"""Preserve the inherited prompt skeleton and inject measured score slots.

Only the global caption and the leading sentence-cue parentheses are replaced
in score mode. The inherited template repeats the SCRIPT in Instruction and
Text; both copies map to the same measured local feature bank.
"""
import re
import sys
from pathlib import Path
import numpy as np
import torch
from conditioning import MARKERS, feature_vector, install_markers

sys.path.insert(0, '/e/scratch/reformo/schuhmann1_moss/code/small_tts')
from pack_moss import MossPacker
from prompt_fmt import user_content

GLOBAL_BLOCK = MARKERS[0] + MARKERS[1] * 5 + MARKERS[2]
LOCAL_BLOCK = MARKERS[3] + MARKERS[4] * 10 + MARKERS[5]


def score_prompt(prompt, sentence_count):
    if not prompt.startswith('GENERAL: ') or '\nSCRIPT:\n' not in prompt:
        raise ValueError('Score mode requires the verified GENERAL/SCRIPT prompt format')
    _, script = prompt.split('\nSCRIPT:\n', 1)
    lines = script.splitlines()
    if len(lines) != sentence_count or not lines:
        raise ValueError(f'Prompt cues and measured sentence rows disagree: {len(lines)} vs {sentence_count}')
    edited, bodies = [], []
    for line in lines:
        match = re.match(r'^\([^)]*\)(.*)$', line)
        if not match:
            raise ValueError('Expected one leading parenthesized sentence cue')
        body = match.group(1)
        bodies.append(body)
        edited.append(LOCAL_BLOCK + body)
    changed = 'GENERAL: ' + GLOBAL_BLOCK + '\nSCRIPT:\n' + '\n'.join(edited)
    # Everything following the cue stays byte-identical, including burst tags,
    # pause spellings, numbers and punctuation. Durations live in the template.
    assert all(new[len(LOCAL_BLOCK):] == old for new, old in zip(edited, bodies))
    return changed


def labels_for(ids, assist, aend, audio_pad):
    labels = torch.full_like(ids, -100)
    labels[:-1] = ids[1:]
    targets = labels[:, 0]
    supervised = targets.eq(assist) | targets.eq(aend)
    first = ids[:, 0].eq(assist).nonzero()
    if not first.numel():
        raise ValueError('No assistant target frames in the packed training example')
    supervised[:max(0, int(first[0]) - 1)] = False
    labels[~supervised] = -100
    audio = labels[:, 1:]
    audio[(audio >= audio_pad) | (audio < 0)] = -100
    return labels


def generated_audio(result, config):
    """MOSS generate returns BOA + 13-channel rows, not a [frames,12] array.

    Follow the already validated M1/M2 evaluator's extraction. Any unexpected
    remaining code value is an error rather than silently clipping corruption.
    """
    start_length, sequence = result[0]
    assert start_length == 0, 'This continuation path requires an empty target prefix'
    assert sequence.ndim == 2 and sequence.shape[1] == int(config.n_vq) + 1
    assert int(sequence[0, 0]) == int(config.audio_start_token_id)
    audio = sequence[1:, 1:]
    keep = (audio[:, 0] != int(config.audio_pad_token_id)) & (audio[:, 0] >= 0)
    audio = audio[keep]
    if audio.numel():
        assert int(audio.min()) >= 0 and int(audio.max()) < int(config.audio_pad_token_id)
    return audio


class ScorePacker(MossPacker):
    def __init__(self, proc, config, schema):
        super().__init__(proc, config)
        self.schema = schema
        self.markers = install_markers(proc.tokenizer, int(config.vocab_size))

    def _prepare(self, meta, mode, ref_codes):
        if mode not in ('instruction', 'reference', 'score'):
            raise ValueError(mode)
        if (ref_codes is not None) != (mode == 'reference'):
            raise ValueError('Reference mode must have a genuine non-target reference')
        record = dict(meta)
        global_values = [0.] * (2 * len(self.schema['global_dimensions']))
        local_values = []
        if mode == 'score':
            measurements = meta['conditioning_measurements']
            if not measurements.get('validated'):
                raise ValueError('Score mode requires independently validated measurement provenance')
            local = measurements['sentences']
            record['prompt'] = score_prompt(meta['prompt'], len(local))
            global_values = feature_vector(measurements['global'], self.schema['global_dimensions'])
            for row in local:
                if row['scope'] not in ('sentence_audio', 'whole_target_single_cue_rescored', 'windowed_sentence_audio') or not row.get('provenance'):
                    raise ValueError('Whole-clip or unknown measurements cannot populate local score slots')
                local_values.append(feature_vector(row['values'], self.schema['local_dimensions']))
            if not local_values:
                raise ValueError('No local measurements for score mode')
        return record, global_values, local_values

    def _index(self, ids, mode, sentence_count):
        index = torch.zeros(ids.shape[0], dtype=torch.long)
        text = ids[:, 0].tolist()
        global_start = self.markers[MARKERS[0]]
        local_start = self.markers[MARKERS[3]]
        gs = [i for i, token in enumerate(text) if token == global_start]
        ls = [i for i, token in enumerate(text) if token == local_start]
        if mode != 'score':
            if gs or ls:
                raise ValueError('Score markers unexpectedly present outside score mode')
            return index
        if len(gs) != 1 or len(ls) != 2 * sentence_count:
            raise ValueError(f'Unexpected template score-block coverage: global={len(gs)}, sentence={len(ls)}')
        expect_global = [global_start] + [self.markers[MARKERS[1]]] * 5 + [self.markers[MARKERS[2]]]
        expect_local = [local_start] + [self.markers[MARKERS[4]]] * 10 + [self.markers[MARKERS[5]]]
        i = gs[0]
        assert text[i:i + 7] == expect_global
        index[i:i + 7] = torch.arange(1, 8)
        for repeat, i in enumerate(ls):
            assert text[i:i + 12] == expect_local
            base = 8 + (repeat % sentence_count) * 12
            index[i:i + 12] = torch.arange(base, base + 12)
        return index

    def pack_mode(self, meta, codes, mode, ref_codes=None, generation=False):
        record, glob, local = self._prepare(meta, mode, ref_codes)
        content = user_content(record, mode == 'reference')
        user = {'role': 'user', 'content': content,
                'audio_codes_list': [torch.as_tensor(np.asarray(ref_codes).copy(), dtype=torch.long)] if ref_codes is not None else []}
        conversation = [user]
        if not generation:
            conversation.append(self.proc.build_assistant_message(audio_codes_list=[torch.as_tensor(np.asarray(codes), dtype=torch.long)]))
        packed = self.proc([conversation], mode='generation' if generation else 'computing_loss')
        ids = packed['input_ids'][0].long()
        index = self._index(ids, mode, len(local))
        labels = torch.full_like(ids, -100) if generation else labels_for(ids, self.assist, self.aend, self.audio_pad)
        if not generation:
            assert int((labels[:, 1] >= 0).sum()) == len(codes), 'Target frame supervision changed'
            assert int((labels[:, 0] == self.aend).sum()) == 1, 'Reference end leaked into the loss'
        return {'input_ids': ids, 'labels': labels, 'score_index': index,
                'global_values': glob, 'local_values': local, 'mode': mode}

    def collate(self, examples):
        from pack_moss import collate
        batch = collate(examples, self.text_pad, self.audio_pad)
        B, T = batch['attention_mask'].shape
        S = max(1, max(len(row['local_values']) for row in examples))
        glob = torch.tensor([row['global_values'] for row in examples], dtype=torch.float32)
        local = torch.zeros(B, S, 2 * len(self.schema['local_dimensions']), dtype=torch.float32)
        index = torch.zeros(B, T, dtype=torch.long)
        for i, row in enumerate(examples):
            index[i, :len(row['score_index'])] = row['score_index']
            if row['local_values']:
                local[i, :len(row['local_values'])] = torch.tensor(row['local_values'])
        batch['score_conditioning'] = (glob, local, index)
        batch['modes'] = [row['mode'] for row in examples]
        return batch