from __future__ import annotations

import argparse
import re
import unicodedata
from pathlib import Path

import numpy as np


SENTENCE_PUNCT = "。！？.!?｡．"
ELLIPSIS_PUNCT = {"…"}
QUOTE_PUNCT = set("\"'“”‘’「」『』")


def is_text_punctuation(ch: str) -> bool:
    return ch in ELLIPSIS_PUNCT or unicodedata.category(ch).startswith("P")


def comma_for_context(left: str, right: str) -> str:
    context = left + right
    return "," if re.search(r"[A-Za-z0-9]", context) else "，"


def setup_jieba_cache(repo_dir: Path) -> None:
    import jieba

    cache_dir = repo_dir / ".work_tmp" / "jieba"
    cache_dir.mkdir(parents=True, exist_ok=True)
    jieba.dt.tmp_dir = str(cache_dir)
    jieba.dt.cache_file = "jieba.cache"


def load_text(args: argparse.Namespace) -> str:
    if args.text_file:
        text = Path(args.text_file).read_text(encoding="utf-8")
    elif args.text:
        text = args.text
    else:
        raise ValueError("Either --text or --text-file is required")
    text = re.sub(r"[ \t\r\f\v]+", " ", text)
    text = re.sub(r"\n+", " ", text)
    return text.strip()


def normalize_punctuation(text: str) -> str:
    text = re.sub(r"\s+", " ", text.strip())
    text = text.replace("……", "。").replace("...", ".")
    chars: list[str] = []
    i = 0
    while i < len(text):
        ch = text[i]
        if is_text_punctuation(ch):
            j = i
            punct_run = []
            while j < len(text) and is_text_punctuation(text[j]):
                punct_run.append(text[j])
                j += 1
            if all(p in QUOTE_PUNCT for p in punct_run):
                i = j
                continue
            sentence_marks = [p for p in punct_run if p in SENTENCE_PUNCT]
            left = chars[-1] if chars else ""
            right = text[j] if j < len(text) else ""
            mark = sentence_marks[-1] if sentence_marks else comma_for_context(left, right)
            if chars and is_text_punctuation(chars[-1]):
                chars[-1] = mark
            else:
                chars.append(mark)
            i = j
            continue
        chars.append(ch)
        i += 1

    normalized = "".join(chars)
    normalized = re.sub(r"[ \t]+([，。！？,.!?．｡])", r"\1", normalized)
    normalized = re.sub(r"([，。！？])\s+", r"\1", normalized)
    normalized = re.sub(r"([,.!?．｡])(?=[A-Za-z0-9])", r"\1 ", normalized)
    normalized = re.sub(r"\s{2,}", " ", normalized)
    normalized = re.sub(r"([，,])\s*[，,]+", r"\1", normalized)
    normalized = re.sub(r"[，,]+([。！？.!?．｡])", r"\1", normalized)
    normalized = re.sub(r"([。！？.!?．｡])([，,]+)", r"\1", normalized)
    return normalized.strip()


def join_units(left: str, right: str) -> str:
    if not left:
        return right.strip()
    right = right.strip()
    if not right:
        return left.strip()
    if re.search(r"[\u4e00-\u9fff]$", left) or re.match(r"^[\u4e00-\u9fff]", right):
        return left.rstrip() + right
    return left.rstrip() + " " + right


def split_units(text: str) -> list[str]:
    text = text.strip()
    if not text:
        return []
    pattern = r"[^。！？!?；;，,、：:\n]+[。！？!?；;，,、：:]?"
    units = [m.group(0).strip() for m in re.finditer(pattern, text) if m.group(0).strip()]
    return units or [text]


def estimate_lengths(
    prompt_frames: int,
    prompt_tokens: int,
    text_tokens: int,
    speed: float,
    max_feat_len: int,
) -> dict[str, int | bool]:
    raw_features_len = int(
        np.ceil(prompt_frames / prompt_tokens * (prompt_tokens + text_tokens) / speed)
    )
    features_len = min(raw_features_len, max_feat_len)
    generated_frames = features_len - prompt_frames
    if generated_frames <= 0:
        generated_frames = features_len
    return {
        "raw_features_len": raw_features_len,
        "features_len": features_len,
        "generated_frames": generated_frames,
        "clamped": raw_features_len > max_feat_len,
    }


def token_count(tokenizer, text: str) -> int:
    return len(tokenizer.texts_to_token_ids([text])[0])


def split_long_unit(tokenizer, unit: str, max_text_tokens: int) -> list[str]:
    if token_count(tokenizer, unit) <= max_text_tokens:
        return [unit]

    if " " in unit:
        pieces = unit.split()
        chunks: list[str] = []
        current = ""
        for piece in pieces:
            candidate = join_units(current, piece)
            if current and token_count(tokenizer, candidate) > max_text_tokens:
                chunks.append(current)
                current = piece
            else:
                current = candidate
        if current:
            chunks.append(current)
        return chunks

    chunks = []
    current = ""
    for char in unit:
        candidate = current + char
        if current and token_count(tokenizer, candidate) > max_text_tokens:
            chunks.append(current)
            current = char
        else:
            current = candidate
    if current:
        chunks.append(current)
    return chunks


def build_segments(
    tokenizer,
    text: str,
    prompt_frames: int,
    prompt_tokens_len: int,
    speed: float,
    max_feat_len: int,
    max_text_tokens: int,
    min_generated_frames: int,
    max_generated_frames: int,
    max_raw_feat_ratio: float,
) -> list[dict[str, object]]:
    raw_units = split_units(text)
    units: list[str] = []
    for unit in raw_units:
        units.extend(split_long_unit(tokenizer, unit, max_text_tokens))

    segments: list[dict[str, object]] = []
    current = ""
    for unit in units:
        candidate = join_units(current, unit)
        cand_tokens = token_count(tokenizer, candidate)
        cand_est = estimate_lengths(
            prompt_frames,
            prompt_tokens_len,
            cand_tokens,
            speed,
            max_feat_len,
        )
        raw_too_long = int(cand_est["raw_features_len"]) > int(max_feat_len * max_raw_feat_ratio)
        too_long = (
            cand_tokens > max_text_tokens
            or int(cand_est["generated_frames"]) > max_generated_frames
            or raw_too_long
        )
        if current and too_long:
            cur_tokens = token_count(tokenizer, current)
            cur_est = estimate_lengths(
                prompt_frames,
                prompt_tokens_len,
                cur_tokens,
                speed,
                max_feat_len,
            )
            segments.append({"text": current, "text_tokens": cur_tokens, **cur_est})
            current = unit
        else:
            current = candidate

    if current:
        cur_tokens = token_count(tokenizer, current)
        cur_est = estimate_lengths(
            prompt_frames,
            prompt_tokens_len,
            cur_tokens,
            speed,
            max_feat_len,
        )
        segments.append({"text": current, "text_tokens": cur_tokens, **cur_est})

    if len(segments) >= 2 and int(segments[-1]["generated_frames"]) < min_generated_frames:
        merged_text = join_units(str(segments[-2]["text"]), str(segments[-1]["text"]))
        merged_tokens = token_count(tokenizer, merged_text)
        merged_est = estimate_lengths(
            prompt_frames,
            prompt_tokens_len,
            merged_tokens,
            speed,
            max_feat_len,
        )
        raw_ok = int(merged_est["raw_features_len"]) <= int(max_feat_len * max_raw_feat_ratio)
        if (
            merged_tokens <= max_text_tokens
            and int(merged_est["generated_frames"]) <= max_generated_frames
            and raw_ok
        ):
            segments[-2] = {"text": merged_text, "text_tokens": merged_tokens, **merged_est}
            segments.pop()
        else:
            rebalanced = rebalance_short_tail(
                tokenizer,
                str(segments[-2]["text"]),
                str(segments[-1]["text"]),
                prompt_frames,
                prompt_tokens_len,
                speed,
                max_feat_len,
                max_text_tokens,
                min_generated_frames,
                max_generated_frames,
                max_raw_feat_ratio,
            )
            if rebalanced is not None:
                segments[-2], segments[-1] = rebalanced

    return segments


def split_rebalance_pieces(text: str) -> list[str]:
    units = split_units(text)
    if len(units) > 1:
        return units
    if " " in text:
        return text.split()
    return list(text)


def segment_record(
    tokenizer,
    text: str,
    prompt_frames: int,
    prompt_tokens_len: int,
    speed: float,
    max_feat_len: int,
) -> dict[str, object]:
    text_tokens = token_count(tokenizer, text)
    est = estimate_lengths(
        prompt_frames,
        prompt_tokens_len,
        text_tokens,
        speed,
        max_feat_len,
    )
    return {"text": text, "text_tokens": text_tokens, **est}


def segment_within_limits(
    record: dict[str, object],
    max_text_tokens: int,
    max_generated_frames: int,
    max_raw_feat: int,
) -> bool:
    return (
        int(record["text_tokens"]) <= max_text_tokens
        and int(record["generated_frames"]) <= max_generated_frames
        and int(record["raw_features_len"]) <= max_raw_feat
    )


def rebalance_short_tail(
    tokenizer,
    prev_text: str,
    tail_text: str,
    prompt_frames: int,
    prompt_tokens_len: int,
    speed: float,
    max_feat_len: int,
    max_text_tokens: int,
    min_generated_frames: int,
    max_generated_frames: int,
    max_raw_feat_ratio: float,
) -> tuple[dict[str, object], dict[str, object]] | None:
    max_raw_feat = int(max_feat_len * max_raw_feat_ratio)
    best: tuple[dict[str, object], dict[str, object]] | None = None
    best_tail_frames = -1

    piece_sets = [split_rebalance_pieces(prev_text)]
    if " " in prev_text:
        word_pieces = prev_text.split()
        if len(word_pieces) > 1 and word_pieces != piece_sets[0]:
            piece_sets.append(word_pieces)

    for pieces in piece_sets:
        if len(pieces) < 2:
            continue
        for split_at in range(len(pieces) - 1, 0, -1):
            new_prev = (
                join_units("", " ".join(pieces[:split_at]))
                if " " in prev_text
                else "".join(pieces[:split_at])
            )
            moved_tail = (
                join_units("", " ".join(pieces[split_at:]))
                if " " in prev_text
                else "".join(pieces[split_at:])
            )
            new_tail = join_units(moved_tail, tail_text)
            prev_record = segment_record(
                tokenizer,
                new_prev,
                prompt_frames,
                prompt_tokens_len,
                speed,
                max_feat_len,
            )
            tail_record = segment_record(
                tokenizer,
                new_tail,
                prompt_frames,
                prompt_tokens_len,
                speed,
                max_feat_len,
            )
            if not segment_within_limits(
                tail_record,
                max_text_tokens,
                max_generated_frames,
                max_raw_feat,
            ):
                continue
            if not segment_within_limits(
                prev_record,
                max_text_tokens,
                max_generated_frames,
                max_raw_feat,
            ):
                continue
            prev_frames = int(prev_record["generated_frames"])
            tail_frames = int(tail_record["generated_frames"])
            if prev_frames < min_generated_frames:
                continue
            if tail_frames > best_tail_frames:
                best = (prev_record, tail_record)
                best_tail_frames = tail_frames
            if tail_frames >= min_generated_frames:
                return best

    return best


def build_cat_tokens(tokenizer, prompt_tokens: list[int], text_tokens: list[int], max_tokens: int) -> np.ndarray:
    pad_id = tokenizer.pad_id
    cat = prompt_tokens + text_tokens + [pad_id]
    cat_tokens = np.full((1, max_tokens), pad_id, dtype=np.int64)
    cat_tokens[0, : len(cat)] = np.array(cat, dtype=np.int64)
    return cat_tokens