#!/usr/bin/env python3
"""
agent_add.py -- Add new agents with intake gate + wiki ingestion.

Mirror of ``skill_add`` for the agent subject type. Agents live as flat
``.md`` files under ``~/.claude/agents/`` (unlike skills, which each get
their own directory). The flow is therefore shorter:

    validate name -> read content -> intake gate -> copy file ->
    record embedding -> write wiki entity page -> log

Usage
-----
    # Single agent
    python agent_add.py --agent-path /path/to/agent.md --name my-agent \
        --wiki ~/.claude/skill-wiki --agents-dir ~/.claude/agents

    # Batch from directory (every *.md at depth 1 is treated as an agent)
    python agent_add.py --scan-dir /path/to/new-agents/ \
        --wiki ~/.claude/skill-wiki --agents-dir ~/.claude/agents
"""

import argparse
import os
import sys
from datetime import datetime, timezone
from pathlib import Path

from ctx.core.entity_update import build_update_review, render_update_review
from ctx_config import cfg
from ctx.adapters.claude_code.install.install_utils import safe_copy_file
from intake_pipeline import IntakeRejected, check_intake, record_embedding
from wiki_batch_entities import generate_agent_page
from ctx.core.wiki.wiki_queue import enqueue_entity_upsert
from ctx.core.wiki.wiki_packs import (
    load_merged_wiki_pages,
    write_active_wiki_overlay_pack,
)
from ctx.core.wiki.wiki_sync import append_log, ensure_wiki, update_index
from ctx.core.wiki.wiki_utils import validate_skill_name
from ctx.utils._fs_utils import reject_symlink_path, safe_atomic_write_text

TODAY = datetime.now(timezone.utc).strftime("%Y-%m-%d")

# Match skill_add's ceiling — agents are prose, 1 MB is absurdly generous.
_MAX_AGENT_BYTES = 1_048_576


def install_agent(source: Path, agents_dir: Path, name: str) -> Path:
    """Copy agent file into ``agents_dir/<name>.md``.

    Unlike :func:`skill_add.install_skill`, agents are flat single-file
    entries — no per-agent subdirectory.
    """
    dest = agents_dir / f"{name}.md"
    safe_copy_file(source, dest, dest_root=agents_dir)
    return dest


def mirror_agent_body(installed_path: Path, wiki_path: Path, name: str) -> Path:
    """Mirror the installed agent body into the wiki install source tree."""
    mirror_root = wiki_path / "converted-agents"
    dest = mirror_root / f"{name}.md"
    safe_copy_file(installed_path, dest, dest_root=mirror_root)
    return dest


def write_entity_page(wiki_path: Path, name: str, content: str) -> bool:
    """Write agent entity page. Returns True if newly created."""
    relpath = f"entities/agents/{name}.md"
    page = wiki_path / relpath
    packs_dir = wiki_path / "wiki-packs"
    is_new = _read_entity_page_text(wiki_path, name) is None
    if page.exists() or not packs_dir.is_dir():
        reject_symlink_path(page)
        safe_atomic_write_text(page, content, encoding="utf-8")
    if packs_dir.is_dir():
        write_active_wiki_overlay_pack(
            packs_dir=packs_dir,
            pages={relpath: content},
            tombstones=[],
        )
    return is_new


def _read_entity_page_text(wiki_path: Path, name: str) -> str | None:
    relpath = f"entities/agents/{name}.md"
    packs_dir = wiki_path / "wiki-packs"
    if packs_dir.is_dir():
        pages = load_merged_wiki_pages(packs_dir)
        if relpath in pages:
            return pages[relpath]
    entity_page = wiki_path / relpath
    if entity_page.exists():
        return entity_page.read_text(encoding="utf-8", errors="replace")
    return None


def _existing_agent_review_text(wiki_path: Path, name: str, installed_path: Path) -> str:
    existing_page = _read_entity_page_text(wiki_path, name)
    if existing_page is not None:
        existing = existing_page
        if installed_path.exists():
            installed = installed_path.read_text(encoding="utf-8", errors="replace")
            existing += f"\n\n## Installed agent definition\n\n{installed}"
        return existing
    return installed_path.read_text(encoding="utf-8", errors="replace")


def _proposed_agent_review_text(
    *,
    name: str,
    source_path: Path,
    source_content: str,
) -> str:
    page_content = generate_agent_page(name, source_path)
    return f"{page_content}\n\n## Proposed agent definition\n\n{source_content}"


def add_agent(
    *,
    source_path: Path,
    name: str,
    wiki_path: Path,
    agents_dir: Path,
    review_existing: bool = False,
    update_existing: bool = False,
) -> dict:
    """Add a single agent: validate, gate, install, ingest, log.

    Returns a result dict with keys: name, installed, is_new_page.
    """
    validate_skill_name(name)
    reject_symlink_path(source_path)

    file_size = source_path.stat().st_size
    if file_size > _MAX_AGENT_BYTES:
        raise ValueError(
            f"agent file too large ({file_size:,} bytes). Max "
            f"{_MAX_AGENT_BYTES:,}. Trim before ingestion."
        )

    content = source_path.read_text(encoding="utf-8-sig", errors="replace")
    line_count = len(content.splitlines())

    installed_path = agents_dir / f"{name}.md"
    has_existing = (
        installed_path.exists()
        or _read_entity_page_text(wiki_path, name) is not None
    )

    if review_existing and has_existing and not update_existing:
        review = build_update_review(
            entity_type="agent",
            slug=name,
            existing_text=_existing_agent_review_text(wiki_path, name, installed_path),
            proposed_text=_proposed_agent_review_text(
                name=name,
                source_path=source_path,
                source_content=content,
            ),
        )
        return {
            "name": name,
            "installed": str(installed_path),
            "is_new_page": False,
            "skipped": True,
            "update_required": True,
            "update_review": render_update_review(review),
        }

    decision = None
    if not has_existing:
        # Intake gate: reject broken/duplicate agents before we install.
        # Existing updates bypass similarity intake because they compare
        # against their own cached embedding.
        decision = check_intake(content, "agents")
        if not decision.allow:
            raise IntakeRejected(decision)

    # 1. Install into agents-dir.
    installed_path = install_agent(source_path, agents_dir, name)
    mirror_agent_body(installed_path, wiki_path, name)

    # 2. Record embedding. Non-fatal on failure — install already
    # succeeded and a missing vector only weakens the next check.
    try:
        record_embedding(subject_id=name, raw_md=content, subject_type="agents")
    except Exception as exc:  # noqa: BLE001 — cache failure must not break install
        print(
            f"Warning: failed to record intake embedding for {name}: {exc}",
            file=sys.stderr,
        )

    # 3. Write wiki entity page via the shared generator so the agent
    # page layout stays consistent with wiki_batch_entities output.
    page_content = generate_agent_page(name, installed_path)
    is_new = write_entity_page(wiki_path, name, page_content)

    # 4. Index + log.
    if is_new:
        update_index(str(wiki_path), [name], subject_type="agents")

    log_details = [
        f"Source: {source_path}",
        f"Installed: {installed_path}",
        f"Lines: {line_count}",
    ]
    warnings = decision.warnings if decision is not None else ()
    if warnings:
        log_details.append(
            "Warnings: " + "; ".join(f"{w.code}:{w.message}" for w in warnings)
        )
    append_log(str(wiki_path), "add-agent", name, log_details)
    queue_job = enqueue_entity_upsert(
        wiki_path,
        entity_type="agent",
        slug=name,
        entity_path=wiki_path / "entities" / "agents" / f"{name}.md",
        content=page_content,
        action="created" if is_new else "updated",
        source="agent_add",
    )

    return {
        "name": name,
        "installed": str(installed_path),
        "is_new_page": is_new,
        "skipped": False,
        "update_required": False,
        "queued_job_id": queue_job.id,
    }


# ── CLI ───────────────────────────────────────────────────────────────

def main() -> None:
    parser = argparse.ArgumentParser(description="Add new agents with wiki ingestion")
    parser.add_argument("--agent-path", help="Path to a single agent .md to add")
    parser.add_argument("--name", help="Agent name (required with --agent-path)")
    parser.add_argument(
        "--scan-dir",
        help="Directory of agent .md files to batch-add (non-recursive)",
    )
    parser.add_argument(
        "--skip-existing",
        action="store_true",
        help="Skip agents already installed (prevents overwrites)",
    )
    parser.add_argument(
        "--update-existing",
        action="store_true",
        help="Apply the reviewed replacement when an agent already exists",
    )
    parser.add_argument("--wiki", default=str(cfg.wiki_dir), help="Wiki path")
    parser.add_argument(
        "--agents-dir",
        default=str(cfg.agents_dir),
        help="Agents install path",
    )
    args = parser.parse_args()

    wiki_path = Path(os.path.expanduser(args.wiki))
    agents_dir = Path(os.path.expanduser(args.agents_dir))

    ensure_wiki(str(wiki_path))
    agents_dir.mkdir(parents=True, exist_ok=True)

    if args.agent_path and args.scan_dir:
        print("Error: use --agent-path or --scan-dir, not both.", file=sys.stderr)
        sys.exit(1)

    if not args.agent_path and not args.scan_dir:
        print("Error: --agent-path or --scan-dir is required.", file=sys.stderr)
        sys.exit(1)

    candidates: list[tuple[Path, str]] = []

    if args.agent_path:
        if not args.name:
            print("Error: --name is required with --agent-path.", file=sys.stderr)
            sys.exit(1)
        source = Path(os.path.expanduser(args.agent_path))
        if not source.exists():
            print(f"Error: {source} does not exist.", file=sys.stderr)
            sys.exit(1)
        candidates.append((source, args.name))

    if args.scan_dir:
        scan_root = Path(os.path.expanduser(args.scan_dir))
        if not scan_root.exists():
            print(f"Error: {scan_root} does not exist.", file=sys.stderr)
            sys.exit(1)
        # Non-recursive: only top-level *.md files. Nested agents are
        # rare enough that forcing an explicit path is safer than
        # surprise recursion sweeping up unrelated markdown.
        for agent_md in sorted(scan_root.glob("*.md")):
            candidates.append((agent_md, agent_md.stem))

        if not candidates:
            print(f"No agent .md files found under {scan_root}.", file=sys.stderr)
            sys.exit(0)

    added = updated = skipped = rejected = errors = 0
    total = len(candidates)
    for i, (source_path, name) in enumerate(candidates, 1):
        if args.skip_existing and (agents_dir / f"{name}.md").exists():
            skipped += 1
            if skipped <= 5 or skipped % 100 == 0:
                print(f"  [{i}/{total}] [skipped] {name}")
            continue
        try:
            result = add_agent(
                source_path=source_path,
                name=name,
                wiki_path=wiki_path,
                agents_dir=agents_dir,
                review_existing=True,
                update_existing=args.update_existing,
            )
            if result.get("skipped"):
                skipped += 1
                if result.get("update_review"):
                    print(result["update_review"])
                print(f"  [{i}/{total}] [update-review] {name}")
                continue
            if result["is_new_page"]:
                added += 1
                status = "installed"
            else:
                updated += 1
                status = "updated"
            print(f"  [{i}/{total}] [{status}] {name}")
        except IntakeRejected as exc:
            rejected += 1
            codes = ", ".join(f.code for f in exc.decision.failures) or "unknown"
            print(f"  [{i}/{total}] [rejected] {name}: {codes}", file=sys.stderr)
        except Exception as exc:  # noqa: BLE001 — batch CLI must continue past one failure
            errors += 1
            print(f"  [{i}/{total}] ERROR: {name}: {exc}", file=sys.stderr)

    print(
        f"\nDone: {added} added, {updated} updated, {skipped} skipped, "
        f"{rejected} rejected, {errors} errors"
    )
    if rejected or errors:
        sys.exit(1)


if __name__ == "__main__":
    main()