"""Shared paths, constants and small helpers for the dyson100 study."""
import io
import os
import time
import uuid
import urllib.parse
import urllib.request

import numpy as np

STUDY = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
RAW = os.environ.get("DYSON100_RAW", "fermi_raw/dyson100")
DATA = os.path.join(STUDY, "data")
FIG = os.path.join(STUDY, "figures")
for _d in (RAW, DATA, FIG):
    os.makedirs(_d, exist_ok=True)

VIZIER_TAP = "https://tapvizier.cds.unistra.fr/TAPVizieR/tap/sync"
GAIA_TAP = "https://gea.esac.esa.int/tap-server/tap/sync"
IRSA_TAP = "https://irsa.ipac.caltech.edu/TAP/sync"
SIMBAD_TAP = "https://simbad.cds.unistra.fr/simbad/sim-tap/sync"

# ---------------------------------------------------------------- photometry
# Zero-magnitude flux densities (Jy).  WISE: Jarrett et al. 2011 / Explanatory
# Supplement (W4 uses the standard 8.363 Jy; no red-source correction applied
# to data, the same convention is used for injected models).  2MASS: Cohen+03.
F0 = dict(J=1594.0, H=1024.0, Ks=666.7, W1=309.540, W2=171.787, W3=31.674, W4=8.363)
# Isophotal wavelengths in micron
LAM = dict(J=1.235, H=1.662, Ks=2.159, W1=3.3526, W2=4.6028, W3=11.5608, W4=22.0883)
# AllWISE instrumental zero points: mag = ZP - 2.5 log10(flux_DN)
ZP_DN = dict(W1=20.5, W2=19.5, W3=18.0, W4=13.0)

H_PLANCK = 6.62607015e-34
C_LIGHT = 2.99792458e8
K_B = 1.380649e-23
SIGMA_SB = 5.670374419e-8
LSUN = 3.828e26
PC = 3.0856775814913673e16
MBOL_SUN = 4.74

T_GRID = [100, 150, 200, 300, 400, 600]
F_GRID = [1e-4, 2e-4, 5e-4, 1e-3, 2e-3, 5e-3, 1e-2, 2e-2, 3e-2, 5e-2, 7e-2, 0.1, 0.2, 0.3, 0.5, 0.7, 0.9]


def mag2jy(mag, band):
    return F0[band] * 10.0 ** (-0.4 * np.asarray(mag, dtype=float))


def jy2mag(f, band):
    f = np.asarray(f, dtype=float)
    with np.errstate(invalid="ignore", divide="ignore"):
        return -2.5 * np.log10(f / F0[band])


def planck_nu(lam_um, T):
    """B_nu in W m^-2 Hz^-1 sr^-1."""
    nu = C_LIGHT / (np.asarray(lam_um, dtype=float) * 1e-6)
    x = H_PLANCK * nu / (K_B * T)
    return 2 * H_PLANCK * nu ** 3 / C_LIGHT ** 2 / np.expm1(x)


def http_get(url, params=None, timeout=600, retries=4, post=True):
    data = urllib.parse.urlencode(params).encode() if params else None
    last = None
    for k in range(retries):
        try:
            if post or data is None:
                req = urllib.request.Request(url, data=data)
            else:
                req = urllib.request.Request(url + "?" + data.decode())
            with urllib.request.urlopen(req, timeout=timeout) as r:
                return r.read()
        except Exception as e:  # noqa
            last = e
            time.sleep(5 * (k + 1))
    raise RuntimeError(f"GET failed {url}: {last}")


def tap_sync(url, query, fmt="csv", timeout=900, retries=4):
    params = {"REQUEST": "doQuery", "LANG": "ADQL", "FORMAT": fmt, "QUERY": query}
    return http_get(url, params, timeout=timeout, retries=retries).decode("utf-8", "replace")


def tap_upload(url, query, table, name="mytable", fmt="csv", timeout=900, retries=4):
    """TAP sync query with an uploaded astropy Table (multipart POST, stdlib only)."""
    buf = io.BytesIO()
    table.write(buf, format="votable")
    payload = buf.getvalue()
    b = "----" + uuid.uuid4().hex

    def part(k, v):
        return f'--{b}\r\nContent-Disposition: form-data; name="{k}"\r\n\r\n{v}\r\n'.encode()

    body = b"".join([part("REQUEST", "doQuery"), part("LANG", "ADQL"), part("QUERY", query),
                     part("FORMAT", fmt), part("UPLOAD", f"{name},param:table")])
    body += (f'--{b}\r\nContent-Disposition: form-data; name="table"; filename="t.xml"\r\n'
             f"Content-Type: application/x-votable+xml\r\n\r\n").encode() + payload + f"\r\n--{b}--\r\n".encode()
    last = None
    for k in range(retries):
        try:
            req = urllib.request.Request(url, data=body,
                                         headers={"Content-Type": "multipart/form-data; boundary=" + b})
            with urllib.request.urlopen(req, timeout=timeout) as r:
                return r.read().decode("utf-8", "replace")
        except Exception as e:  # noqa
            last = e
            time.sleep(10 * (k + 1))
    raise RuntimeError(f"TAP upload failed {url}: {last}")


XMATCH_URL = "https://cdsxmatch.u-strasbg.fr/xmatch/api/v1/sync"


def cds_xmatch(csv_text, cat2, radius_arcsec, ra="ra", dec="dec", timeout=600, retries=4):
    """CDS XMatch of an uploaded CSV table against a VizieR table or 'simbad' (stdlib only)."""
    b = "----" + uuid.uuid4().hex
    fields = dict(request="xmatch", distMaxArcsec=str(radius_arcsec), RESPONSEFORMAT="csv",
                  colRA1=ra, colDec1=dec, cat2=cat2)
    body = b"".join(f'--{b}\r\nContent-Disposition: form-data; name="{k}"\r\n\r\n{v}\r\n'.encode()
                    for k, v in fields.items())
    body += (f'--{b}\r\nContent-Disposition: form-data; name="cat1"; filename="t.csv"\r\n'
             f"Content-Type: text/csv\r\n\r\n").encode() + csv_text.encode() + f"\r\n--{b}--\r\n".encode()
    last = None
    for k in range(retries):
        try:
            req = urllib.request.Request(XMATCH_URL, data=body,
                                         headers={"Content-Type": "multipart/form-data; boundary=" + b})
            with urllib.request.urlopen(req, timeout=timeout) as r:
                return r.read().decode("utf-8", "replace")
        except Exception as e:  # noqa
            last = e
            time.sleep(5 * (k + 1))
    raise RuntimeError(f"XMatch failed for {cat2}: {last}")