(all_labels)}

    safe_target = label.replace("/", "_")
    target_idx = safe_to_idx.get(safe_target, -1)

    if target_idx == -1:
        return []

    pertinent_contexts = []

    for filename in os.listdir(text2_dir):
        if filename.startswith("CTXT ") and filename.endswith(".pdf"):
            # Extract "first_label -> last_label" from "CTXT first_label -> last_label.pdf"
            core = filename[5:-4]
            parts = core.split(" -> ")

            if len(parts) == 2:
                first_safe, last_safe = parts
                first_idx = safe_to_idx.get(first_safe, -1)
                last_idx = safe_to_idx.get(last_safe, -1)

                # Check if the current label falls within the context's validity range
                if first_idx != -1 and last_idx != -1:
                    if first_idx <= target_idx <= last_idx:
                        pdf_path = os.path.join(text2_dir, filename)
                        pertinent_contexts.append((first_idx, pdf_path))

    # Sort by first_idx to ensure contexts are returned in logical reading order
    pertinent_contexts.sort(key=lambda x: x[0])
    return [path for _, path in pertinent_contexts]


def get_exam_file_content(folder_path, mode, label):
    """
    Retrieves content from the Text or Sol directory for a specific label.
    Checks for exact filename matches or grouped 'prefix[a,b,c]' filenames.
    """
    target_dir = Path(folder_path) / mode
    if not target_dir.is_dir():
        return None

    # Sanitize label (consistent with the script's saving logic)
    safe_label = label.replace("/", "_")

    # 1. Try exact filename match
    direct_file = target_dir / safe_label
    if direct_file.is_file():
        return direct_file.read_text(encoding="utf-8")

    # 2. Search for grouped files: prefix[suffix1,suffix2,...]
    for file_path in target_dir.iterdir():
        if not file_path.is_file():
            continue
        name = file_path.name
        if "[" in name and name.endswith("]"):
            # Split 'prefix[suffixes]' -> 'prefix', 'suffixes'
            prefix, rest = name.split("[", 1)
            suffixes = rest[:-1].split(",") # Remove trailing ']' and split

            # Check if any reconstructed label matches
            for s in suffixes:
                if (prefix + s) == safe_label:
                    return file_path.read_text(encoding="utf-8")

    return None

def get_label_text_content(folder, label):
    return get_exam_file_content(folder, "Text", label)

def get_label_sol_content(folder, label):
    return get_exam_file_content(folder, "Sol", label)

def get_label_persp_content(folder, label):
    return get_exam_file_content(folder, "Persp", label)

import tempfile
import shutil
import subprocess

from .configuration import LATEX_AFTER, LATEX_BEFORE

LATEX_WARNING_MARKER = "[Copienator:latex-warning] "


def report_latex_warning(output_pdf_path) -> None:
    """Emit a stable, machine-readable path alongside human diagnostics."""
    print(f"{LATEX_WARNING_MARKER}{Path(output_pdf_path).resolve()}")


def fragment_latex_header(source_path=None):
    """Keep source packages/macros while using the configured fragment layout."""
    if source_path is None:
        return LATEX_BEFORE
    source = Path(source_path).read_text(encoding="utf-8")
    # Ignore commented document commands when locating the preamble.
    source = re.sub(r"(?m)(?<!\\)%[^\n]*", "", source)
    begin = re.search(r"\\begin\s*\{document\}", source)
    document_class = r"\\documentclass(?:\s*\[[^\]]*\])?\s*\{[^}]+\}"
    configured_class = re.search(document_class, LATEX_BEFORE)
    configured_begin = re.search(r"\\begin\s*\{document\}", LATEX_BEFORE)
    if begin is None or configured_class is None or configured_begin is None:
        return LATEX_BEFORE
    preamble = source[:begin.start()]
    if not re.search(document_class, preamble):
        return LATEX_BEFORE
    preamble = re.sub(document_class, lambda _: configured_class.group(), preamble, count=1)
    # geometry overrides standalone's crop coordinates and can produce blank or
    # clipped PDFs even when LaTeX succeeds. Keep other source packages intact.
    def without_geometry(match):
        packages = [name.strip() for name in match.group(2).split(',')
                    if name.strip() != 'geometry']
        return (r'\usepackage' + (match.group(1) or '') + '{' + ','.join(packages) + '}'
                if packages else '')
    preamble = re.sub(r'\\usepackage\s*(\[[^\]]*\])?\s*\{([^}]+)\}',
                      without_geometry, preamble)
    preamble = re.sub(r'\\(?:geometry|newgeometry)\s*\{[^}]*\}', '', preamble)
    return preamble + LATEX_BEFORE[configured_begin.start():]


def compile_to_pdf(text, output_pdf_path, *, strict=False, source_path=None):
    """Wraps text in standalone header/footer templates and compiles it to PDF."""
    latex_template = f"{fragment_latex_header(source_path)}{text}{LATEX_AFTER}"
    env = os.environ.copy()
    if source_path is not None:
        source_dir = str(Path(source_path).resolve().parent)
        env['TEXINPUTS'] = source_dir + os.pathsep + env.get('TEXINPUTS', '')

    with tempfile.TemporaryDirectory() as temp_dir:
        tex_filename = 'text.tex'
        pdf_filename = 'text.pdf'
        tex_path = os.path.join(temp_dir, tex_filename)

        with open(tex_path, 'w', encoding='utf-8') as f:
            f.write(latex_template)

        # Set TEXINPUTS so pdflatex can find commands.sty if it's in the current dir
        # env = os.environ.copy()
        # current_dir = os.getcwd()
        # env['TEXINPUTS'] = f".:{current_dir}:"

        try:
            result = subprocess.run(
                ['pdflatex', '-interaction=nonstopmode', tex_filename],
                cwd=temp_dir,
                env=env,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT,
                text=True,
                encoding="utf-8", errors="replace",
                check=False
            )
            if "minted" in text:
                result = subprocess.run(
                    ['pdflatex', '-interaction=nonstopmode', tex_filename],
                    cwd=temp_dir,
                    env=env,
                    stdout=subprocess.PIPE,
                    stderr=subprocess.STDOUT,
                    text=True,
                    encoding="utf-8", errors="replace",
                    check=False)

            generated_pdf = os.path.join(temp_dir, pdf_filename)
            pdf_generated = os.path.exists(generated_pdf)
            if pdf_generated and (not strict or result.returncode == 0):
                shutil.move(generated_pdf, output_pdf_path)

            if result.returncode != 0:
                report_latex_warning(output_pdf_path)
                lines = result.stdout.splitlines()
                first = next((i for i, line in enumerate(lines) if line.lstrip().startswith("!")), None)
                detail = "\n" + "\n".join(lines[first:first + 5]) if first is not None else ""
                pdf_status = "a PDF was generated" if pdf_generated else "no PDF was generated"
                print(
                    f"Warning: LaTeX compilation reported errors for {output_pdf_path} "
                    f"(exit code {result.returncode}; {pdf_status}){detail}"
                )
                if strict:
                    raise RuntimeError(f"LaTeX failed for {output_pdf_path}{detail}")
            elif not pdf_generated:
                report_latex_warning(output_pdf_path)
                print(f"Warning: LaTeX compilation produced no PDF for {output_pdf_path}")
                if strict:
                    raise RuntimeError(f"No PDF generated for {output_pdf_path}")
        except Exception as e:
            if strict:
                raise
            report_latex_warning(output_pdf_path)
            print(f"Compilation error for {output_pdf_path}: {e}")