import os
import re
import json
import csv
import pathlib
from typing import List, Dict, Any
from .schemas import BenchmarkTask

def detect_language(text: str) -> str:
    # Arabic if contains Arabic unicode
    if re.search(r'[\u0600-\u06FF]', text):
        return "ar"
    return "en"

def infer_category(prompt: str, language: str) -> str:
    low = prompt.lower()
    # Coding indicators
    code_kw = ["def ", "function", "code", "كود", "python", "for ", "while ", "class ", "import ", "return"]
    if any(k in low for k in code_kw) or "```" in prompt:
        return "coding"
    # Summarization
    sum_kw = ["summarize", "تلخيص", "لخص", "summary", "خلاصة"]
    if any(k in low for k in sum_kw):
        return "summarization"
    # Reasoning
    reason_kw = ["reason", "logic", "منطق", "احسب", "calculate", "if ", "كم ", "ما هو", "why", "because"]
    if any(k in low for k in reason_kw):
        return "reasoning"
    # Fallback by language
    if language == "ar":
        return "arabic"
    return "reasoning"

def parse_csv_file(path: pathlib.Path) -> List[Dict[str, Any]]:
    rows = []
    with open(path, 'r', encoding='utf-8-sig', newline='') as f:
        # Use sniff
        try:
            dialect = csv.Sniffer().sniff(f.read(2048))
            f.seek(0)
        except:
            f.seek(0)
            dialect = csv.excel
        reader = csv.DictReader(f, dialect=dialect)
        # If no header, treat as plain
        if reader.fieldnames is None:
            f.seek(0)
            reader = csv.reader(f)
            for i, row in enumerate(reader):
                if not row or not row[0].strip():
                    continue
                rows.append({"prompt": row[0], "expected": row[1] if len(row)>1 else None, "category": row[2] if len(row)>2 else None})
            return rows
        # Normalize fieldnames lower
        lower_fields = [h.lower().strip() for h in reader.fieldnames] if reader.fieldnames else []
        # Map possible headers
        prompt_keys = ["prompt", "question", "input", "text", "السؤال", "النص"]
        expected_keys = ["expected", "answer", "target", "expected_answer", "الإجابة", "الجواب"]
        regex_keys = ["expected_regex", "regex", "pattern"]
        cat_keys = ["category", "cat", "type", "الفئة"]
        name_keys = ["name", "title", "id"]
        for row in reader:
            # lower keys dict
            low_row = {k.lower().strip(): v for k,v in row.items() if k}
            prompt = None
            for k in prompt_keys:
                if k in low_row and low_row[k]:
                    prompt = low_row[k]
                    break
            if not prompt:
                # fallback first column
                prompt = next((v for v in row.values() if v), None)
            if not prompt or not prompt.strip():
                continue
            expected = None
            for k in expected_keys:
                if k in low_row and low_row[k]:
                    expected = low_row[k]
                    break
            expected_regex = None
            for k in regex_keys:
                if k in low_row and low_row[k]:
                    expected_regex = low_row[k]
                    break
            category = None
            for k in cat_keys:
                if k in low_row and low_row[k]:
                    category = low_row[k].lower().strip()
                    break
            name = None
            for k in name_keys:
                if k in low_row and low_row[k]:
                    name = low_row[k]
                    break
            rows.append({"prompt": prompt.strip(), "expected": expected.strip() if expected else None, "expected_regex": expected_regex.strip() if expected_regex else None, "category": category, "name": name})
    return rows

def parse_json_file(path: pathlib.Path) -> List[Dict[str, Any]]:
    with open(path, 'r', encoding='utf-8') as f:
        data = json.load(f)
    # Handle various wrappers
    if isinstance(data, dict):
        # Look for list inside
        for key in ["data", "tasks", "items", "dataset", "examples"]:
            if key in data and isinstance(data[key], list):
                data = data[key]
                break
        else:
            # Single object
            data = [data]
    if not isinstance(data, list):
        raise ValueError("JSON must be list or dict with list")
    rows = []
    for item in data:
        if not isinstance(item, dict):
            continue
        # Map keys case-insensitive
        low = {k.lower(): v for k,v in item.items()}
        prompt = low.get("prompt") or low.get("question") or low.get("input") or low.get("text") or low.get("instruction")
        expected = low.get("expected") or low.get("answer") or low.get("target") or low.get("output")
        expected_regex = low.get("expected_regex") or low.get("regex") or low.get("pattern")
        category = low.get("category") or low.get("cat") or low.get("type")
        name = low.get("name") or low.get("title") or low.get("id")
        if prompt:
            rows.append({"prompt": str(prompt), "expected": str(expected) if expected else None, "expected_regex": str(expected_regex) if expected_regex else None, "category": str(category).lower() if category else None, "name": str(name) if name else None})
    return rows

def parse_jsonl_file(path: pathlib.Path) -> List[Dict[str, Any]]:
    rows = []
    with open(path, 'r', encoding='utf-8') as f:
        for line in f:
            line=line.strip()
            if not line:
                continue
            try:
                obj = json.loads(line)
                low = {k.lower(): v for k,v in obj.items()} if isinstance(obj, dict) else {}
                prompt = low.get("prompt") or low.get("question") or low.get("input") or low.get("text")
                expected = low.get("expected") or low.get("answer")
                expected_regex = low.get("expected_regex") or low.get("regex")
                category = low.get("category")
                name = low.get("name") or low.get("id")
                if prompt:
                    rows.append({"prompt": str(prompt), "expected": str(expected) if expected else None, "expected_regex": str(expected_regex) if expected_regex else None, "category": str(category).lower() if category else None, "name": str(name) if name else None})
            except json.JSONDecodeError:
                # Treat line as prompt|expected
                if "|" in line:
                    parts = line.split("|",1)
                    rows.append({"prompt": parts[0].strip(), "expected": parts[1].strip(), "expected_regex": None, "category": None, "name": None})
                elif "\t" in line:
                    parts = line.split("\t",1)
                    rows.append({"prompt": parts[0].strip(), "expected": parts[1].strip() if len(parts)>1 else None, "expected_regex": None, "category": None, "name": None})
                else:
                    rows.append({"prompt": line, "expected": None, "expected_regex": None, "category": None, "name": None})
    return rows

def parse_txt_file(path: pathlib.Path) -> List[Dict[str, Any]]:
    rows=[]
    with open(path, 'r', encoding='utf-8', errors='ignore') as f:
        for line in f:
            line=line.strip()
            if not line or line.startswith("#"):
                continue
            # Support prompt|expected or prompt<TAB>expected
            if "|" in line:
                p,e = line.split("|",1)
                rows.append({"prompt": p.strip(), "expected": e.strip(), "expected_regex": None, "category": None, "name": None})
            elif "\t" in line:
                p,e = line.split("\t",1)
                rows.append({"prompt": p.strip(), "expected": e.strip(), "category": None, "expected_regex": None, "name": None})
            else:
                rows.append({"prompt": line, "expected": None, "expected_regex": None, "category": None, "name": None})
    return rows

def parse_file(path: pathlib.Path) -> List[Dict[str, Any]]:
    ext = path.suffix.lower()
    if ext == ".csv":
        return parse_csv_file(path)
    elif ext == ".json":
        return parse_json_file(path)
    elif ext == ".jsonl":
        return parse_jsonl_file(path)
    elif ext in [".txt", ".text", ".dat"]:
        return parse_txt_file(path)
    elif ext in [".md"]:
        return parse_txt_file(path)
    else:
        # Try json, then txt
        try:
            return parse_json_file(path)
        except:
            try:
                return parse_jsonl_file(path)
            except:
                return parse_txt_file(path)

def scan_folder(folder: pathlib.Path) -> Dict[str, Any]:
    if not folder.exists() or not folder.is_dir():
        raise FileNotFoundError(f"المجلد غير موجود: {folder}")
    supported = {".csv",".json",".jsonl",".txt",".md"}
    files = [p for p in folder.rglob("*") if p.is_file() and p.suffix.lower() in supported]
    # Also include .txt without suffix? already
    all_rows = []
    per_file = {}
    language_counts = {"ar":0, "en":0}
    for fp in files:
        try:
            rows = parse_file(fp)
            per_file[str(fp.relative_to(folder))] = len(rows)
            for r in rows:
                lang = detect_language(r["prompt"])
                language_counts[lang]+=1
                # Auto fill missing fields
                if not r.get("category"):
                    r["category"] = infer_category(r["prompt"], lang)
                # Normalize category
                cat = r["category"].lower().strip()
                if cat not in ["reasoning","coding","arabic","summarization"]:
                    # Map arabic synonyms
                    if cat in ["ar","arabic_quality","عربي"]:
                        cat="arabic"
                    elif cat in ["code","برمجة"]:
                        cat="coding"
                    elif cat in ["reason","منطق"]:
                        cat="reasoning"
                    else:
                        # keep inferred
                        cat = infer_category(r["prompt"], lang)
                    r["category"]=cat
                # Auto regex if missing and expected exists: escape expected as regex
                if not r.get("expected_regex") and r.get("expected"):
                    # Simple word boundary regex
                    exp = r["expected"].strip()
                    # Escape but keep simple
                    r["expected_regex"] = re.escape(exp[:40])
                    # For Arabic, keep as is
                    if lang=="ar":
                        r["expected_regex"] = exp[:40]
                # Name fallback
                if not r.get("name"):
                    r["name"] = f"{r['category']}-{len(all_rows)+1}"
                r["language"] = lang
                r["source_file"] = str(fp.name)
            all_rows.extend(rows)
        except Exception as e:
            per_file[str(fp.relative_to(folder))] = f"error: {e}"
    return {
        "folder": str(folder),
        "files_found": len(files),
        "per_file_counts": per_file,
        "total_tasks": len(all_rows),
        "language_counts": language_counts,
        "rows": all_rows
    }

def rows_to_tasks(rows: List[Dict[str, Any]]) -> List[BenchmarkTask]:
    tasks = []
    for i, r in enumerate(rows):
        prompt = r["prompt"]
        expected = r.get("expected")
        expected_regex = r.get("expected_regex")
        cat = r.get("category", "reasoning")
        name = r.get("name") or f"custom-{i+1}"
        # Ensure valid category
        if cat not in ["reasoning","coding","arabic","summarization"]:
            cat="reasoning"
        lang = r.get("language") or detect_language(prompt)
        # Auto adjust max_tokens by category
        max_tokens = 256
        if cat=="coding":
            max_tokens=300
        elif cat=="summarization":
            max_tokens=200
        tasks.append(BenchmarkTask(
            id=f"custom-{i+1:04d}",
            name=name,
            category=cat,
            prompt=prompt,
            expected=expected,
            expected_regex=expected_regex,
            max_tokens=max_tokens
        ))
    return tasks