###############################################################################
#  app.py  –  EAL Emergent-Discourse Analyzer  (Gemma 1 / 2 / 3 compliant)
###############################################################################
import gc, io, json, re, time, base64
import torch, numpy as np, matplotlib, matplotlib.pyplot as plt, seaborn as sns
import gradio as gr
from transformers import AutoTokenizer, AutoModelForCausalLM
from sklearn.metrics.pairwise import cosine_similarity
from sklearn.cluster import KMeans

matplotlib.use("Agg")  # headless

# ──────────────────────────────────────────────────────────────────────────────
# 1 · Registry of models
# ──────────────────────────────────────────────────────────────────────────────
AVAILABLE_MODELS = {
    "GPT-Neox-1.3B"      : "EleutherAI/gpt-neo-1.3B",
    "GPT-2"              : "gpt2",
    "Gemma 1.1 2B-IT"    : "google/gemma-1.1-2b-it",
    "Gemma 2 2B-IT"      : "google/gemma-2-2b-it",
    "Gemma 3 1B-IT"      : "google/gemma-3-1b-it",
}

_loaded, _current = {}, None
dbg_log: list[str] = []

def dbg(msg: str) -> None:
    ts = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime())
    line = f"[{ts}] {msg}"
    dbg_log.append(line)
    print(line)

# ──────────────────────────────────────────────────────────────────────────────
# 2 · Loader helpers  (BF16-aware & VRAM-safe)
# ──────────────────────────────────────────────────────────────────────────────
def _gpu_supports_bf16() -> bool:
    if not torch.cuda.is_available(): return False
    major, _ = torch.cuda.get_device_capability()
    return major >= 8   # Ampere (8.0) or newer

def _unload_current():
    global _current
    if _current and _current in _loaded:
        _loaded[_current]["model"].to("cpu")
    torch.cuda.empty_cache(); gc.collect()
    _current = None

def _load(name: str):
    """Lazy load or swap in the requested model."""
    global tokenizer, model, MODEL_CTX, device, _current
    if name == _current: return
    dbg(f"[boot] switching → {name}")
    _unload_current()

    if name in _loaded:                        # cached
        obj = _loaded[name]
        tokenizer, model, MODEL_CTX, device = obj["tok"], obj["model"], obj["ctx"], obj["dev"]
        _current = name; return

    repo = AVAILABLE_MODELS[name]
    torch_dtype = torch.bfloat16 if _gpu_supports_bf16() else torch.float16
    tok = AutoTokenizer.from_pretrained(repo, use_fast=True)
    mdl = AutoModelForCausalLM.from_pretrained(repo, torch_dtype=torch_dtype)
    dev = torch.device("cuda" if torch.cuda.is_available() else "cpu")
    mdl.to(dev).eval()

    ctx_raw = getattr(mdl.config, "max_position_embeddings", 2048)
    ctx = int(min(ctx_raw, 8192))              # Gemma-3 reports 1e15 – clamp
    if tok.pad_token is None:
        tok.pad_token = tok.eos_token
        mdl.config.pad_token_id = mdl.config.eos_token_id

    _loaded[name] = {"tok": tok, "model": mdl, "ctx": ctx, "dev": dev}
    tokenizer, model, MODEL_CTX, device, _current = tok, mdl, ctx, dev, name
    dbg(f"[boot] {name} ready (ctx={ctx}, dev={dev}, dtype={torch_dtype})")

# prime default
_load("GPT-Neox-1.3B")

# ──────────────────────────────────────────────────────────────────────────────
# 3 · Utility fns  (unchanged)
# ──────────────────────────────────────────────────────────────────────────────
PROMPT_HEADROOM, MAX_GEN = 300, 100
_q = re.compile(r'"')
def esc(t): return _q.sub('\\"', t)

def trim(t, rv=80):
    toks = tokenizer.encode(t, add_special_tokens=False)
    keep = MODEL_CTX - PROMPT_HEADROOM - rv
    return tokenizer.decode(toks[-keep:], skip_special_tokens=True) if len(toks) > keep else t

def cosine(a, b):
    noisy = ("[Generation Error", "[Context window full]", "[Model not")
    if any(m in a for m in noisy) or any(m in b for m in noisy): return 0.0
    with torch.inference_mode():
        emb = model.get_input_embeddings()
        ta = emb(tokenizer(a, return_tensors="pt").to(device).input_ids).mean(1)
        tb = emb(tokenizer(b, return_tensors="pt").to(device).input_ids).mean(1)
    return max(min(float(cosine_similarity(ta.cpu(), tb.cpu())[0,0]),1),-1)

def generate(prompt, temp):
    dbg(f"PROMPT >>> {prompt}")
    with torch.inference_mode():
        inp = tokenizer(prompt, return_tensors="pt").to(device)
        out = model.generate(
            **inp,
            max_length=min(inp.input_ids.size(1)+MAX_GEN, MODEL_CTX),
            temperature=temp, top_p=0.9,
            repetition_penalty=1.2, no_repeat_ngram_size=3,
            pad_token_id=tokenizer.pad_token_id,
        )
    ans = tokenizer.decode(out[0][inp.input_ids.size(1):], skip_special_tokens=True).strip()
    dbg(f"OUTPUT <<< {ans}")
    return ans or "[Empty]"

def heat(mat, labels, title):
    mask=np.isnan(mat)
    fig, ax=plt.subplots(figsize=(max(8,len(labels)), max(7,len(labels)*0.9)))
    sns.heatmap(mat,mask=mask,annot=True,cmap="plasma",fmt=".2f",
                vmin=np.nanmin(mat)*0.97,vmax=1,annot_kws={"size":7},
                xticklabels=labels, yticklabels=labels, ax=ax)
    plt.xticks(rotation=45,ha="right"); plt.yticks(rotation=0)
    ax.set_title(title,pad=18); plt.tight_layout(pad=2.3)
    buf=io.BytesIO(); plt.savefig(buf,format="png"); plt.close(fig); buf.seek(0)
    return f"<img src='data:image/png;base64,{base64.b64encode(buf.read()).decode()}' style='max-width:95%;height:auto;'/>"

# ──────────────────────────────────────────────────────────────────────────────
# 4 · Main EAL routine  (unchanged logic)
# ──────────────────────────────────────────────────────────────────────────────
def run_eal(iters:int, mdl:str, prog=gr.Progress()):
    dbg_log.clear(); _load(mdl)
    I,nI,dI,dnI,dx=[None]*iters,[None]*iters,[None]*iters,[None]*iters,[None]*iters
    seed="A thinking process begins. The first thought is:"
    for k in range(iters):
        prm = seed if not k else (
            f'The thought process previously generated: "{esc(trim(I[k-1],60))}"\n\n'
            "Task: Continue this line of thought. What logically follows or develops?"
        )
        I[k]=generate(prm,0.7)
        prm_n=(f'Consider the statement: "{esc(trim(I[k],80))}"\n\n'
               "Task: Explore alternative perspectives or potential issues. "
               "What might be a contrasting viewpoint or an overlooked aspect?")
        nI[k]=generate(prm_n,0.9)
        if k: dI[k]=cosine(I[k-1],I[k]); dnI[k]=cosine(nI[k-1],nI[k])
        dx[k]=cosine(I[k],nI[k]); prog((k+1)/iters)

    # clusters
    labels=[f"I{k}" for k in range(iters)]+[f"¬I{k}" for k in range(iters)]
    vecs,lab=[],[]
    with torch.inference_mode():
        emb=model.get_input_embeddings()
        for t,l in zip(I+nI,labels):
            if t.startswith("["):continue
            vecs.append(emb(tokenizer(t,return_tensors="pt").to(device).input_ids).mean(1).cpu().numpy().squeeze()); lab.append(l)
    clus={l:"N/A" for l in labels}
    if len(vecs)>=2: clus.update({l:f"C{c}" for l,c in zip(lab,KMeans(2,random_state=0,n_init=10).fit(np.vstack(vecs)).labels_)})

    def block(seq,tag): return "\n\n---\n\n".join(f"**{tag}{i} [{clus.get(f'{tag}{i}','N/A')}]**:\n{t}" for i,t in enumerate(seq))
    tbl=["|Iter|ΔS(I)|ΔS(¬I)|ΔS(I,¬I)|","|:--:|:---:|:----:|:------:|"]
    tbl+=[f"|{i}|{('N/A' if dI[i] is None else f'{dI[i]:.4f}')}|"
          f"{('N/A' if dnI[i] is None else f'{dnI[i]:.4f}')}|"
          f"{('N/A' if dx[i]  is None else f'{dx[i]:.4f}')}|" for i in range(iters)]

    n=len(labels); mat=np.full((n,n),np.nan)
    for a in range(n):
        for b in range(a,n):
            sim=1 if a==b else cosine((I+nI)[a],(I+nI)[b])
            mat[a,b]=mat[b,a]=sim

    return block(I,"I"),block(nI,"¬I"),"\n".join(tbl),"\n".join(dbg_log),heat(mat,labels,f"Similarity Matrix ({iters} iters • {mdl})")

# ──────────────────────────────────────────────────────────────────────────────
# 5 · Gradio UI
# ──────────────────────────────────────────────────────────────────────────────
with gr.Blocks(theme=gr.themes.Soft(primary_hue="teal")) as demo:
    gr.Markdown("## EAL · Emergent-Discourse Analyzer  (Gemma 1 / 2 / 3 ready)")
    mdl_dd=gr.Dropdown(list(AVAILABLE_MODELS.keys()),value="GPT-Neox-1.3B",label="Model")
    iters=gr.Slider(1,7,3,1,label="Iterations")
    run=gr.Button("Run 🚀",variant="primary")
    with gr.Tabs():
        with gr.Tab("Traces"):
            outI,outnI=gr.Markdown(),gr.Markdown()
        with gr.Tab("ΔS + Heatmap"):
            outTbl,outHm=gr.Markdown(),gr.HTML()
        with gr.Tab("Debug (full prompts & answers)"):
            outDbg=gr.Textbox(lines=26,interactive=False,show_copy_button=True)
    run.click(run_eal,[iters,mdl_dd],[outI,outnI,outTbl,outDbg,outHm])

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