app.py

import os, re, time, tempfile, traceback
import gradio as gr
from dotenv import load_dotenv
from openai import OpenAI
from langdetect import detect, DetectorFactory

from srt_utils import (
    parse_srt, blocks_to_srt, split_batches,
    validate_srt_batch, last_end_time_ms
)
from prompts import build_prompt, RTL_LANGS

load_dotenv()
DetectorFactory.seed = 42

DEFAULT_GLOSSARY = """agency - יכולת פעולה עצמאית
attachment - היקשרות
awakening - התעוררות
alaya - אלאיה
ayatana - אייטנה (בסיס החושים)"""

LANG_NAME_TO_CODE = {
    "English": "en",
    "Hebrew": "he",
    "Spanish": "es",
    "French": "fr",
    "German": "de",
    "Arabic": "ar",
    "Auto-detect": "auto",
}

def simple_token_estimate(text: str) -> int:
    lines = []
    for block in parse_srt(text):
        lines.extend(block[2:])  # text-only lines
    only_text = " ".join(lines)
    words = len(re.findall(r"\S+", only_text))
    return int(words * 1.33)

def estimate_cost(total_in_tokens: int,
                  total_out_tokens: int,
                  price_in_per_million: float,
                  price_out_per_million: float) -> float:
    cost_in = (total_in_tokens / 1_000_000.0) * price_in_per_million
    cost_out = (total_out_tokens / 1_000_000.0) * price_out_per_million
    return round(cost_in + cost_out, 4)

def autodetect_source_lang(srt_text: str) -> str:
    texts = []
    for block in parse_srt(srt_text)[:50]:
        texts.extend(block[2:])
    sample = " ".join(texts)[:1000].strip()
    if not sample:
        return "English"
    try:
        code = detect(sample)
    except Exception:
        return "English"
    for name, c in LANG_NAME_TO_CODE.items():
        if c == code:
            return name
    return "English"

def _read_srt_input(file_input):
    """
    Accept bytes (from gr.File with type='binary'), dict payloads, a filepath string,
    or a NamedString-like object. Return decoded UTF-8 text.
    """
    if file_input is None:
        return None
    # Dict payload (some gradio versions)
    if isinstance(file_input, dict):
        data = file_input.get("data")
        name = file_input.get("name")
        if isinstance(data, (bytes, bytearray)):
            try:
                return data.decode("utf-8", errors="replace")
            except Exception:
                return data.decode("latin-1", errors="replace")
        if isinstance(name, str) and os.path.exists(name):
            with open(name, "rb") as f:
                raw = f.read()
            try:
                return raw.decode("utf-8", errors="replace")
            except Exception:
                return raw.decode("latin-1", errors="replace")
    # bytes or bytearray
    if isinstance(file_input, (bytes, bytearray)):
        try:
            return file_input.decode("utf-8", errors="replace")
        except Exception:
            return file_input.decode("latin-1", errors="replace")
    # NamedString with .name -> temp path
    name = getattr(file_input, "name", None)
    if isinstance(name, str) and os.path.exists(name):
        with open(name, "rb") as f:
            raw = f.read()
        try:
            return raw.decode("utf-8", errors="replace")
        except Exception:
            return raw.decode("latin-1", errors="replace")
    # string path
    if isinstance(file_input, str) and os.path.exists(file_input):
        with open(file_input, "rb") as f:
            raw = f.read()
        try:
            return raw.decode("utf-8", errors="replace")
        except Exception:
            return raw.decode("latin-1", errors="replace")
    # Fallback
    return str(file_input)

def call_gpt(client: OpenAI, model: str, prompt: str, request_timeout: int = 60) -> str:
    resp = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": prompt}],
        temperature=0.0,
        top_p=1.0,
        extra_body={"verbosity": "low"},
        timeout=request_timeout
    )
    text = resp.choices[0].message.content
    m = re.search(r'<<<SRT>>>\s*(.*?)\s*<<<END>>>', text, re.DOTALL)
    return (m.group(1).strip() if m else text.strip())

def prepare_download_file(content: str, suffix: str):
    tmp = tempfile.NamedTemporaryFile(delete=False, suffix=suffix)
    with open(tmp.name, "w", encoding="utf-8") as f:
        f.write(content)
    return tmp.name

def compute_estimates(file_bytes, approx_blocks, use_prev_ctx,
                      price_in_per_million, price_out_per_million, debug=False):
    try:
        raw = _read_srt_input(file_bytes)
        if not raw:
            return "Upload an SRT to estimate.", gr.update(visible=False), gr.update(visible=False)
        base_tokens = simple_token_estimate(raw)
        blocks = parse_srt(raw)
        batch_count = max(1, (len(blocks) + approx_blocks - 1) // approx_blocks)
        prefix_tokens_per_batch = 300
        context_overhead = 0
        if use_prev_ctx and batch_count > 1:
            context_overhead = int((base_tokens / batch_count) * 0.5) * (batch_count - 1)
        in_tokens = base_tokens + batch_count * prefix_tokens_per_batch + context_overhead
        out_tokens = base_tokens
        total_cost = estimate_cost(in_tokens, out_tokens, price_in_per_million, price_out_per_million)
        if debug:
            msg = (
                "[DEBUG] base tokens: ~%s, batches: %s\n" % (base_tokens, batch_count)
                +
            f"Estimated tokens — input: ~{in_tokens:,}, output: ~{out_tokens:,}\n"
            f"Estimated total cost: ~${total_cost:.4f} (rates: in ${price_in_per_million}/M, out ${price_out_per_million}/M)\n"
            f"Assumptions: words→tokens≈1.33, per-batch prefix≈{prefix_tokens_per_batch}, "
            f"{'with' if use_prev_ctx else 'no'} previous-batch context."
        )
        # Important: keep download buttons hidden for estimator
        return msg, gr.update(visible=False), gr.update(visible=False)
    except Exception as e:
        return f"[Estimator error] {e}", gr.update(visible=False), gr.update(visible=False)

def pipeline(file_bytes, user_api_key, source_lang, target_lang, glossary, extra, model, approx_blocks, use_prev_ctx, debug=False):
    SAFE_FILE_HIDDEN = gr.update(value=None, visible=False)
    try:
        api_key = (user_api_key or "").strip() or os.getenv("OPENAI_API_KEY", "").strip()
        if not api_key:
            return "", "Please paste your OpenAI API key or configure OPENAI_API_KEY.", SAFE_FILE_HIDDEN, SAFE_FILE_HIDDEN, "ltr"
        client = OpenAI(api_key=api_key, timeout=60)

        raw = _read_srt_input(file_bytes)
        if not raw:
            return "", "Please upload an SRT file.", SAFE_FILE_HIDDEN, SAFE_FILE_HIDDEN, "ltr"
        in_blocks = parse_srt(raw)

        if source_lang == "Auto-detect":
            source_lang = autodetect_source_lang(raw)

        for b in in_blocks:
            if len(b) < 3 or not b[0].strip().isdigit() or "-->" not in b[1]:
                return "", "Input SRT failed basic validation (numbers/timecodes).", SAFE_FILE_HIDDEN, SAFE_FILE_HIDDEN, "ltr"

        out_blocks_all, logs = [], []
        if debug:
            logs.append('[DEBUG] Starting pipeline with %d blocks' % len(in_blocks))
        prev_source, prev_target = None, None

        
        # initial progress ping
        yield "", "Starting translation…", gr.update(value=None, visible=False), gr.update(value=None, visible=False), ("rtl" if target_lang.lower()[:2] in RTL_LANGS else "ltr")

        for i, batch in enumerate(split_batches(in_blocks, approx_blocks), start=1):
            batch_srt_in = blocks_to_srt(batch)
            prompt = build_prompt(
                source_lang=source_lang, target_lang=target_lang,
                batch_srt=batch_srt_in, glossary_text=glossary, extra_instructions=extra,
                prev_source=prev_source if use_prev_ctx else None,
                prev_target=prev_target if use_prev_ctx else None
            )
            if debug:
                logs.append('[DEBUG] Prompt length chars=%d' % len(prompt))
            logs.append('Calling OpenAI…')
            yield blocks_to_srt(out_blocks_all), "\n".join(logs), gr.update(value=None, visible=False), gr.update(value=None, visible=False), ("rtl" if target_lang.lower()[:2] in RTL_LANGS else "ltr")
            try:
                translated = call_gpt(client, model, prompt, request_timeout=60)
            except Exception as e:
                logs.append(f"[ERROR] API call failed in batch {i}: {e}")
                srt_path = prepare_download_file(blocks_to_srt(out_blocks_all), ".srt")
                log_path = prepare_download_file("\n".join(logs), ".log.txt")
                return blocks_to_srt(out_blocks_all), "\n".join(logs), srt_path, log_path, ("rtl" if target_lang.lower()[:2] in RTL_LANGS else "ltr")

            out_batch = parse_srt(translated)
            prev_end = last_end_time_ms(out_blocks_all)
            ok, rep = validate_srt_batch(batch, out_batch, prev_last_end=prev_end)
            logs.append(f"Batch {i}: {'OK' if ok else 'ISSUES'}")
            logs += rep

            if not ok:
                prompt_strict = prompt + "\n\n(HARD MODE) Repeat EXACT numbers/timecodes/line counts. Output SRT only."
                try:
                    logs.append('Retrying with strict constraints…')
                    yield blocks_to_srt(out_blocks_all), "\n".join(logs), gr.update(value=None, visible=False), gr.update(value=None, visible=False), ("rtl" if target_lang.lower()[:2] in RTL_LANGS else "ltr")
                    translated2 = call_gpt(client, model, prompt_strict, request_timeout=60)
                    out_batch2 = parse_srt(translated2)
                    ok2, rep2 = validate_srt_batch(batch, out_batch2, prev_last_end=prev_end)
                    logs.append(f"Batch {i} (retry): {'OK' if ok2 else 'ISSUES'}")
                    logs += rep2
                    if ok2:
                        out_batch = out_batch2
                        ok = True
                except Exception as e:
                    logs.append(f"[ERROR] Retry failed in batch {i}: {e}")

            out_blocks_all.extend(out_batch)
            prev_source, prev_target = batch_srt_in, blocks_to_srt(out_batch)

            yield blocks_to_srt(out_blocks_all), "\n".join(logs), SAFE_FILE_HIDDEN, SAFE_FILE_HIDDEN, ("rtl" if target_lang.lower()[:2] in RTL_LANGS else "ltr")
            time.sleep(0.05)

        final_srt = blocks_to_srt(out_blocks_all)
        direction = "rtl" if target_lang.lower()[:2] in RTL_LANGS else "ltr"
        srt_path = prepare_download_file(final_srt, ".srt")
        log_path = prepare_download_file("\n".join(logs) if logs else "Done.", ".log.txt")
        return final_srt, "\n".join(logs) if logs else "Done.", srt_path, log_path, direction

    except Exception as e:
        tb = traceback.format_exc()
        return "", f"[FATAL] {e}\n\n{tb}", SAFE_FILE_HIDDEN, SAFE_FILE_HIDDEN, "ltr"

with gr.Blocks(title="Open Subtitle Translator (GPT-5)") as demo:
    gr.Markdown("## Open Subtitle Translator — GPT-5\nPaste your API key, upload an SRT, pick languages, and translate with strict SRT validation.")

    with gr.Row():
        key = gr.Textbox(label="OpenAI API key", type="password", placeholder="sk-...", info="Used only for this session; not stored.")
        model = gr.Dropdown(choices=["gpt-5", "gpt-5-mini"], value="gpt-5", label="Model")
        approx_blocks = gr.Slider(5, 20, value=10, step=1, label="Approx. SRT blocks per batch")
        use_prev = gr.Checkbox(value=True, label="Use previous-batch target as context")

    with gr.Row():
        src = gr.Dropdown(choices=["Auto-detect", "English", "Hebrew", "Spanish", "French", "German", "Arabic"], value="English", label="Source language")
        tgt = gr.Dropdown(choices=["Hebrew", "English", "Spanish", "French", "German", "Arabic"], value="Hebrew", label="Target language")

    with gr.Row():
        price_in = gr.Number(value=1.25, precision=2, label="Price — input $/M tokens (configurable)")
        price_out = gr.Number(value=10.0, precision=2, label="Price — output $/M tokens (configurable)")

    glossary = gr.Textbox(label="Glossary / Policy", value=DEFAULT_GLOSSARY, lines=6)
    extra = gr.Textbox(label="Extra instructions (optional)", lines=4, placeholder="Tone, domain hints, speaker info…")

    srt_in = gr.File(label="Upload SRT", file_types=[".srt"], type="binary")

    with gr.Row():
        estimate_btn = gr.Button("Estimate Cost")
        run_btn = gr.Button("Translate")
        debug = gr.Checkbox(value=False, label="Debug mode")

    srt_preview = gr.Textbox(label="Translated SRT (preview)", lines=18)
    log = gr.Textbox(label="Validation / Log", lines=18)

    with gr.Row():
        dl_srt = gr.File(label="Download Translated SRT", visible=False)
        dl_log = gr.File(label="Download Log", visible=False)

    dir_state = gr.State("ltr")

    estimate_btn.click(
        fn=compute_estimates,
        inputs=[srt_in, approx_blocks, use_prev, price_in, price_out, debug],
        outputs=[log, dl_srt, dl_log],
        api_name="estimate"
    )

    run_btn.click(
        fn=pipeline,
        inputs=[srt_in, key, src, tgt, glossary, extra, model, approx_blocks, use_prev, debug],
        outputs=[srt_preview, log, dl_srt, dl_log, dir_state],
        api_name="translate",
        queue=True
    )

if __name__ == "__main__":
    demo.queue().launch()