from __future__ import annotations

from dataclasses import dataclass
from datetime import datetime
import logging
import os
import sys
import time
from typing import Iterable

try:
    from rich.console import Console
    from rich.logging import RichHandler
    from rich.table import Table
    from rich.text import Text
except ImportError:  # pragma: no cover - exercised only before dependency install
    Console = None
    RichHandler = None
    Table = None
    Text = None


@dataclass(frozen=True)
class LoggingSettings:
    app_name: str
    app_env: str
    host: str
    port: int
    log_level: str
    log_verbose: bool
    database_url: str
    version: str


@dataclass(frozen=True)
class StartupStatus:
    app_name: str
    version: str
    environment: str
    host: str
    port: int
    database: str
    mode: str
    started_at: str
    local_url: str
    network_url: str


class PlainFormatter(logging.Formatter):
    default_time_format = "%Y-%m-%d %H:%M:%S"

    def format(self, record: logging.LogRecord) -> str:
        if not hasattr(record, "component"):
            record.component = record.name.rsplit(".", 1)[-1]
        return super().format(record)


def _allow_color() -> bool:
    if RichHandler is None or Console is None:
        return False
    if os.getenv("NO_COLOR"):
        return False
    if os.getenv("TERM") == "dumb":
        return False
    return hasattr(sys.stderr, "isatty") and sys.stderr.isatty()


def _allow_unicode() -> bool:
    encoding = (getattr(sys.stdout, "encoding", None) or "").lower()
    if not encoding:
        return False
    return "utf" in encoding


def _console() -> Console:
    return Console(
        stderr=True,
        soft_wrap=False,
        highlight=False,
        force_terminal=_allow_color(),
        no_color=not _allow_color(),
        emoji=False,
    )


def _rich_handler(level: str) -> RichHandler:
    return RichHandler(
        level=level,
        console=_console(),
        show_time=True,
        show_level=True,
        show_path=False,
        omit_repeated_times=False,
        markup=True,
        rich_tracebacks=True,
        tracebacks_show_locals=False,
        log_time_format="%H:%M:%S",
    )


def _plain_handler(level: str) -> logging.StreamHandler:
    handler = logging.StreamHandler()
    handler.setLevel(level)
    handler.setFormatter(
        PlainFormatter("%(asctime)s | %(levelname)-7s | %(component)-10s | %(message)s")
    )
    return handler


def _handler(level: str) -> logging.Handler:
    return _rich_handler(level) if _allow_color() else _plain_handler(level)


def configure_logging(settings: LoggingSettings) -> None:
    level = settings.log_level.upper()
    root = logging.getLogger()
    root.handlers.clear()
    root.setLevel(level)
    root.addHandler(_handler(level))

    for name in ("uvicorn", "uvicorn.error", "fastapi"):
        logger = logging.getLogger(name)
        logger.handlers.clear()
        logger.setLevel(level)
        logger.propagate = True

    access_logger = logging.getLogger("uvicorn.access")
    access_logger.handlers.clear()
    access_logger.propagate = False
    access_logger.disabled = True


def get_logger(name: str) -> logging.LoggerAdapter[logging.Logger]:
    component = name.rsplit(".", 1)[-1]
    return logging.LoggerAdapter(logging.getLogger(name), {"component": component})


def _icon(name: str) -> str:
    ascii_icons = {
        "app": "#",
        "info": "i",
        "success": "+",
        "warning": "!",
        "error": "x",
        "debug": ".",
        "section": "=",
        "url": ">",
        "shutdown": "-",
    }
    unicode_icons = {
        "app": "◆",
        "info": "ℹ",
        "success": "✓",
        "warning": "▲",
        "error": "✖",
        "debug": "•",
        "section": "─",
        "url": "↳",
        "shutdown": "◦",
    }
    icons = unicode_icons if _allow_unicode() else ascii_icons
    return icons[name]


def _style(name: str) -> str:
    return {
        "info": "bold cyan",
        "success": "bold green",
        "warning": "bold yellow",
        "error": "bold red",
        "debug": "dim",
        "section": "bold bright_blue",
        "muted": "grey62",
    }[name]


def section_heading(title: str) -> None:
    logger = get_logger("data_entry_app.section")
    if _allow_color():
        _console().rule(Text(f" {title.upper()} ", style=_style("section")))
        return
    logger.info("%s %s %s", _icon("section") * 10, title.upper(), _icon("section") * 10)


def startup_banner(status: StartupStatus) -> None:
    logger = get_logger("data_entry_app.startup")
    if _allow_color():
        console = _console()
        table = Table.grid(expand=False)
        table.add_column(style="bold white", justify="left")
        table.add_column(style="white", justify="left")
        table.add_row("Environment", status.environment)
        table.add_row("Version", status.version)
        table.add_row("Host", status.host)
        table.add_row("Port", str(status.port))
        table.add_row("Database", status.database)
        table.add_row("Mode", status.mode)
        table.add_row("Started", status.started_at)

        console.rule(Text(f" {status.app_name} ", style="bold white"))
        console.print(Text("Clean startup. Clear status. Ready.", style="italic cyan"))
        console.print(table)
        console.print()
        console.print(Text("App is running at:", style="bold white"))
        console.print(Text(f"  Local:   {status.local_url}", style="cyan"))
        console.print(Text(f"  Network: {status.network_url}", style="cyan"))
        console.print()
        return

    logger.info("%s %s", _icon("app"), "Startup banner")
    logger.info("App         : %s", status.app_name)
    logger.info("Environment : %s", status.environment)
    logger.info("Version     : %s", status.version)
    logger.info("Host        : %s", status.host)
    logger.info("Port        : %s", status.port)
    logger.info("Database    : %s", status.database)
    logger.info("Mode        : %s", status.mode)
    logger.info("Started     : %s", status.started_at)
    logger.info("Local       : %s", status.local_url)
    logger.info("Network     : %s", status.network_url)


def status_message(level: str, message: str, *args: object, logger_name: str = "data_entry_app.status") -> None:
    palette = {
        "debug": logging.DEBUG,
        "info": logging.INFO,
        "success": logging.INFO,
        "warning": logging.WARNING,
        "error": logging.ERROR,
    }
    labels = {
        "debug": f"[{_icon('debug')}]",
        "info": f"[{_icon('info')}]",
        "success": f"[{_icon('success')}]",
        "warning": f"[{_icon('warning')}]",
        "error": f"[{_icon('error')}]",
    }
    styles = {
        "debug": _style("debug"),
        "info": _style("info"),
        "success": _style("success"),
        "warning": _style("warning"),
        "error": _style("error"),
    }
    logger = get_logger(logger_name)
    rendered = message % args if args else message
    if _allow_color():
        logger.log(palette[level], f"[{styles[level]}]{labels[level]}[/] {rendered}")
    else:
        logger.log(palette[level], "%s %s", labels[level], rendered)


def success(message: str, *args: object, logger_name: str = "data_entry_app.status") -> None:
    status_message("success", message, *args, logger_name=logger_name)


def warning(message: str, *args: object, logger_name: str = "data_entry_app.status") -> None:
    status_message("warning", message, *args, logger_name=logger_name)


def info(message: str, *args: object, logger_name: str = "data_entry_app.status") -> None:
    status_message("info", message, *args, logger_name=logger_name)


def debug(message: str, *args: object, logger_name: str = "data_entry_app.status") -> None:
    status_message("debug", message, *args, logger_name=logger_name)


def fatal(message: str, *args: object, exc_info: bool = False, logger_name: str = "data_entry_app.status") -> None:
    logger = get_logger(logger_name)
    rendered = message % args if args else message
    if _allow_color():
        logger.error(f"[{_style('error')}][{_icon('error')}][/] {rendered}", exc_info=exc_info)
    else:
        logger.error("[%s] %s", _icon("error"), rendered, exc_info=exc_info)


def shutdown_summary(*, uptime_seconds: float, requests_served: int, host: str, port: int) -> None:
    section_heading("Shutdown")
    logger = get_logger("data_entry_app.shutdown")
    summary = f"Uptime {uptime_seconds:.1f}s | Requests {requests_served} | Endpoint http://{host}:{port}"
    if _allow_color():
        logger.info(f"[{_style('debug')}]{_icon('shutdown')}[/] {summary}")
    else:
        logger.info("%s %s", _icon("shutdown"), summary)


def describe_database(url: str) -> str:
    if url.startswith("sqlite"):
        return "sqlite"
    if "postgresql" in url:
        return "postgresql"
    if "mysql" in url:
        return "mysql"
    return url.split(":", 1)[0]


def sanitize_database_target(url: str) -> str:
    if url.startswith("sqlite:///"):
        return url.removeprefix("sqlite:///")
    if "@" in url:
        return url.split("@", 1)[1]
    return url


def startup_status(settings: LoggingSettings) -> StartupStatus:
    host = settings.host
    local_host = "localhost" if host in {"0.0.0.0", "::"} else host
    timestamp = datetime.now().astimezone().strftime("%Y-%m-%d %H:%M:%S %Z")
    return StartupStatus(
        app_name=settings.app_name,
        version=settings.version,
        environment=settings.app_env,
        host=settings.host,
        port=settings.port,
        database=f"{describe_database(settings.database_url)} ({sanitize_database_target(settings.database_url)})",
        mode="verbose" if settings.log_verbose else "normal",
        started_at=timestamp,
        local_url=f"http://{local_host}:{settings.port}",
        network_url=f"http://{host}:{settings.port}",
    )


def route_summary(routes: Iterable[object]) -> tuple[int, list[str]]:
    lines: list[str] = []
    count = 0
    for route in routes:
        path = getattr(route, "path", None)
        methods = getattr(route, "methods", None)
        if not path or not methods:
            continue
        filtered_methods = sorted(method for method in methods if method not in {"HEAD", "OPTIONS"})
        if not filtered_methods:
            continue
        count += 1
        lines.append(f"{','.join(filtered_methods):<7} {path}")
    return count, lines


def log_request(
    *,
    method: str,
    path: str,
    status_code: int,
    duration_ms: float,
    client: str,
    content_length: str | None,
) -> None:
    level = "info"
    if status_code >= 500:
        level = "error"
    elif status_code >= 400:
        level = "warning"
    elif path == "/health":
        level = "debug"

    message = (
        f"{method:<6} {status_code:>3} {duration_ms:>7.1f}ms "
        f"{path:<36} client={client}"
    )
    if content_length:
        message += f" bytes={content_length}"
    status_message(level, message, logger_name="data_entry_app.http")


class RequestTimer:
    def __init__(self) -> None:
        self.started = time.perf_counter()

    @property
    def elapsed_ms(self) -> float:
        return (time.perf_counter() - self.started) * 1000