"""Khung chat của Co4E và việc đếm token — R08-T09.

Khác chat của Cowork ở một điểm: ở đây câu người dùng gõ có thể mang chỉ thị
chọn agent (``_extract_agent_directive``), và mỗi lượt được định tuyến riêng
theo cấu hình routing của Co4E.
"""
from __future__ import annotations

import re
from typing import Dict, List
from PySide6.QtCore import QSize, Qt
from PySide6.QtWidgets import QSplitter, QWidget
from ...core import co4e, skills as skills_mod
from ...core.co4e_builtins import BUILTIN_AGENTS
from ...core.worker import AgentWorker
from ...i18n import tr
from ...ui.chat_view import ChatView
from ...ui.icons import icon
from ...presentation.co4e.co4e_chat_view import ChatPanel


class Co4EChatMixin:
    def _build_chat(self) -> QWidget:
        """Widget construction lives in ``ChatPanel`` (presentation/co4e/
        co4e_chat_view.py); this method just wires the panel's public
        attributes to the handler methods that know about ``self``
        (``_toggle_messages``, ``_chat_send``) and keeps the state that is
        NOT part of the panel's own construction (``_flow_logs`` — per-flow
        ChatView dict, ``_co4e_routed_provider`` — routing override, and
        ``_vsplit_sizes``/``_msgs_collapsed`` — used by ``_toggle_messages``
        below to restore/collapse the splitter) — the panel itself stays
        ignorant of ``Co4ETab``.
        """
        panel = ChatPanel(self.ctx)
        self._chat_widget = panel
        self.msgs_icon = panel.msgs_icon
        self.msgs_title = panel.msgs_title
        self.chat_toggle_btn = panel.chat_toggle_btn
        self.chat_toggle_btn.clicked.connect(self._toggle_messages)
        self._mhdr = panel.header
        self.chat_stack = panel.chat_stack
        self._flow_logs: Dict[str, ChatView] = {}
        self.chat_input_row = panel.chat_input_row
        self._usage_total_lbl = panel.usage_total_lbl
        self.chat_input = panel.chat_input
        self.chat_input.submit.connect(self._chat_send)
        self.chat_send_btn = panel.chat_send_btn
        self.chat_send_btn.clicked.connect(self._chat_send)
        self.co4e_routing_toggle = panel.co4e_routing_toggle
        self._co4e_routed_provider = None   # routing provider override for the next turn
        self._vsplit_sizes = [540, 220]         # sizes to restore when expanded
        self._msgs_collapsed = True
        return panel
    def _toggle_messages(self) -> None:
        """Show/hide the WHOLE chat box (message list + composer) below the
        header. Collapsing hands the freed height to the canvas.

        A QSplitter's ``setMaximumHeight`` on one side does NOT automatically
        redistribute the freed space to the other side — it just shrinks the
        splitter's own total height, leaving the canvas frozen at its old size
        and blank space below it. So this explicitly calls ``setSizes`` on both
        the collapse AND the expand path, computed from the splitter's CURRENT
        total (not a hardcoded guess) — that total stays constant; only how
        it's split between canvas/chat changes."""
        self._msgs_collapsed = not self._msgs_collapsed
        collapsed_h = self._mhdr.sizeHint().height() + 6
        if self._msgs_collapsed:
            if hasattr(self, "_vsplit"):
                self._vsplit_sizes = self._vsplit.sizes()   # remember to restore
            self.chat_stack.hide()
            self.chat_input_row.hide()
            self._chat_widget.setMaximumHeight(collapsed_h)
            self.chat_toggle_btn.setIcon(icon("chevron-up"))     # collapsed → click to expand
            self.chat_toggle_btn.setToolTip(tr("co4e.tt_expand_msgs"))
            if hasattr(self, "_vsplit"):
                total = sum(self._vsplit.sizes()) or (self._vsplit_sizes and sum(self._vsplit_sizes)) or 760
                self._vsplit.setSizes([max(0, total - collapsed_h), collapsed_h])
        else:
            self._chat_widget.setMaximumHeight(16777215)
            self.chat_stack.show()
            self.chat_input_row.show()
            self.chat_toggle_btn.setIcon(icon("chevron-down"))   # expanded → click to collapse
            self.chat_toggle_btn.setToolTip(tr("co4e.tt_collapse_msgs"))
            if getattr(self, "_vsplit_sizes", None) and hasattr(self, "_vsplit"):
                self._vsplit.setSizes(self._vsplit_sizes)
        return
    def _ensure_flow_log(self, wf_id: str) -> ChatView:
        """The ChatView for a flow, created + added to the stack on first use so
        each flow tab keeps a SEPARATE conversation."""
        log = self._flow_logs.get(wf_id)
        if log is None:
            log = ChatView()
            log._co4e_plan_bubble = None       # per-flow 'current plan' bubble
            self._flow_logs[wf_id] = log
            self.chat_stack.addWidget(log)
        return log
    def _active_log(self) -> ChatView:
        wf = getattr(self, "_wf", None)
        return self._ensure_flow_log(wf.id if wf is not None else "__none__")
    @property
    def chat_log(self) -> ChatView:
        """The conversation of the CURRENTLY-shown flow (all append/stream calls
        go here). Assignment is not supported — logs are per-flow now."""
        return self._active_log()
    @property
    def _plan_bubble(self):
        return getattr(self._active_log(), "_co4e_plan_bubble", None)
    @_plan_bubble.setter
    def _plan_bubble(self, value) -> None:
        self._active_log()._co4e_plan_bubble = value
    def _chat_send(self) -> None:
        text = self.chat_input.text().strip()
        if not text or self._chat_worker is not None:
            return
        self.chat_input.clear()
        self._append_chat("user", text)
        skill_prefix, request, info = skills_mod.parse_skill_command(text)
        if info is not None:
            self._append_chat("system", info)
            return
        system_parts = []
        if skill_prefix:
            system_parts.append(skill_prefix)
        agent_name, request = self._extract_agent_directive(request)
        model = ""
        if agent_name:
            persona = self._resolve_agent(agent_name)
            if persona is None:
                self._append_chat("system", tr("co4e.agent_not_found", name=agent_name))
                return
            system_parts.append(persona[0])
            model = persona[1]
        # Auto Model Routing — only when the user hasn't pinned an agent's own
        # model (an explicit pin wins). May switch provider+model for this turn.
        if not model:
            model = self._apply_co4e_routing(request)
        self._run_chat_turn(system_parts, request, model)
    def _apply_co4e_routing(self, request: str) -> str:
        """Route this Co4E turn to the best-fit model. Returns the model id to
        use ('' → provider default) and sets ``self._co4e_routed_provider`` when
        a cross-provider switch is chosen.

        R03-T05: the Off/Auto/Manual/Fallback rules are no longer re-implemented
        here — they come from the shared ``RoutingApplicationService``, so Co4E,
        the Cowork chat and AI-Edit can never drift apart again. This method only
        adapts between Co4E's state and the service's DTOs. Never raises — falls
        back to the default model on any error.
        """
        self._co4e_routed_provider = None
        try:
            from ...application.model_routing import (
                RoutingRequest,
                build_routing_application_service,
            )
            from ...ui.routing_toggle import confirm_switch

            cur_provider = self.ctx.config.active_provider
            cur_model = self.ctx.config.provider_conf(cur_provider).get("model", "")
            outcome = build_routing_application_service(self.ctx).resolve(
                RoutingRequest(
                    surface="co4e",
                    prompt=request,
                    current_provider=cur_provider,
                    current_model=cur_model,
                ),
                confirm=lambda decision, timeout: confirm_switch(self, decision, timeout),
            )
            if not outcome.switched:
                return ""   # '' keeps the provider's configured default model
            # Remembered so the worker's build_provider_for() can follow a
            # cross-provider switch, not just a model change.
            self._co4e_routed_provider = outcome.provider
            self._append_chat("system", tr(
                "routing.switched_notice",
                model=outcome.model, task=outcome.task_type,
                gain=f"{outcome.score_gain:.2f}"))
            return outcome.model
        except Exception:  # noqa: BLE001 — routing must never block a Co4E turn
            self._co4e_routed_provider = None
            return ""
    def _extract_agent_directive(self, text: str):
        m = re.search(r"(?<!\S)/agent:([\w\-.]+)", text)
        if not m:
            return "", text
        name = m.group(1)
        rest = (text[:m.start()] + " " + text[m.end():]).strip()
        return name, rest
    def _resolve_agent(self, name: str):
        low = name.lower()
        for a in BUILTIN_AGENTS:
            if a.slug == low or a.name.lower() == low:
                return (f"You are the {a.role} agent — {a.name}.\n{a.instructions}", "")
        for ca in co4e.list_custom_agents():
            if co4e.slugify(ca.name) == low or ca.name.lower() == low:
                return (f"You are the {ca.role} agent — {ca.name}.\n{ca.instructions}", ca.model)
        return None
    def _run_chat_turn(self, system_parts: List[str], request: str, model: str) -> None:
        self.chat_send_btn.setEnabled(False)
        log = self.chat_log                 # THIS flow's conversation (captured)
        log._co4e_plan_bubble = None        # a fresh plan for this turn
        ctx = self.ctx
        out_dir = self._out_dir()
        sys_text = "\n\n".join(p for p in system_parts if p)
        prompt = f"{sys_text}\n\n{request}" if sys_text else request
        assistant = log.add_assistant()      # stream into this live bubble
        state = {"text": ""}
        wf = getattr(self, "_wf", None)
        wf_id = wf.id if wf is not None else None
        flow_label = wf.name if wf is not None else "flow"

        def job(worker: AgentWorker):
            from ...core import agent_roles, usage_tracker as ut
            from ...core.chat_agent import run_cowork
            from ...core.co4e_runner import _usage_delta
            # An Auto/Manual routing switch may target a different provider.
            provider = ctx.build_provider_for(getattr(self, "_co4e_routed_provider", None), model or None)
            messages = [{"role": "user", "content": prompt}]
            ut.set_context("co4e", flow_label)   # attribute + measure this turn's usage
            ut.begin_accumulation()
            base = ut.accumulated()

            def _emit(ev):
                if not isinstance(ev, dict):
                    return
                t = ev.get("type")
                if t == "text":
                    worker.emit_event({"type": "text", "delta": ev.get("delta", "")})
                elif t == "plan_set":
                    worker.emit_event({"type": "plan_set", "steps": ev.get("steps") or []})
            try:
                run_cowork(provider, messages, out_dir, _emit, worker.is_cancelled,
                           security_config=ctx.config, agent_role=agent_roles.COWORK,
                           run_to_completion=True, enforce_rules=False)
                usage = _usage_delta(base, ctx.config)
            finally:
                ut.end_accumulation()
            for m in reversed(messages):
                if m.get("role") == "assistant" and m.get("content"):
                    return {"text": str(m["content"]), "usage": usage}
            return {"text": "", "usage": usage}

        def on_event(ev):
            if ev.get("type") == "text":
                state["text"] += ev.get("delta", "")
                assistant.set_markdown(state["text"])
                log.scroll_to_bottom()
            elif ev.get("type") == "plan_set":
                self._append_plan(ev.get("steps") or [], log=log)

        def done(result: dict):
            self._chat_worker = None
            self.chat_send_btn.setEnabled(True)
            final = result.get("text") or state["text"]
            assistant.set_markdown(final or "(no output)")
            self._apply_usage(assistant, wf_id, result.get("usage"))
            log.scroll_to_bottom()

        def failed(err: str):
            self._chat_worker = None
            self.chat_send_btn.setEnabled(True)
            self._append_chat("error", f"[error: {err}]", log=log)

        w = AgentWorker(job)
        w.event.connect(on_event)
        w.finished_ok.connect(done)
        w.failed.connect(failed)
        self._chat_worker = w
        w.start()
    def _append_chat(self, role: str, text: str, log: "ChatView" = None) -> None:
        """Add one message bubble to a flow's conversation. ``log`` defaults to the
        active flow's log; a run/stream passes its OWN captured log so events land
        in the right flow even if the user switches tabs mid-run."""
        log = log or self.chat_log
        if role == "user":
            bub = log.add_user(text)
        elif role == "assistant":
            bub = log.add_assistant()
            bub.set_markdown(text)
        elif role == "error":
            bub = log.add_error(text)
        else:                       # system status marker
            bub = log.add_status(text)
        log.scroll_to_bottom()
        return bub
    def _fmt_usage(self, d_in: int, d_out: int, d_cache: int, cost_usd: float) -> str:
        """The Cowork-style footer string: ↓in ↑out ▤(in+out+cache) $cost, priced
        with the Monitoring model-price table in the app's display currency."""
        from ...core import model_pricing as mp, usage_tracker as ut
        pricing = {**ut.DEFAULT_PRICING, **(self.ctx.config.data.get("usage") or {})}
        return (f"↓{mp.format_tokens(d_in)} ↑{mp.format_tokens(d_out)} "
                f"▤{mp.format_tokens(d_in + d_out + d_cache)} "
                f"{ut.format_cost(cost_usd, pricing)}")
    def _apply_usage(self, bub, wf_id, usage) -> None:
        """Attach a token/cost footer to a step's bubble and add it to the flow's
        running total (mirrors Cowork's per-message + conversation-total display)."""
        if not isinstance(usage, dict):
            return
        d_in = int(usage.get("in", 0) or 0)
        d_out = int(usage.get("out", 0) or 0)
        d_cache = int(usage.get("cache", 0) or 0)
        cost = float(usage.get("cost_usd", 0.0) or 0.0)
        if bub is not None and (d_in or d_out):
            try:
                bub.add_usage(self._fmt_usage(d_in, d_out, d_cache, cost))
            except Exception:  # noqa: BLE001 - a usage footer must never break the run
                pass
        if wf_id is not None:
            tot = self._flow_usage.setdefault(wf_id, {"in": 0, "out": 0, "cache": 0, "cost": 0.0})
            tot["in"] += d_in; tot["out"] += d_out; tot["cache"] += d_cache; tot["cost"] += cost
            self._refresh_usage_total(wf_id)
    def _refresh_usage_total(self, only_wf: str = None) -> None:
        """Update the bottom conversation total to the CURRENT flow's running
        usage (skip if the event is for a different, background flow)."""
        lbl = getattr(self, "_usage_total_lbl", None)
        if lbl is None:
            return
        wf = getattr(self, "_wf", None)
        wf_id = wf.id if wf is not None else None
        if only_wf is not None and only_wf != wf_id:
            return
        tot = self._flow_usage.get(wf_id) if wf_id else None
        if not tot or not (tot["in"] or tot["out"]):
            lbl.setText("")
            return
        lbl.setText(self._fmt_usage(int(tot["in"]), int(tot["out"]),
                                    int(tot["cache"]), float(tot["cost"])))
    def _append_diff(self, title: str, diff: str, log: "ChatView" = None) -> None:
        """Render a before/after diff as a collapsible colored diff bubble."""
        log = log or self.chat_log
        log.add_diff(f"▤ {title}", diff)
        log.scroll_to_bottom()
    def _append_plan(self, steps, log: "ChatView" = None) -> None:
        """Show the plan INLINE in the conversation as an expandable block; update
        the same (per-flow) bubble in place so steps tick off (✓) as they complete."""
        log = log or self.chat_log
        body = _fmt_plan(steps)
        if not body:
            return
        if getattr(log, "_co4e_plan_bubble", None) is None:
            log._co4e_plan_bubble = log.add_plan(body)
        else:
            log._co4e_plan_bubble.set_plain(body)
        log.scroll_to_bottom()