1 files changed, 123 insertions, 0 deletions
diff --git a/src/wrapper/curl.nim b/src/wrapper/curl.nim
new file mode 100644
index 0000000..5f3e814
--- /dev/null
+++ b/src/wrapper/curl.nim
@@ -0,0 +1,123 @@
+import
+  strutils,
+  "../utils"
+
+type
+  CurlHandle* = object
+
+  CurlInstance* = object
+    handle: ptr CurlHandle
+    data: seq[char]
+
+  CurlOption {.pure, size: sizeof(cint).} = enum
+    followLocation = 52,
+    noSignal = 99,
+    timeoutMs = 155,
+    connectTimeoutMs = 156,
+    writeData = 10001,
+    url = 10002,
+    writeFunction = 20011
+
+  CurlError* = object of Exception
+
+{.passL: "-lcurl".}
+
+proc initCurlGlobal*(flags: clong): cint
+  {.cdecl, importc: "curl_global_init".}
+
+proc cleanupCurlGlobal*: void
+  {.cdecl, importc: "curl_global_cleanup".}
+
+proc newCurlHandle*: ptr CurlHandle
+  {.cdecl, importc: "curl_easy_init".}
+
+proc cleanup*(handle: ptr CurlHandle)
+  {.cdecl, importc: "curl_easy_cleanup".}
+
+proc errorCurl*(error: cint): cstring
+  {.cdecl, importc: "curl_easy_strerror".}
+
+proc setOption*(handle: ptr CurlHandle, option: CurlOption): cint
+  {.cdecl, importc: "curl_easy_setopt", varargs.}
+
+proc perform*(handle: ptr CurlHandle): cint
+  {.cdecl, importc: "curl_easy_perform".}
+
+proc escape*(handle: ptr CurlHandle, input: cstring, length: cint): cstring
+  {.cdecl, importc: "curl_easy_escape".}
+
+proc freeCurl*(data: pointer)
+  {.cdecl, importc: "curl_free".}
+
+proc escape*(instance: ref CurlInstance, s: string): string =
+  let esc = instance.handle.escape(s, 0)
+  if esc != nil:
+    let nesc = $esc
+    freeCurl(esc)
+    nesc
+  else:
+    ""
+
+proc curlWriteMemory(mem: array[csize.high, char], size: csize, nmemb: csize,
+  userdata: ref CurlInstance): csize {.cdecl.} =
+  let total = size * nmemb
+  if total > 0:
+    userData.data &= mem[0 .. total - 1]
+  total
+
+var refCount = 0
+
+template withCurlGlobal*(body: untyped): untyped =
+  block:
+    if refCount == 0:
+      if initCurlGlobal(0) != 0:
+        raise commandError(tr"failed to initialize curl library")
+    refCount += 1
+    try:
+      body
+    finally:
+      refCount -= 1
+      if refCount == 0:
+        cleanupCurlGlobal()
+
+template withCurl*(instance: untyped, body: untyped): untyped =
+  block:
+    let handle = newCurlHandle()
+    if handle == nil:
+      raise commandError(tr"failed to initialize curl handle")
+
+    var instance: ref CurlInstance
+    new(instance)
+    instance.handle = handle
+    instance.data = newSeq[char]()
+
+    proc raiseError(code: cint) =
+      if code != 0:
+        let msg = code.errorCurl
+        if msg != nil:
+          raise newException(CurlError, tr"failed to perform request" & (": $#" % [$msg]))
+        else:
+          raise newException(CurlError, tr"failed to perform request")
+
+    proc performInternal(url: string): seq[char] =
+      raiseError(handle.setOption(CurlOption.followLocation, (clong) 1))
+      raiseError(handle.setOption(CurlOption.noSignal, (clong) 1))
+      raiseError(handle.setOption(CurlOption.timeoutMs, (clong) 15000))
+      raiseError(handle.setOption(CurlOption.connectTimeoutMs, (clong) 15000))
+      raiseError(handle.setOption(CurlOption.url, url))
+      raiseError(handle.setOption(CurlOption.writeFunction, cast[pointer](curlWriteMemory)))
+      raiseError(handle.setOption(CurlOption.writeData, instance))
+      raiseError(handle.perform())
+      instance.data
+
+    proc performString(url: string): string =
+      let data = performInternal(url)
+      var str = newStringOfCap(data.len)
+      for c in data:
+        str.add(c)
+      str
+
+    try:
+      body
+    finally:
+      handle.cleanup()