import std / [strutils, strformat, httpclient, asyncdispatch, sequtils, parseutils, os, json, tables, uri]

const basePath = "https://ssd.jpl.nasa.gov/api/horizons.api?"

const outPath = currentSourcePath().parentDir.parentDir / "resources/"

export tables, json

when not defined(ssl):

{.error: "This module must be compiled with `-d:ssl`.".}

CommonOptionsKind* = enum

coFormat = "format" ## 'json', 'text'

coCommand = "COMMAND" ## defines the target body! '10' = Sun, 'MB' to get a list of available targets

coObjData = "OBJ_DATA" ## 'YES', 'NO'

coMakeEphem = "MAKE_EPHEM" ## 'YES', 'NO'

coEphemType = "EPHEM_TYPE" ## 'OBSERVER', 'VECTORS', 'ELEMENTS', 'SPK', 'APPROACH'

coEmailAddr = "EMAIL_ADDR"

## Available for 'O' = 'OBSERVER', 'V' = 'VECTOR', 'E' = 'ELEMENTS'

EphemerisOptionsKind* = enum ## O V E

eoCenter = "CENTER" ## x x x 'coord@399' = coordinate from `SiteCoord' on earth (399)

eoRefPlane = "REF_PLANE" ## x x

eoCoordType = "COORD_TYPE" ## x x x 'GEODETIC', 'CYLINDRICAL'

eoSiteCoord = "SITE_COORD" ## x x x if GEODETIC: 'E-long, lat, h': e.g. Geneva: '+6.06670,+46.23330,0'

eoStartTime = "START_TIME" ## x x x Date as 'YYYY-MM-dd'

eoStopTime = "STOP_TIME" ## x x x

eoStepSize = "STEP_SIZE" ## x x x '60 min', '1 HOURS', ...

eoTList = "TLIST" ## x x x

eoTListType = "TLIST_TYPE" ## x x x

eoQuantities = "QUANTITIES" ## x !!! These are the data fields you want to get !!!

eoRefSystem = "REF_SYSTEM" ## x x x

eoOutUnits = "OUT_UNITS " ## x x 'KM-S', 'AU-D', 'KM-D' (length & time, D = days)

eoVecTable = "VEC_TABLE " ## x

eoVecCorr = "VEC_CORR " ## x

eoCalFormat = "CAL_FORMAT" ## x

eoCalType = "CAL_TYPE" ## x x x

eoAngFormat = "ANG_FORMAT" ## x

eoApparent = "APPARENT" ## x

eoTimeDigits = "TIME_DIGITS" ## x x x

eoTimeZone = "TIME_ZONE" ## x

eoRangeUnits = "RANGE_UNITS" ## x 'AU', 'KM'

eoSuppressRangeRate = "SUPPRESS_RANGE_RATE" ## x

eoElevCut = "ELEV_CUT" ## x

eoSkipDayLT = "SKIP_DAYLT" ## x

eoSolarELong = "SOLAR_ELONG" ## x

eoAirmass = "AIRMASS" ## x

eoLHACutoff = "LHA_CUTOFF" ## x

eoAngRateCutoff = "ANG_RATE_CUTOFF" ## x

eoExtraPrec = "EXTRA_PREC" ## x

eoCSVFormat = "CSV_FORMAT" ## x x x

eoVecLabels = "VEC_LABELS" ## x

eoVecDeltaT = "VEC_DELTA_T" ## x

eoELMLabels = "ELM_LABELS " ## x

eoTPType = "TP_TYPE" ## x

eoRTSOnly = "R_T_S_ONLY" ## x

Quantities* = set[1 .. 48]

## 1. Astrometric RA & DEC

## * 2. Apparent RA & DEC

## 3. Rates; RA & DEC

## ,* 4. Apparent AZ & EL

## 5. Rates; AZ & EL

## 6. Satellite X & Y, position angle

## 7. Local apparent sidereal time

## 8. Airmass and Visual Magnitude Extinction

## 9. Visual magnitude & surface Brightness

## 10. Illuminated fraction

## 11. Defect of illumination

## 12. Satellite angle of separation/visibility code

## 13. Target angular diameter

## 14. Observer sub-longitude & sub-latitude

## 15. Sun sub-longitude & sub-latitude

## 16. Sub-Sun position angle & distance from disc center

## 17. North pole position angle & sistance from disc center

## 18. Heliocentric ecliptic longitude & latitude

## 19. Heliocentric range & range-rate

## 20. Observer range & range-rate

## 21. One-way down-leg light-time

## 22. Speed of target with respect to Sun & observer

## 23. Sun-Observer-Targ ELONGATION angle

## 24. Sun-Target-Observer ~PHASE angle

## 25. Target-Observer-Moon/Illumination%

## 26. Observer-Primary-Target angle

## 27. Position Angles; radius & -velocity

## 28. Orbit plane angle

## 29. Constellation Name

## 30. Delta-T (TDB - UT)

##,* 31. Observer-centered Earth ecliptic longitude & latitude

## 32. North pole RA & DEC

## 33. Galactic longitude and latitude

## 34. Local apparent SOLAR time

## 35. Earth->Site light-time

## > 36. RA & DEC uncertainty

## > 37. Plane-of-sky (POS) error ellipse

## > 38. Plane-of-sky (POS) uncertainty (RSS)

## > 39. Range & range-rate sigma

## > 40. Doppler/delay sigmas

## 41. True anomaly angle

##,* 42. Local apparent hour angle

## 43. PHASE angle & bisector

## 44. Apparent target-centered longitude of Sun (L_s)

##,* 45. Inertial frame apparent RA & DEC

## 46. Rates: Inertial RA & DEC

##,* 47. Sky motion: angular rate & angles

## 48. Lunar sky brightness & target visual SNR

CommonOptions* = Table[CommonOptionsKind, string]

EphemerisOptions* = Table[EphemerisOptionsKind, string]

HorizonsResponse* = object

header*: string

footer*: string

csvData*: string # <- the data field can be parsed using `parseCsvString` from `datamancer`

HorizonsRequest* = object

commonOpt*: CommonOptions

ephemerisOpt*: EphemerisOptions

quantities*: Quantities

proc serialize*[T: CommonOptions | EphemerisOptions](opts: T): string =

# turn into seq[(string, string)] and encase values in `'`

let opts = toSeq(opts.pairs).mapIt(($it[0], &"'{it[1]}'"))

result = opts.encodeQuery()

proc serialize*(q: Quantities): string =

result = "QUANTITIES='"

var i = 0

for x in q:

result.add &"{x}"

if i < q.card - 1:

result.add ","

inc i

result.add "'"

proc request*(cOpt: CommonOptions, eOpt: EphemerisOptions, q: Quantities): Future[string] {.async.} =

var req = basePath

req.add serialize(cOpt) & "&"

req.add serialize(eOpt) & "&"

req.add serialize(q)

echo "Performing request to: ", req

var client = newAsyncHttpClient()

return await client.getContent(req)

proc initHorizonsRequest*(cOpt: CommonOptions, eOpt: EphemerisOptions, q: Quantities): HorizonsRequest =

result = HorizonsRequest(commonOpt: cOpt, ephemerisOpt: eOpt, quantities: q)

proc parseHorizonsResponse*(response: string): HorizonsResponse =

## Parses the given string of the Horizons response and returns it as

## an object with header, footer and data body separated.

let res = response.parseJson["result"].getStr #.multireplace((r"\n", "FOO"))

const Start = "$$SOE"

const End = "$$EOE"

const DataHeader = "Table format"

# let's keep the parsing simple

let dataStartIdx = res.find(Start) # indicates start of data

let dataEndIdx = res.find(End)

if dataStartIdx < 0:

echo "ERROR:\n\n"

echo res

let header = res[0 ..< dataStartIdx]

let dataHeaderTab = header.find(DataHeader)

const DataHeaderStart = "*\n" ## NOTE: after `Table format`!

const DataHeaderStop = ",\n" ## NOTE: after `DataHeaderStart`!

let dataHeaderStart = header.find(DataHeaderStart, start = dataHeaderTab)

let dataHeaderStop = header.find(DataHeaderStop, start = dataHeaderStart)

let dataHeader = header[dataHeaderStart + DataHeaderStart.len .. dataHeaderStop].strip

let data = res[dataStartIdx + Start.len ..< dataEndIdx].strip

result = HorizonsResponse(header: header.strip,

footer: res[dataEndIdx + End.len .. ^1].strip,

csvData: dataHeader & "\n" & data)

proc getResponses*(reqs: seq[HorizonsRequest]): seq[HorizonsResponse] =

var futs = newSeq[Future[string]](reqs.len)

for i, r in reqs:

futs[i] = request(r.commonOpt, r.ephemerisOpt, r.quantities)

while futs.anyIt(not it.finished()):

poll()

result = newSeq[HorizonsResponse](reqs.len)

for i, f in futs:

result[i] = parseHorizonsResponse(waitFor(f))

proc getResponsesSync*(reqs: seq[HorizonsRequest]): seq[HorizonsResponse] =

## Non-async version of `getResponses`. I think the server does not like the async version

var res = newSeq[string](reqs.len)

for i, r in reqs:

res[i] = waitFor request(r.commonOpt, r.ephemerisOpt, r.quantities)

result = newSeq[HorizonsResponse](res.len)

for i, r in res:

result[i] = parseHorizonsResponse(r)

when isMainModule:

# let's try a simple request

let comOpt = { #coFormat : "text",

coMakeEphem : "YES",

coCommand : "10",

coEphemType : "OBSERVER" }.toTable

let ephOpt = { eoCenter : "coord@399",

eoStartTime : "2017-01-01",

eoStopTime : "2017-12-31",

eoStepSize : "1 DAYS",

eoCoordType : "GEODETIC",

eoSiteCoord : "+6.06670,+46.23330,0",

eoCSVFormat : "YES" }.toTable

var q: Quantities

q.incl 20 ## Observer range!

let req = initHorizonsRequest(comOpt, ephOpt, q)

let res = getResponses(@[req])

echo res

import datamancer

let df = parseCsvString(res[0].csvData)

echo df

when false:

let fut = request(comOpt, ephOpt, q)

## If multiple we would `poll`!

let res = fut.waitFor()

echo res.parseJson.pretty()