import json
import pathlib
from typing import Any, Dict, List, Optional

from .constants import FIRSTBOOT_DIR, FIRSTBOOT_DONE, FIRSTBOOT_ERROR, FIRSTBOOT_LOG, FIRSTBOOT_STATE, WEB_ROOT
from .helpers import ensure_dir, sha256_file

DEFAULT_STEPS = [
    "Preparing system",
    "Generating security keys",
    "Securing the dashboard",
    "Updating software (this can take a while)",
    "Final checks",
    "Starting Pi-Kit",
]


def _tail_text(path: pathlib.Path, max_lines: int = 200) -> str:
    if not path.exists():
        return ""
    try:
        text = path.read_text(errors="ignore")
    except Exception:
        return ""
    lines = text.splitlines()
    if len(lines) > max_lines:
        lines = lines[-max_lines:]
    return "\n".join(lines)


def _normalize_steps(raw_steps: Optional[List[Dict[str, Any]]], state: str) -> List[Dict[str, Any]]:
    steps: List[Dict[str, Any]] = []
    if raw_steps:
        for entry in raw_steps:
            label = (entry or {}).get("label") or (entry or {}).get("name")
            if not label:
                continue
            status = (entry or {}).get("status") or "pending"
            steps.append({"label": str(label), "status": str(status)})

    if not steps:
        steps = [{"label": label, "status": "pending"} for label in DEFAULT_STEPS]

    if state == "done":
        for step in steps:
            step["status"] = "done"
    return steps


def _current_step(steps: List[Dict[str, Any]]) -> Optional[str]:
    for step in steps:
        if step.get("status") in ("current", "running", "error"):
            return step.get("label")
    return None


def _load_state_file() -> Dict[str, Any]:
    if FIRSTBOOT_STATE.exists():
        try:
            return json.loads(FIRSTBOOT_STATE.read_text())
        except Exception:
            return {}
    return {}


def read_firstboot_status() -> Dict[str, Any]:
    ensure_dir(FIRSTBOOT_DIR)
    state_file = _load_state_file()

    if FIRSTBOOT_ERROR.exists():
        state = "error"
    elif FIRSTBOOT_DONE.exists():
        state = "done"
    else:
        state = state_file.get("state") or "running"
        if state not in ("running", "done", "error"):
            state = "running"

    steps = _normalize_steps(state_file.get("steps"), state)
    current_step = state_file.get("current_step") or _current_step(steps)

    ca_path = WEB_ROOT / "assets" / "pikit-ca.crt"
    ca_hash = sha256_file(ca_path) if ca_path.exists() else None

    return {
        "state": state,
        "steps": steps,
        "current_step": current_step,
        "log_tail": _tail_text(FIRSTBOOT_LOG, 200),
        "error_present": FIRSTBOOT_ERROR.exists(),
        "error_path": "/api/firstboot/error",
        "ca_hash": ca_hash,
        "ca_url": "/assets/pikit-ca.crt",
    }


def read_firstboot_error(max_lines: int = 200) -> Dict[str, Any]:
    if not FIRSTBOOT_ERROR.exists():
        return {"present": False, "text": ""}
    return {"present": True, "text": _tail_text(FIRSTBOOT_ERROR, max_lines)}