"""Ralph live dashboard endpoints (W3 + dashboard-realtime).

Endpoints:
    GET  /api/ralph/status            — toate proiectele Ralph (cards data)
    GET  /api/ralph/stream            — Server-Sent Events stream (realtime)
    GET  /api/ralph/<slug>/log        — tail progress.txt (default 100 lines)
    GET  /api/ralph/<slug>/prd        — full prd.json content
    POST /api/ralph/<slug>/stop       — SIGTERM la Ralph PID
    POST /api/ralph/<slug>/rollback   — git revert HEAD + decrement last passing story

SSE detail: stream emite `event: status\\ndata: <json>\\n\\n` la schimbări (poll
fişiere la 2s); heartbeat la 30s pentru ca clientul să nu reseze conexiunea.
Necesită ThreadingHTTPServer în api.py — altfel un singur stream blochează tot.

Citește status din `~/workspace/<slug>/scripts/ralph/`:
- prd.json        → stories (passes/failed/blocked/retries)
- progress.txt    → log human-readable
- logs/iteration-*.log → mtime ultimului iter
- .ralph.pid      → PID activ (verificat cu os.kill 0)

Reuse path constants din `dashboard/constants.py` (WORKSPACE_DIR).
"""
import json
import os
import re
import signal
import subprocess
import time
from datetime import datetime
from pathlib import Path

import constants


# Slug strict: alphanum + dash + underscore, max 64 chars. Reject path traversal explicit.
_SLUG_RE = re.compile(r"^[A-Za-z0-9_-]{1,64}$")


# Path Ralph per proiect (mereu în scripts/ralph/)
def _ralph_dir(project_dir: Path) -> Path:
    return project_dir / "scripts" / "ralph"


# Estimare ETA simplistă: avg iter time × stories rămase
DEFAULT_ITER_MINUTES = 12  # midpoint din intervalul 8-15min menționat în plan


class RalphHandlers:
    """Mixin pentru /api/ralph/* — Ralph live status + control."""

    # ── helpers ────────────────────────────────────────────────
    def _ralph_validate_slug(self, slug: str):
        """Validează slug-ul + returnează project_dir sau None.

        Strict: alphanum + dash + underscore, ≤64 chars. Path traversal sequences
        (`..`, `/`, `\\`) sau caractere ne-alfanumerice sunt respinse înainte de
        orice atingere a filesystem-ului.
        """
        if not slug:
            return None
        # Defense-in-depth: explicit path-traversal/separator reject (regex îl
        # acoperă, dar îl ţinem explicit ca safety net dacă regex-ul se relaxează).
        if ".." in slug or "/" in slug or "\\" in slug:
            return None
        if not _SLUG_RE.match(slug):
            return None
        project_dir = constants.WORKSPACE_DIR / slug
        try:
            resolved = project_dir.resolve()
            workspace_resolved = constants.WORKSPACE_DIR.resolve()
            resolved.relative_to(workspace_resolved)
        except (ValueError, OSError):
            return None
        if not project_dir.exists() or not project_dir.is_dir():
            return None
        return project_dir

    def _ralph_pid_alive(self, ralph_dir: Path):
        """Întoarce (running: bool, pid: int|None)."""
        pid_file = ralph_dir / ".ralph.pid"
        if not pid_file.exists():
            return False, None
        try:
            pid = int(pid_file.read_text().strip())
            os.kill(pid, 0)  # signal 0 = check existence
            return True, pid
        except (ValueError, ProcessLookupError, PermissionError, OSError):
            return False, None

    def _ralph_eta_minutes(self, stories_remaining: int, last_iter_mtime: float | None) -> int | None:
        """Estimează minute rămase — None dacă nu avem date."""
        if stories_remaining <= 0:
            return 0
        return stories_remaining * DEFAULT_ITER_MINUTES

    def _ralph_summarize_project(self, project_dir: Path) -> dict | None:
        """Construiește dict de status per proiect — None dacă nu e Ralph project."""
        ralph_dir = _ralph_dir(project_dir)
        prd_json = ralph_dir / "prd.json"
        if not prd_json.exists():
            return None

        # Defensive parse — corupt prd.json nu trebuie să dărâme dashboard
        try:
            prd = json.loads(prd_json.read_text(encoding="utf-8"))
        except (json.JSONDecodeError, OSError):
            return {
                "slug": project_dir.name,
                "status": "error",
                "error": "prd.json invalid sau ilizibil",
                "running": False,
                "pid": None,
                "stories": [],
                "storiesTotal": 0,
                "storiesComplete": 0,
                "storiesFailed": 0,
                "storiesBlocked": 0,
            }

        stories = prd.get("userStories", []) or []
        total = len(stories)
        complete = sum(1 for s in stories if s.get("passes"))
        failed = sum(1 for s in stories if s.get("failed"))
        blocked = sum(1 for s in stories if s.get("blocked"))
        remaining = total - complete - failed - blocked

        running, pid = self._ralph_pid_alive(ralph_dir)

        # Last iteration mtime (pentru "acum X")
        logs_dir = ralph_dir / "logs"
        last_iter_mtime = None
        last_iter_iso = None
        if logs_dir.exists():
            iter_logs = sorted(logs_dir.glob("iteration-*.log"), key=lambda f: f.stat().st_mtime, reverse=True)
            if iter_logs:
                last_iter_mtime = iter_logs[0].stat().st_mtime
                last_iter_iso = datetime.fromtimestamp(last_iter_mtime).isoformat()

        # Status compus pentru UI cards
        if running:
            top_status = "running"
        elif failed > 0 and remaining == 0:
            top_status = "failed"
        elif complete == total and total > 0:
            top_status = "complete"
        elif blocked > 0 and running is False:
            top_status = "blocked"
        else:
            top_status = "idle"

        # Current story (DAG-eligible cel mai mic priority)
        current_story = None
        if running:
            eligible = [
                s for s in stories
                if not s.get("passes") and not s.get("failed") and not s.get("blocked")
            ]
            eligible.sort(key=lambda s: (s.get("priority", 999), s.get("id", "")))
            if eligible:
                current_story = {
                    "id": eligible[0].get("id"),
                    "title": eligible[0].get("title"),
                    "tags": eligible[0].get("tags", []),
                    "retries": eligible[0].get("retries", 0),
                }

        return {
            "slug": project_dir.name,
            "status": top_status,
            "running": running,
            "pid": pid,
            "branchName": prd.get("branchName", ""),
            "storiesTotal": total,
            "storiesComplete": complete,
            "storiesFailed": failed,
            "storiesBlocked": blocked,
            "storiesRemaining": remaining,
            "currentStory": current_story,
            "lastIterAt": last_iter_iso,
            "etaMinutes": self._ralph_eta_minutes(remaining, last_iter_mtime),
            "stories": [
                {
                    "id": s.get("id"),
                    "title": s.get("title"),
                    "passes": bool(s.get("passes")),
                    "failed": bool(s.get("failed")),
                    "blocked": bool(s.get("blocked")),
                    "retries": int(s.get("retries", 0)),
                    "tags": s.get("tags", []),
                    "failureReason": s.get("failureReason", ""),
                }
                for s in stories
            ],
        }

    def _ralph_collect_status(self) -> dict:
        """Construieşte payload-ul de status pentru toate proiectele.

        Folosit de `/api/ralph/status` (GET single-shot) şi de `/api/ralph/stream`
        (SSE — emis la schimbări).
        """
        projects: list[dict] = []
        if constants.WORKSPACE_DIR.exists():
            for entry in sorted(constants.WORKSPACE_DIR.iterdir()):
                if not entry.is_dir() or entry.name.startswith("."):
                    continue
                summary = self._ralph_summarize_project(entry)
                if summary is not None:
                    projects.append(summary)
        return {
            "projects": projects,
            "fetchedAt": datetime.now().isoformat(),
            "count": len(projects),
        }

    def _ralph_signature(self, snapshot: dict) -> tuple:
        """Compactă semnătură pentru change-detection în SSE — doar fields care
        contează pentru UI (status, counts, current story). Timestamps de iter
        au granularitate de second pentru a evita flicker pe nanosecond drift.
        """
        sig: list[tuple] = []
        for p in snapshot.get("projects", []) or []:
            cs = p.get("currentStory") or {}
            sig.append((
                p.get("slug"),
                p.get("status"),
                bool(p.get("running")),
                p.get("storiesTotal"),
                p.get("storiesComplete"),
                p.get("storiesFailed"),
                p.get("storiesBlocked"),
                p.get("lastIterAt"),
                cs.get("id"),
                cs.get("retries"),
            ))
        return tuple(sorted(sig, key=lambda t: t[0] or ""))

    # ── /api/ralph/status (GET) ────────────────────────────────
    def handle_ralph_status(self):
        """Întoarce status pentru toate proiectele Ralph din workspace."""
        try:
            self.send_json(self._ralph_collect_status())
        except Exception as exc:
            self.send_json({"error": str(exc)}, 500)

    # ── /api/ralph/stream (GET, SSE) ───────────────────────────
    def handle_ralph_stream(self):
        """Server-Sent Events: emite snapshot la schimbări (poll fişiere 2s).

        Heartbeat la 30s pentru a evita timeout pe proxy-uri. Loop-ul iese
        curat la BrokenPipe (clientul închis tab-ul). Necesită
        ThreadingHTTPServer în api.py — altfel blochează toate request-urile.
        """
        try:
            self.send_response(200)
            self.send_header("Content-Type", "text/event-stream")
            self.send_header("Cache-Control", "no-cache")
            self.send_header("Connection", "keep-alive")
            # Disable proxy buffering (nginx/cloudflare) — flush imediat
            self.send_header("X-Accel-Buffering", "no")
            self.send_header("Access-Control-Allow-Origin", "*")
            self.end_headers()
        except (BrokenPipeError, ConnectionResetError):
            return

        last_signature: tuple | None = None
        last_heartbeat = time.monotonic()

        # Initial snapshot — clientul nu aşteaptă primul change
        try:
            snapshot = self._ralph_collect_status()
            last_signature = self._ralph_signature(snapshot)
            payload = json.dumps(snapshot).encode("utf-8")
            self.wfile.write(b"event: status\ndata: " + payload + b"\n\n")
            self.wfile.flush()
        except (BrokenPipeError, ConnectionResetError):
            return
        except Exception as exc:
            try:
                err = json.dumps({"error": str(exc)}).encode("utf-8")
                self.wfile.write(b"event: error\ndata: " + err + b"\n\n")
                self.wfile.flush()
            except Exception:
                pass
            return

        # Stream loop
        while True:
            try:
                time.sleep(2)
                snapshot = self._ralph_collect_status()
                signature = self._ralph_signature(snapshot)
                now = time.monotonic()
                if signature != last_signature:
                    payload = json.dumps(snapshot).encode("utf-8")
                    self.wfile.write(b"event: status\ndata: " + payload + b"\n\n")
                    self.wfile.flush()
                    last_signature = signature
                    last_heartbeat = now
                elif now - last_heartbeat >= 30:
                    self.wfile.write(b"event: heartbeat\ndata: {}\n\n")
                    self.wfile.flush()
                    last_heartbeat = now
            except (BrokenPipeError, ConnectionResetError):
                return
            except Exception:
                # Best-effort: o iteraţie eşuată nu trebuie să termine stream-ul,
                # dar dacă socketul e mort BrokenPipe va prinde next loop.
                continue

    # ── /api/ralph/<slug>/log (GET) ────────────────────────────
    def handle_ralph_log(self, slug: str):
        """Tail progress.txt pentru un slug. Default last 100 lines."""
        try:
            project_dir = self._ralph_validate_slug(slug)
            if not project_dir:
                self.send_json({"error": "Invalid project slug"}, 400)
                return

            from urllib.parse import parse_qs, urlparse
            qs = parse_qs(urlparse(self.path).query)
            try:
                lines_n = min(int(qs.get("lines", ["100"])[0]), 1000)
            except ValueError:
                lines_n = 100

            progress = _ralph_dir(project_dir) / "progress.txt"
            if not progress.exists():
                self.send_json({"slug": slug, "lines": [], "total": 0})
                return

            try:
                content = progress.read_text(encoding="utf-8", errors="replace")
            except OSError as exc:
                self.send_json({"error": f"read failed: {exc}"}, 500)
                return

            all_lines = content.splitlines()
            tail = all_lines[-lines_n:] if len(all_lines) > lines_n else all_lines
            self.send_json({
                "slug": slug,
                "lines": tail,
                "total": len(all_lines),
            })
        except Exception as exc:
            self.send_json({"error": str(exc)}, 500)

    # ── /api/ralph/<slug>/prd (GET) ────────────────────────────
    def handle_ralph_prd(self, slug: str):
        """Returnează full prd.json pentru un slug."""
        try:
            project_dir = self._ralph_validate_slug(slug)
            if not project_dir:
                self.send_json({"error": "Invalid project slug"}, 400)
                return

            prd_json = _ralph_dir(project_dir) / "prd.json"
            if not prd_json.exists():
                self.send_json({"error": "prd.json not found"}, 404)
                return

            try:
                data = json.loads(prd_json.read_text(encoding="utf-8"))
            except json.JSONDecodeError as exc:
                self.send_json({"error": f"prd.json invalid: {exc}"}, 500)
                return

            self.send_json(data)
        except Exception as exc:
            self.send_json({"error": str(exc)}, 500)

    # ── /api/ralph/<slug>/stop (POST) ──────────────────────────
    def handle_ralph_stop(self, slug: str):
        """Trimite SIGTERM la Ralph PID. Verifică că PID-ul e în WORKSPACE_DIR."""
        try:
            project_dir = self._ralph_validate_slug(slug)
            if not project_dir:
                self.send_json({"success": False, "error": "Invalid project slug"}, 400)
                return

            ralph_dir = _ralph_dir(project_dir)
            pid_file = ralph_dir / ".ralph.pid"
            if not pid_file.exists():
                self.send_json({"success": False, "error": "No PID file"}, 404)
                return

            try:
                pid = int(pid_file.read_text().strip())
            except (ValueError, OSError) as exc:
                self.send_json({"success": False, "error": f"Invalid PID file: {exc}"}, 500)
                return

            # Sandbox: verifică că procesul e în workspace (nu omoară random PID)
            try:
                proc_cwd = Path(f"/proc/{pid}/cwd").resolve()
                if not str(proc_cwd).startswith(str(constants.WORKSPACE_DIR)):
                    self.send_json({"success": False, "error": "PID not in workspace"}, 403)
                    return
            except (FileNotFoundError, PermissionError):
                # Procesul nu mai există — best-effort cleanup
                self.send_json({"success": True, "message": "Process already stopped"})
                return

            try:
                os.killpg(os.getpgid(pid), signal.SIGTERM)
            except ProcessLookupError:
                self.send_json({"success": True, "message": "Process already stopped"})
                return
            except PermissionError:
                self.send_json({"success": False, "error": "Permission denied"}, 403)
                return

            self.send_json({"success": True, "message": f"Ralph stopped (PID {pid})"})
        except Exception as exc:
            self.send_json({"success": False, "error": str(exc)}, 500)

    # ── /api/ralph/<slug>/rollback (POST) ──────────────────────
    def _ralph_decrement_last_pass(self, project_dir: Path) -> str | None:
        """Marchează ultima story `passes=True` (din ordinea din prd.json) ca
        incompletă (`passes=False`, şterge `failed`/`blocked`/`failureReason`,
        retries=0). Atomic write (temp + rename). Întoarce id-ul story-ului
        sau None dacă nu există nimic de decrementat / prd.json invalid.
        """
        prd_path = _ralph_dir(project_dir) / "prd.json"
        if not prd_path.exists():
            return None
        try:
            prd = json.loads(prd_path.read_text(encoding="utf-8"))
        except (json.JSONDecodeError, OSError):
            return None
        stories = prd.get("userStories", []) or []
        target_idx: int | None = None
        # ultima poziţională cu passes=True (DAG-order = ordine de finalizare)
        for i in range(len(stories) - 1, -1, -1):
            if stories[i].get("passes"):
                target_idx = i
                break
        if target_idx is None:
            return None
        story_id = stories[target_idx].get("id")
        stories[target_idx]["passes"] = False
        # Reset stare derivată — story-ul e disponibil pentru re-run
        stories[target_idx].pop("failed", None)
        stories[target_idx].pop("blocked", None)
        stories[target_idx].pop("failureReason", None)
        stories[target_idx]["retries"] = 0
        # Atomic write (acelaşi pattern ca W3 ralph_dag.py)
        tmp = prd_path.with_suffix(".json.tmp")
        try:
            tmp.write_text(json.dumps(prd, indent=2), encoding="utf-8")
            tmp.replace(prd_path)
        except OSError:
            tmp.unlink(missing_ok=True)
            return None
        return story_id

    def handle_ralph_rollback(self, slug: str):
        """Rollback ultimul commit într-un proiect Ralph.

        Strategy: `git revert --no-edit HEAD` (history-preserving). Fallback la
        `git reset --hard HEAD~1` doar dacă revert eşuează (conflict, binary
        file). După succes, decrementează `passes` pe ultima story marcată
        complete în prd.json (atomic write).

        Returns: `{success, message, reverted_commit, story_reverted, method}`.
        """
        try:
            project_dir = self._ralph_validate_slug(slug)
            if not project_dir:
                self.send_json({
                    "success": False,
                    "message": "Invalid project slug",
                    "reverted_commit": None,
                    "story_reverted": None,
                }, 400)
                return

            git_dir = project_dir / ".git"
            if not git_dir.exists():
                self.send_json({
                    "success": False,
                    "message": "Not a git repository",
                    "reverted_commit": None,
                    "story_reverted": None,
                }, 400)
                return

            # Read HEAD before any operation (raportăm SHA-ul afectat)
            head_proc = subprocess.run(
                ["git", "rev-parse", "HEAD"],
                cwd=str(project_dir), capture_output=True, text=True, timeout=10,
            )
            if head_proc.returncode != 0:
                self.send_json({
                    "success": False,
                    "message": f"git rev-parse HEAD failed: {head_proc.stderr.strip()}",
                    "reverted_commit": None,
                    "story_reverted": None,
                }, 500)
                return
            commit_to_revert = head_proc.stdout.strip()

            # Try revert (preserves history, recommended)
            method = "revert"
            revert = subprocess.run(
                ["git", "revert", "--no-edit", "HEAD"],
                cwd=str(project_dir), capture_output=True, text=True, timeout=30,
            )
            if revert.returncode != 0:
                # Conflict / binary file — abort & fall back to reset --hard
                subprocess.run(
                    ["git", "revert", "--abort"],
                    cwd=str(project_dir), capture_output=True, timeout=10,
                )
                reset = subprocess.run(
                    ["git", "reset", "--hard", "HEAD~1"],
                    cwd=str(project_dir), capture_output=True, text=True, timeout=30,
                )
                if reset.returncode != 0:
                    self.send_json({
                        "success": False,
                        "message": (
                            f"revert failed ({revert.stderr.strip()[:200]}), "
                            f"reset failed ({reset.stderr.strip()[:200]})"
                        ),
                        "reverted_commit": commit_to_revert,
                        "story_reverted": None,
                    }, 500)
                    return
                method = "reset"

            # Best-effort: decrement story passes (nu fail dacă lipseşte prd.json)
            story_reverted = self._ralph_decrement_last_pass(project_dir)

            short_sha = commit_to_revert[:8]
            msg_bits = [f"Rolled back {short_sha} via git {method}"]
            if story_reverted:
                msg_bits.append(f"story {story_reverted} marked incomplete")
            self.send_json({
                "success": True,
                "message": "; ".join(msg_bits),
                "reverted_commit": commit_to_revert,
                "story_reverted": story_reverted,
                "method": method,
            })
        except subprocess.TimeoutExpired:
            self.send_json({
                "success": False,
                "message": "git operation timed out",
                "reverted_commit": None,
                "story_reverted": None,
            }, 500)
        except Exception as exc:
            self.send_json({
                "success": False,
                "message": str(exc),
                "reverted_commit": None,
                "story_reverted": None,
            }, 500)