"""Managed Claude Code task command, environment, and stdout parsing."""

import json
from collections.abc import Iterable, Mapping
from dataclasses import dataclass, field
from typing import Any

from loguru import logger

from free_claude_code.cli.claude_env import (
    CLAUDE_BINARY_NAME,
    build_claude_proxy_env,
)

MANAGED_CLAUDE_MODEL_TIER = "fable"


@dataclass(frozen=True, slots=True)
class ManagedClaudeTaskRequest:
    """One prompt execution request for a managed Claude Code subprocess."""

    prompt: str
    session_id: str | None = None
    fork_session: bool = False


@dataclass(frozen=True, slots=True)
class ManagedClaudeInvocation:
    """Concrete subprocess invocation assembled for a managed Claude task."""

    argv: tuple[str, ...]
    env: dict[str, str]
    cwd: str
    trace_metadata: dict[str, Any] = field(default_factory=dict)


@dataclass(frozen=True, slots=True)
class ManagedClaudeConfig:
    """Configuration for a managed Claude Code subprocess."""

    workspace_path: str
    proxy_root_url: str
    allowed_dirs: list[str] = field(default_factory=list)
    claude_bin: str = CLAUDE_BINARY_NAME
    auth_token: str = ""


@dataclass(slots=True)
class ManagedClaudeParseState:
    """Mutable stdout parser state for one managed Claude Code task run."""

    log_raw_cli_diagnostics: bool = False
    session_id_extracted: bool = False


def build_managed_claude_invocation(
    *,
    config: ManagedClaudeConfig,
    request: ManagedClaudeTaskRequest,
    base_env: Mapping[str, str],
) -> ManagedClaudeInvocation:
    """Build a Claude Code stream-json subprocess invocation."""

    cmd = build_managed_claude_command(
        claude_bin=config.claude_bin,
        prompt=request.prompt,
        session_id=request.session_id,
        fork_session=request.fork_session,
        allowed_dirs=config.allowed_dirs,
    )
    resume_session_id = (
        request.session_id
        if request.session_id and not request.session_id.startswith("pending_")
        else None
    )
    return ManagedClaudeInvocation(
        argv=tuple(cmd),
        env=build_managed_claude_env(
            proxy_root_url=config.proxy_root_url,
            auth_token=config.auth_token,
            base_env=base_env,
        ),
        cwd=config.workspace_path,
        trace_metadata={
            "client_cli_id": "claude",
            "resume_session_id": resume_session_id,
            "fork_session": request.fork_session,
            "prompt": request.prompt,
            "cwd": config.workspace_path,
            "claude_binary": config.claude_bin,
            "managed_model_tier": MANAGED_CLAUDE_MODEL_TIER,
            "cli_argv": cmd,
        },
    )


def build_managed_claude_env(
    *,
    proxy_root_url: str,
    auth_token: str,
    base_env: Mapping[str, str],
) -> dict[str, str]:
    """Return a Claude Code task environment that targets the local proxy."""

    env = build_claude_proxy_env(
        proxy_root_url=proxy_root_url,
        auth_token=auth_token,
        base_env=base_env,
    )
    env["TERM"] = "dumb"
    env["PYTHONIOENCODING"] = "utf-8"
    return env


def build_managed_claude_command(
    *,
    claude_bin: str,
    prompt: str,
    session_id: str | None,
    fork_session: bool,
    allowed_dirs: list[str],
) -> list[str]:
    """Return the Claude Code stream-json command for a managed task."""

    if session_id and not session_id.startswith("pending_"):
        cmd = [
            claude_bin,
            "--resume",
            session_id,
        ]
        if fork_session:
            cmd.append("--fork-session")
        cmd += [
            "--model",
            MANAGED_CLAUDE_MODEL_TIER,
            "-p",
            prompt,
            "--output-format",
            "stream-json",
            "--dangerously-skip-permissions",
            "--verbose",
        ]
    else:
        cmd = [
            claude_bin,
            "--model",
            MANAGED_CLAUDE_MODEL_TIER,
            "-p",
            prompt,
            "--output-format",
            "stream-json",
            "--dangerously-skip-permissions",
            "--verbose",
        ]

    for directory in allowed_dirs:
        cmd.extend(["--add-dir", directory])

    return cmd


def parse_managed_claude_stdout_line(
    line: str, state: ManagedClaudeParseState
) -> Iterable[Any]:
    """Parse one Claude Code stream-json stdout line."""

    try:
        event = json.loads(line)
    except json.JSONDecodeError:
        if state.log_raw_cli_diagnostics:
            logger.debug("Non-JSON output: {}", line)
        else:
            logger.debug("Non-JSON CLI line: char_len={}", len(line))
        yield {"type": "raw", "content": line}
        return

    if not state.session_id_extracted:
        extracted_id = extract_managed_claude_session_id(event)
        if extracted_id:
            state.session_id_extracted = True
            logger.info("Extracted session ID: {}", extracted_id)
            yield {"type": "session_info", "session_id": extracted_id}

    yield event


def extract_managed_claude_session_id(event: Any) -> str | None:
    """Extract a Claude Code session ID from supported stream-json event shapes."""

    if not isinstance(event, dict):
        return None

    if session_id := _string_value(event.get("session_id")):
        return session_id
    if session_id := _string_value(event.get("sessionId")):
        return session_id

    for key in ("init", "system", "result", "metadata"):
        nested = event.get(key)
        if not isinstance(nested, dict):
            continue
        if session_id := _string_value(nested.get("session_id")):
            return session_id
        if session_id := _string_value(nested.get("sessionId")):
            return session_id

    conversation = event.get("conversation")
    if isinstance(conversation, dict):
        return _string_value(conversation.get("id"))

    return None


def _string_value(value: Any) -> str | None:
    return value if isinstance(value, str) else None