"""Batch audio generation from a manifest file.

Processes assets in order: Stable Audio generation (`method: sao`) or harmonic
synthesis (`method: synth`), each followed by post-processing to OGG.

Formerly tooling/db/audio_batch.py behind the audio-batch wrapper (T-1290). It
used to re-launch audio_connector.py and audio_post.py as subprocesses and
parse their stdout; it now calls them. The synthesis itself is unchanged —
same parameters give byte-identical WAVs. One behaviour change: a batch with
failures used to print `"ok": false` and exit 0; the router now fails it.

Manifest schema (docs/assets/audio/, see the audio-gen skill):
    {"output_dir": ..., "gen_dir": ..., "defaults": {steps, cfg, timeout, lufs, quality},
     "assets": [{"id", "filename", "method": "sao"|"synth", "prompt"?, "duration"?,
                 "synth"?: {"type": "harmonic", "duration", "fundamental",
                            "harmonics": [{"freq", "db"}], "attack_ms",
                            "sustain_ratio", "decay": "exponential"|"linear"}}]}
"""

from __future__ import annotations

import json
import os
import wave

import numpy as np

from tooling.core import config, console
from tooling.core.errors import ReachError
from tooling.domains.assets import audio, audio_post

SAMPLE_RATE = 44100


def load_manifest(path: str) -> dict:
    try:
        with open(path) as f:
            return json.load(f)
    except FileNotFoundError as exc:
        raise ReachError(f"manifest not found: {path}", fix="pass a manifest .json path") from exc
    except json.JSONDecodeError as exc:
        raise ReachError(f"manifest is not valid JSON: {path}: {exc}", fix="fix the JSON, then re-run") from exc


def resolve_paths(manifest: dict) -> tuple[str, str]:
    """output_dir and gen_dir, relative to the repo root (created if missing).

    The old script found the root by walking up from the manifest looking for
    .git; config.repo_root() asks git, which gives the same answer in a
    worktree and does not silently fall back to the manifest's own directory.
    """
    root = str(config.repo_root())
    output_dir = os.path.join(root, manifest.get("output_dir", "client/assets/audio"))
    gen_dir = os.path.join(root, manifest.get("gen_dir", "client/assets/audio/gen"))
    os.makedirs(output_dir, exist_ok=True)
    os.makedirs(gen_dir, exist_ok=True)
    return output_dir, gen_dir


def get_default(manifest: dict, asset: dict, key: str):
    """An asset value, falling back to the manifest's defaults."""
    return asset.get(key, manifest.get("defaults", {}).get(key))


def run_sao_generate(asset: dict, manifest: dict, gen_dir: str, output_dir: str) -> dict:
    """Generate via Stable Audio, post-processing straight to the final OGG."""
    filename = asset["filename"]
    base_name = os.path.splitext(filename)[0]
    return audio.generate(
        asset["prompt"],
        duration=asset.get("duration", 10),
        steps=get_default(manifest, asset, "steps") or 100,
        cfg=get_default(manifest, asset, "cfg") or 7,
        output=os.path.join(gen_dir, base_name + ".wav"),
        timeout=get_default(manifest, asset, "timeout") or 600,
        output_ogg=os.path.join(output_dir, filename),
    )


def synthesize_harmonic(params: dict, wav_path: str) -> str:
    """Synthesize a tone from harmonic parameters and write a 16-bit mono WAV."""
    sr = SAMPLE_RATE
    duration = params["duration"]
    fundamental = params["fundamental"]
    harmonics = params.get("harmonics", [])
    attack_ms = params.get("attack_ms", 10)
    sustain_ratio = params.get("sustain_ratio", 0.2)
    decay = params.get("decay", "exponential")

    n = int(sr * duration)
    t = np.linspace(0, duration, n, endpoint=False)

    signal = np.sin(2 * np.pi * fundamental * t)
    for h in harmonics:
        amplitude = 10 ** (h["db"] / 20)
        signal = signal + amplitude * np.sin(2 * np.pi * h["freq"] * t)

    # Envelope: attack + sustain + decay.
    attack_s = attack_ms / 1000
    attack_env = np.minimum(t / attack_s, 1.0) if attack_s > 0 else np.ones(n)

    sustain_end = duration * sustain_ratio
    if decay == "exponential":
        # Reach -60 dB by the end of the duration.
        decay_rate = 6.9 / (duration - sustain_end) if duration > sustain_end else 10
        decay_env = np.where(t < sustain_end, 1.0, np.exp(-decay_rate * (t - sustain_end)))
    else:
        decay_env = np.where(t < sustain_end, 1.0, 1.0 - (t - sustain_end) / (duration - sustain_end))

    signal = signal * attack_env * decay_env

    peak = np.max(np.abs(signal))
    if peak > 0:
        signal = signal / peak * 0.9

    int_samples = np.clip(signal * 32767, -32767, 32767).astype(np.int16)
    with wave.open(wav_path, "w") as f:
        f.setnchannels(1)
        f.setsampwidth(2)
        f.setframerate(sr)
        f.writeframes(int_samples.tobytes())
    return wav_path


def run_synth(asset: dict, manifest: dict, gen_dir: str, output_dir: str) -> dict:
    """Synthesize, then normalize + convert (no trim: synth has no silence to trim)."""
    filename = asset["filename"]
    base_name = os.path.splitext(filename)[0]
    wav_path = os.path.join(gen_dir, base_name + "_synth.wav")
    norm_path = os.path.join(gen_dir, base_name + "_norm.wav")
    ogg_path = os.path.join(output_dir, filename)

    synth_params = asset.get("synth")
    if not synth_params:
        return {"ok": False, "error": "No synth parameters provided"}
    if synth_params.get("type", "harmonic") != "harmonic":
        return {"ok": False, "error": f"Unknown synth type: {synth_params.get('type')}"}

    try:
        synthesize_harmonic(synth_params, wav_path)
        audio_post.normalize(wav_path, norm_path, lufs=get_default(manifest, asset, "lufs") or -16)
        audio_post.convert(norm_path, ogg_path, quality=get_default(manifest, asset, "quality") or 6)
    except ReachError as exc:
        return {"ok": False, "error": exc.message}
    finally:
        if os.path.exists(norm_path):
            os.remove(norm_path)

    return {
        "ok": True,
        "file": wav_path,
        "ogg_file": ogg_path,
        "ogg_size_bytes": os.path.getsize(ogg_path),
        "synth_params": synth_params,
        "post_processed": True,
    }


def run(
    manifest_path: str,
    *,
    dry_run: bool = False,
    only: set[str] | None = None,
    skip_existing: bool = False,
) -> dict:
    """Process a manifest; returns the summary. The router fails it on any failure."""
    manifest = load_manifest(manifest_path)
    output_dir, gen_dir = resolve_paths(manifest)

    assets = manifest.get("assets", [])
    if only:
        assets = [a for a in assets if a["id"] in only]

    # One health check up front if anything needs Stable Audio — so an OFF
    # service fails once, with the right remedy, not once per asset.
    if not dry_run and any(a.get("method") == "sao" for a in assets):
        console.event("Checking Stable Audio health...")
        audio.health()

    total = len(assets)
    results = []
    counts = {"success": 0, "failed": 0, "skipped": 0}
    console.event(
        f"Processing {total} assets from {os.path.basename(manifest_path)}"
        + (" — dry run, nothing generated" if dry_run else "")
    )

    for i, asset in enumerate(assets, 1):
        asset_id, filename = asset["id"], asset["filename"]
        method = asset.get("method", "sao")
        phase = f"{i}/{total}"
        console.event(f"{asset_id}: {filename} ({method})", phase=phase, progress=i / total if total else None)

        if skip_existing and os.path.exists(os.path.join(output_dir, filename)):
            console.event("skipping — already exists", phase=phase)
            results.append({"id": asset_id, "status": "skipped", "reason": "exists"})
            counts["skipped"] += 1
            continue

        if dry_run:
            if method == "sao":
                console.event(f"would generate — prompt: {asset.get('prompt', '(none)')[:80]}...", phase=phase)
            elif method == "synth":
                synth = asset.get("synth", {})
                console.event(
                    f"would synthesize — {synth.get('fundamental')}Hz, {synth.get('duration')}s", phase=phase
                )
            results.append({"id": asset_id, "status": "dry_run"})
            continue

        if method == "sao":
            try:
                result = run_sao_generate(asset, manifest, gen_dir, output_dir)
            except ReachError as exc:
                result = {"ok": False, "error": exc.message}
        elif method == "synth":
            result = run_synth(asset, manifest, gen_dir, output_dir)
        else:
            result = {"ok": False, "error": f"Unknown method: {method}"}

        result["id"] = asset_id
        if result.get("ok"):
            counts["success"] += 1
            result["status"] = "success"
            console.event(f"OK → {result.get('ogg_file', filename)}", phase=phase)
        else:
            counts["failed"] += 1
            result["status"] = "failed"
            console.event(f"FAILED: {result.get('error', 'unknown')}", phase=phase, level="warn")
        results.append(result)

    return {"ok": counts["failed"] == 0, "total": total, **counts, "results": results}