106 lines
3.5 KiB
Nim
106 lines
3.5 KiB
Nim
import std/[json, nre, os, sequtils, strtabs, strutils]
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import docopt
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type
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CombinedConfig* = object
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docopt*: Table[string, Value]
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json*: JsonNode
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func keyNames(key: string): tuple[arg, env, json: string] =
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result = (
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"--" & key,
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key.replace('-', '_').toUpper,
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key.replace(re"(-\w)", proc (m: RegexMatch): string = ($m)[1..1].toUpper))
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template walkFieldDefs*(t: NimNode, body: untyped) =
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let tTypeImpl = t.getTypeImpl
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var nodeToItr: NimNode
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if tTypeImpl.typeKind == ntyObject: nodeToItr = tTypeImpl[2]
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elif tTypeImpl.typeKind == ntyTypeDesc: nodeToItr = tTypeImpl.getType[1].getType[2]
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else: error $t & " is not an object or type desc (it's a " & $tTypeImpl.typeKind & ")."
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for fieldDef {.inject.} in nodeToItr.children:
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# ignore AST nodes that are not field definitions
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if fieldDef.kind == nnkIdentDefs:
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let fieldIdent {.inject.} = fieldDef[0]
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let fieldType {.inject.} = fieldDef[1]
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body
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elif fieldDef.kind == nnkSym:
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let fieldIdent {.inject.} = fieldDef
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let fieldType {.inject.} = fieldDef.getType
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body
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# TODO: Generic config loader
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# macro loadConfig*(filePath: string, cfgType: typed, args: Table[string, docopt.Value): untyped =
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# result = newNimNode(nnkObjConstr).(cfgType)
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#
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# var idx = 0
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# cfgType.walkFieldDefs:
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# let valLookup = quote do: `getVal`(
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proc initCombinedConfig*(
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filename: string,
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docopt: Table[string, Value] = initTable[string, Value]()
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): CombinedConfig =
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result = CombinedConfig(docopt: docopt, json: parseFile(filename))
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proc findConfigFile*(name: string, otherLocations: seq[string] = @[]): string =
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let cfgLocations = @[
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$getEnv(name.strip(chars = {'.'}).toUpper()),
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$getEnv("HOME") / name ] & otherLocations
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result = cfgLocations.foldl(if fileExists(b): b else: a, "")
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if result == "" or not fileExists(result):
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raise newException(ValueError, "could not find configuration file")
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proc getVal*(cfg: CombinedConfig, key: string): string =
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let (argKey, envKey, jsonKey) = keyNames(key)
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if cfg.docopt.contains(argKey) and cfg.docopt[argKey]: return $cfg.docopt[argKey]
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elif existsEnv(envKey): return getEnv(envKey)
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elif cfg.json.hasKey(jsonKey):
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let node = cfg.json[jsonKey]
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case node.kind
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of JString: return node.getStr
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of JInt: return $node.getInt
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of JFloat: return $node.getFloat
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of JBool: return $node.getBool
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of JNull: return ""
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of JObject: return $node
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of JArray: return $node
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else: raise newException(ValueError, "cannot find a configuration value for \"" & key & "\"")
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proc getVal*(cfg: CombinedConfig, key, default: string): string =
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try: return getVal(cfg, key)
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except: return default
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proc getJson*(cfg: CombinedConfig, key: string): JsonNode =
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let (argKey, envKey, jsonKey) = keyNames(key)
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if cfg.docopt.contains(argKey) and cfg.docopt[argKey]: return parseJson($cfg.docopt[argKey])
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elif existsEnv(envKey): return parseJson(getEnv(envKey))
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elif cfg.json.hasKey(jsonKey): return cfg.json[jsonKey]
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else: raise newException(ValueError, "cannot find a configuration value for \"" & key & "\"")
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proc getJson*(cfg: CombinedConfig, key: string, default: JsonNode): JsonNode =
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try: return getJson(cfg, key)
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except: return default
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proc hasKey*(cfg: CombinedConfig, key: string): bool =
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let (argKey, envKey, jsonKey) = keyNames(key)
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return
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(cfg.docopt.contains(argKey) and cfg.docopt[argKey]) or
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existsEnv(envKey) or
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cfg.json.hasKey(jsonKey)
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proc loadEnv*(): StringTableRef =
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result = newStringTable()
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for k, v in envPairs():
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result[k] = v
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