"""
File read/write/search tools — two access scopes.

  Project scope (no admin required):
    project_file_read   — read a file with optional line-range (offset)
    project_file_list   — list a directory with sizes + timestamps
    file_stat           — size, modified time, line count for a path
    file_grep           — regex search with context lines; up to 50 matches
    file_syntax_check   — py_compile (.py) or json.loads (.json) check

  System scope (admin-only):
    file_read           — read a file from ~/agents_sync/, ~/OSIT_dev/, etc.
    file_list           — list a directory (same roots)
    file_write          — write/append (~/agents_sync/ + Cortex home/)

  Session tools (user-level, persona-isolated):
    session_read        — read a session log by date
    session_search      — keyword search across session logs

All project-scope tools are restricted to the Cortex project root:
  ~/agents_sync/projects/Cortex_and_Inara_dev/
"""

import asyncio
import json
import logging
import re
import subprocess
from datetime import datetime
from pathlib import Path

from google.genai import types

logger = logging.getLogger(__name__)

# ── Access roots ──────────────────────────────────────────────────────────────

# Project root: two levels up from cortex/tools/files.py → Cortex_and_Inara_dev/
_PROJECT_ROOT: Path = Path(__file__).parent.parent.parent.resolve()

# System-wide read roots
def _build_allowed_roots() -> list[Path]:
    roots = [
        Path.home() / "agents_sync",
        Path.home() / "OSIT_dev",
        Path.home() / "DgrZone_Nextcloud",
        Path.home() / "OSIT_Nextcloud",
    ]
    try:
        from config import settings
        roots.append(settings.home_root())
    except Exception:
        pass
    return roots

_ALLOWED_ROOTS: list[Path] = _build_allowed_roots()

# Write is tighter
_WRITE_ROOTS: list[Path] = [Path.home() / "agents_sync"]

# Size limits
_MAX_BYTES  = 50_000
_MAX_LINES  = 500
_MAX_GREP_MATCHES = 50


def _is_project_allowed(resolved: Path) -> bool:
    try:
        resolved.relative_to(_PROJECT_ROOT)
        return True
    except ValueError:
        return False


def _is_allowed(resolved: Path) -> bool:
    for root in _ALLOWED_ROOTS:
        try:
            resolved.relative_to(root)
            return True
        except ValueError:
            continue
    return False


def _is_write_allowed(resolved: Path) -> bool:
    for root in _WRITE_ROOTS:
        try:
            resolved.relative_to(root)
            return True
        except ValueError:
            continue
    try:
        from config import settings
        resolved.relative_to(settings.home_root())
        return True
    except (ValueError, Exception):
        pass
    return False


# ── Shared implementations ────────────────────────────────────────────────────

def _read_impl(path_str: str, offset: int | None, max_lines: int | None, is_allowed_fn) -> str:
    try:
        resolved = Path(path_str).expanduser().resolve()
    except Exception as e:
        return f"Invalid path: {e}"

    if not is_allowed_fn(resolved):
        return f"Access denied: {resolved}"

    if not resolved.exists():
        return f"File not found: {resolved}"

    if not resolved.is_file():
        try:
            entries = sorted(resolved.iterdir())
            names = [e.name + ("/" if e.is_dir() else "") for e in entries[:100]]
            return f"Directory listing for {resolved}:\n" + "\n".join(names)
        except Exception as e:
            return f"Cannot list directory: {e}"

    try:
        raw = resolved.read_bytes()
    except Exception as e:
        return f"Read error: {e}"

    try:
        text = raw.decode("utf-8")
    except UnicodeDecodeError:
        return f"Binary file (not readable as text): {resolved}  [{len(raw)} bytes]"

    all_lines = text.splitlines()
    total = len(all_lines)

    # offset is 1-based; default = start of file
    start = max(0, (offset or 1) - 1)
    working = all_lines[start:]

    limit = min(max_lines or _MAX_LINES, _MAX_LINES)
    truncated = False
    if len(working) > limit:
        working = working[:limit]
        truncated = True

    result = "\n".join(working)
    if len(result) > _MAX_BYTES:
        result = result[:_MAX_BYTES]
        truncated = True

    end_line = start + len(working)
    header = f"[Lines {start + 1}–{end_line} of {total}]\n" if (start > 0 or truncated) else ""
    trailer = f"\n\n… [truncated — file has {total} lines; use offset={end_line + 1} to read more]" if truncated else ""

    return header + result + trailer


def _list_impl(path_str: str, is_allowed_fn) -> str:
    try:
        resolved = Path(path_str).expanduser().resolve()
    except Exception as e:
        return f"Invalid path: {e}"

    if not is_allowed_fn(resolved):
        return f"Access denied: {resolved}"

    if not resolved.exists():
        return f"Path not found: {resolved}"

    if resolved.is_file():
        return f"{resolved} is a file. Use file_read / project_file_read to read it."

    try:
        entries = sorted(resolved.iterdir(), key=lambda e: (e.is_file(), e.name.lower()))
        lines = []
        for e in entries[:200]:
            if e.is_dir():
                suffix = "/"
            else:
                try:
                    st = e.stat()
                    mtime = datetime.fromtimestamp(st.st_mtime).strftime("%Y-%m-%d %H:%M")
                    suffix = f"  ({st.st_size:,} B, {mtime})"
                except Exception:
                    suffix = ""
            lines.append(f"{e.name}{suffix}")
        result = "\n".join(lines)
        if len(entries) > 200:
            result += f"\n… ({len(entries) - 200} more not shown)"
        return f"Contents of {resolved}:\n\n{result}"
    except Exception as e:
        return f"Cannot list directory: {e}"


# ── Project-scoped tools ──────────────────────────────────────────────────────

async def project_file_read(path: str, offset: int | None = None, max_lines: int | None = None) -> str:
    """Read a file within the Cortex project directory, with optional line range."""
    return await asyncio.to_thread(_read_impl, path, offset, max_lines, _is_project_allowed)


async def project_file_list(path: str) -> str:
    """List directory contents within the Cortex project directory, with sizes and timestamps."""
    return await asyncio.to_thread(_list_impl, path, _is_project_allowed)


async def file_stat(path: str) -> str:
    """Return metadata for a file or directory: type, size, modified time, line count."""
    return await asyncio.to_thread(_sync_file_stat, path)


def _sync_file_stat(path_str: str) -> str:
    try:
        resolved = Path(path_str).expanduser().resolve()
    except Exception as e:
        return f"Invalid path: {e}"

    if not _is_project_allowed(resolved):
        return f"Access denied: {resolved}\nProject root: {_PROJECT_ROOT}"

    if not resolved.exists():
        return f"Path not found: {resolved}"

    try:
        st = resolved.stat()
    except Exception as e:
        return f"Cannot stat: {e}"

    modified = datetime.fromtimestamp(st.st_mtime).strftime("%Y-%m-%d %H:%M:%S")
    lines = [
        f"Path:     {resolved}",
        f"Type:     {'directory' if resolved.is_dir() else 'file'}",
        f"Size:     {st.st_size:,} bytes",
        f"Modified: {modified}",
    ]

    if resolved.is_file():
        try:
            raw = resolved.read_bytes()
            if b'\x00' not in raw[:1024]:
                lines.append(f"Lines:    {len(raw.decode('utf-8', errors='replace').splitlines())}")
        except Exception:
            pass
    elif resolved.is_dir():
        try:
            entries = list(resolved.iterdir())
            n_files = sum(1 for e in entries if e.is_file())
            n_dirs  = sum(1 for e in entries if e.is_dir())
            lines.append(f"Contents: {n_files} file(s), {n_dirs} subdirector{'y' if n_dirs == 1 else 'ies'}")
        except Exception:
            pass

    return "\n".join(lines)


async def file_grep(path: str, pattern: str, context_lines: int = 2, recursive: bool = True) -> str:
    """Search for a regex pattern in a file or directory, returning matching lines with context."""
    return await asyncio.to_thread(_sync_file_grep, path, pattern, context_lines, recursive)


def _sync_file_grep(path_str: str, pattern: str, context_lines: int, recursive: bool) -> str:
    try:
        resolved = Path(path_str).expanduser().resolve()
    except Exception as e:
        return f"Invalid path: {e}"

    if not _is_project_allowed(resolved):
        return f"Access denied: {resolved}\nProject root: {_PROJECT_ROOT}"

    if not resolved.exists():
        return f"Path not found: {resolved}"

    try:
        regex = re.compile(pattern, re.IGNORECASE)
    except re.error as e:
        return f"Invalid regex pattern: {e}"

    ctx = max(0, min(context_lines, 5))

    if resolved.is_file():
        files_to_search = [resolved]
    elif recursive:
        files_to_search = sorted(f for f in resolved.rglob("*") if f.is_file())
    else:
        files_to_search = sorted(f for f in resolved.iterdir() if f.is_file())

    total_matches = 0
    sections: list[str] = []
    capped = False

    for fp in files_to_search:
        if total_matches >= _MAX_GREP_MATCHES:
            capped = True
            break
        try:
            raw = fp.read_bytes()
        except OSError:
            continue
        if b'\x00' in raw[:1024]:
            continue  # skip binary
        try:
            text = raw.decode("utf-8", errors="replace")
        except Exception:
            continue

        file_lines = text.splitlines()
        match_indices = [i for i, line in enumerate(file_lines) if regex.search(line)]
        if not match_indices:
            continue

        total_matches += len(match_indices)

        try:
            label = str(fp.relative_to(_PROJECT_ROOT))
        except ValueError:
            label = str(fp)

        file_output = [f"── {label} ──"]
        printed: set[int] = set()

        for mi in match_indices:
            start = max(0, mi - ctx)
            end   = min(len(file_lines), mi + ctx + 1)
            if printed and start > max(printed) + 1:
                file_output.append("  ···")
            for j in range(start, end):
                if j not in printed:
                    marker = "►" if j == mi else " "
                    file_output.append(f"  {j + 1:4d}{marker} {file_lines[j]}")
                    printed.add(j)

        sections.append("\n".join(file_output))

    if not sections:
        return f"No matches for '{pattern}' in {resolved}"

    cap_note = f" (capped at {_MAX_GREP_MATCHES})" if capped else ""
    header   = f"grep '{pattern}' — {total_matches} match(es){cap_note}:"
    return header + "\n\n" + "\n\n".join(sections)


async def file_syntax_check(path: str) -> str:
    """Check syntax of a Python (.py) or JSON (.json) file."""
    return await asyncio.to_thread(_sync_file_syntax_check, path)


def _sync_file_syntax_check(path_str: str) -> str:
    try:
        resolved = Path(path_str).expanduser().resolve()
    except Exception as e:
        return f"Invalid path: {e}"

    if not _is_project_allowed(resolved):
        return f"Access denied: {resolved}\nProject root: {_PROJECT_ROOT}"

    if not resolved.exists():
        return f"File not found: {resolved}"

    if not resolved.is_file():
        return f"Not a file: {resolved}"

    suffix = resolved.suffix.lower()

    if suffix == ".py":
        try:
            result = subprocess.run(
                ["python3", "-m", "py_compile", str(resolved)],
                capture_output=True, text=True, timeout=15,
            )
            if result.returncode == 0:
                return f"OK — {resolved.name}: syntax valid"
            err = (result.stderr or result.stdout).strip()
            return f"Syntax error in {resolved.name}:\n{err}"
        except subprocess.TimeoutExpired:
            return f"Timeout running py_compile on {resolved.name}"
        except Exception as e:
            return f"Error: {e}"

    elif suffix == ".json":
        try:
            text = resolved.read_text(encoding="utf-8")
            json.loads(text)
            return f"OK — {resolved.name}: valid JSON"
        except json.JSONDecodeError as e:
            return f"JSON error in {resolved.name}: {e}"
        except Exception as e:
            return f"Error reading {resolved.name}: {e}"

    else:
        return f"Syntax check not supported for '{suffix}' files. Supported: .py, .json"


# ── System-scoped tools ───────────────────────────────────────────────────────

async def file_read(path: str, offset: int | None = None, max_lines: int | None = None) -> str:
    """Read a local file from the broader system. Allowed: ~/agents_sync/, ~/OSIT_dev/, etc. ADMIN ONLY."""
    return await asyncio.to_thread(_read_impl, path, offset, max_lines, _is_allowed)


async def file_list(path: str) -> str:
    """List directory contents from the broader system. ADMIN ONLY."""
    return await asyncio.to_thread(_list_impl, path, _is_allowed)


async def file_write(path: str, content: str, mode: str = "overwrite") -> str:
    """Write or append content to a file. Write roots: ~/agents_sync/ and Cortex home/. ADMIN ONLY."""
    return await asyncio.to_thread(_sync_file_write, path, content, mode)


def _sync_file_write(path: str, content: str, mode: str) -> str:
    try:
        resolved = Path(path).expanduser().resolve()
    except Exception as e:
        return f"Invalid path: {e}"

    if not _is_write_allowed(resolved):
        return (
            f"Write access denied: {resolved}\n"
            f"Allowed write roots: ~/agents_sync/ and the Cortex home/ directory."
        )

    if mode not in ("overwrite", "append"):
        return f"Invalid mode '{mode}' — use 'overwrite' or 'append'."

    try:
        resolved.parent.mkdir(parents=True, exist_ok=True)
        if mode == "append":
            with resolved.open("a", encoding="utf-8") as f:
                f.write(content)
            return f"Appended {len(content)} chars to {resolved}"
        else:
            resolved.write_text(content, encoding="utf-8")
            return f"Wrote {len(content)} chars to {resolved}"
    except Exception as e:
        logger.error("file_write error for %s: %s", resolved, e)
        return f"Write error: {e}"


# ── Session tools ─────────────────────────────────────────────────────────────

_SEARCH_EXCERPT_CHARS = 150


async def session_read(date: str) -> str:
    """Read a full session log by date (YYYY-MM-DD)."""
    return await asyncio.to_thread(_sync_session_read, date.strip())


def _sync_session_read(date: str) -> str:
    from persona import persona_path
    sessions_dir = persona_path() / "sessions"
    if not sessions_dir.exists():
        return "No session logs found."

    target = sessions_dir / f"{date}.md"
    if target.exists():
        content = target.read_text()
        return f"Session log for {date} ({len(content)} chars):\n\n{content}"

    available = sorted([f.stem for f in sessions_dir.glob("*.md")], reverse=True)
    if not available:
        return "No session logs found."
    recent = "\n".join(f"  {d}" for d in available[:15])
    return f"No session log found for '{date}'. Available dates (most recent first):\n{recent}"


async def session_search(query: str, limit: int = 5) -> str:
    """Search past session logs for a keyword or phrase."""
    return await asyncio.to_thread(_sync_session_search, query, limit)


def _sync_session_search(query: str, limit: int) -> str:
    from persona import persona_path
    sessions_dir = persona_path() / "sessions"
    if not sessions_dir.exists():
        return "No session logs found."

    limit   = max(1, min(limit, 20))
    pattern = re.compile(re.escape(query), re.IGNORECASE)
    session_files = sorted(sessions_dir.glob("*.md"), reverse=True)

    matches = []
    for sf in session_files:
        if len(matches) >= limit:
            break
        try:
            text = sf.read_text()
        except OSError:
            continue
        for m in pattern.finditer(text):
            if len(matches) >= limit:
                break
            start   = max(0, m.start() - _SEARCH_EXCERPT_CHARS)
            end     = min(len(text), m.end() + _SEARCH_EXCERPT_CHARS)
            excerpt = text[start:end].strip()
            if start > 0:
                excerpt = "…" + excerpt
            if end < len(text):
                excerpt = excerpt + "…"
            matches.append(f"[{sf.stem}] {excerpt}")

    if not matches:
        return f"No matches for '{query}' across {len(session_files)} session logs."
    header = f"Session search: '{query}' — {len(matches)} match(es) across {len(session_files)} logs\n"
    return header + "\n\n".join(matches)


# ── Declarations ──────────────────────────────────────────────────────────────

DECLARATIONS = [
    # Project-scoped
    types.FunctionDeclaration(
        name="project_file_read",
        description=(
            "Read a file within the Cortex project directory (source code, docs, config, persona files). "
            "Supports reading a specific line range via offset — use to page through large files "
            "without re-reading from the top. If given a directory path, returns a listing instead. "
            "Project root: ~/agents_sync/projects/Cortex_and_Inara_dev/"
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "path": types.Schema(
                    type=types.Type.STRING,
                    description="Absolute or ~/... path to the file",
                ),
                "offset": types.Schema(
                    type=types.Type.INTEGER,
                    description="Start reading from this line number (1-based). Omit to read from the top.",
                ),
                "max_lines": types.Schema(
                    type=types.Type.INTEGER,
                    description="Maximum lines to return (default 500)",
                ),
            },
            required=["path"],
        ),
    ),
    types.FunctionDeclaration(
        name="project_file_list",
        description=(
            "List files and subdirectories within the Cortex project directory. "
            "Shows file sizes and modified timestamps. "
            "Project root: ~/agents_sync/projects/Cortex_and_Inara_dev/"
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "path": types.Schema(
                    type=types.Type.STRING,
                    description="Absolute or ~/... path to the directory",
                ),
            },
            required=["path"],
        ),
    ),
    types.FunctionDeclaration(
        name="file_stat",
        description=(
            "Get metadata for a file or directory: type, size, modified timestamp, line count (for text files) "
            "or entry counts (for directories). Use before reading to check recency or size. "
            "Restricted to the Cortex project directory."
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "path": types.Schema(
                    type=types.Type.STRING,
                    description="Absolute or ~/... path to the file or directory",
                ),
            },
            required=["path"],
        ),
    ),
    types.FunctionDeclaration(
        name="file_grep",
        description=(
            "Search for a regex pattern in a file or directory, returning matching lines with surrounding "
            "context. Much more efficient than reading an entire source file — use this to find function "
            "definitions, variable names, TODO comments, imports, error strings, etc. "
            "Searches recursively by default. Capped at 50 matches. Skips binary files. "
            "Case-insensitive. Restricted to the Cortex project directory."
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "path": types.Schema(
                    type=types.Type.STRING,
                    description="File or directory to search (e.g. ~/agents_sync/projects/Cortex_and_Inara_dev/cortex/)",
                ),
                "pattern": types.Schema(
                    type=types.Type.STRING,
                    description="Regex pattern to search for (case-insensitive). Examples: 'def ha_', 'import httpx', 'TODO'",
                ),
                "context_lines": types.Schema(
                    type=types.Type.INTEGER,
                    description="Lines of context before/after each match (default 2, max 5)",
                ),
                "recursive": types.Schema(
                    type=types.Type.BOOLEAN,
                    description="Search subdirectories recursively (default true)",
                ),
            },
            required=["path", "pattern"],
        ),
    ),
    types.FunctionDeclaration(
        name="file_syntax_check",
        description=(
            "Check the syntax of a Python (.py) or JSON (.json) file without executing it. "
            "Returns OK or the error with line number. "
            "Use after editing a file before restarting Cortex. "
            "Restricted to the Cortex project directory."
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "path": types.Schema(
                    type=types.Type.STRING,
                    description="Path to the .py or .json file to check",
                ),
            },
            required=["path"],
        ),
    ),
    # System-scoped
    types.FunctionDeclaration(
        name="file_read",
        description=(
            "Read a local file from the broader system (~/agents_sync/, ~/OSIT_dev/, ~/DgrZone_Nextcloud/, "
            "~/OSIT_Nextcloud/, Cortex home/). Supports offset for reading specific line ranges. "
            "For files within the Cortex project, prefer project_file_read instead. "
            "ADMIN ONLY."
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "path": types.Schema(
                    type=types.Type.STRING,
                    description="Absolute or ~/... path to the file",
                ),
                "offset": types.Schema(
                    type=types.Type.INTEGER,
                    description="Start reading from this line number (1-based)",
                ),
                "max_lines": types.Schema(
                    type=types.Type.INTEGER,
                    description="Maximum lines to return (default 500)",
                ),
            },
            required=["path"],
        ),
    ),
    types.FunctionDeclaration(
        name="file_list",
        description=(
            "List files and subdirectories from the broader system. "
            "Shows sizes and modified timestamps. "
            "Allowed: ~/agents_sync/, ~/OSIT_dev/, ~/DgrZone_Nextcloud/, ~/OSIT_Nextcloud/. "
            "ADMIN ONLY."
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "path": types.Schema(
                    type=types.Type.STRING,
                    description="Absolute or ~/... path to the directory",
                ),
            },
            required=["path"],
        ),
    ),
    types.FunctionDeclaration(
        name="file_write",
        description=(
            "Write or append content to a file. "
            "Write-allowed paths: ~/agents_sync/ and the Cortex home/ directory. "
            "Creates parent directories if needed. "
            "ADMIN ONLY. Requires user confirmation before executing."
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "path": types.Schema(
                    type=types.Type.STRING,
                    description="Absolute or ~/... path to write to",
                ),
                "content": types.Schema(
                    type=types.Type.STRING,
                    description="Content to write",
                ),
                "mode": types.Schema(
                    type=types.Type.STRING,
                    description="'overwrite' (default, replaces file) or 'append' (adds to end)",
                ),
            },
            required=["path", "content"],
        ),
    ),
    types.FunctionDeclaration(
        name="session_read",
        description=(
            "Read a full conversation session log by date (YYYY-MM-DD). "
            "Useful for continuity and recalling past decisions. "
            "If the date is not found, lists available dates. "
            "Only reads this user's own sessions."
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "date": types.Schema(
                    type=types.Type.STRING,
                    description="Date in YYYY-MM-DD format (e.g. '2026-05-08')",
                ),
            },
            required=["date"],
        ),
    ),
    types.FunctionDeclaration(
        name="session_search",
        description=(
            "Search past conversation session logs for a keyword or phrase. "
            "Returns matching excerpts with session dates, newest first. "
            "Only searches this user's own sessions."
        ),
        parameters=types.Schema(
            type=types.Type.OBJECT,
            properties={
                "query": types.Schema(
                    type=types.Type.STRING,
                    description="Keyword or phrase to search for",
                ),
                "limit": types.Schema(
                    type=types.Type.INTEGER,
                    description="Max results to return (default 5, max 20)",
                ),
            },
            required=["query"],
        ),
    ),
]