typstgen/src/typstgen.nim

import std/[os, sequtils, streams, strutils,  tables]
import yaml, hwylterm

type
  Component = Table[string, string]
  TypstTemplate = object
    keys: seq[string]
    src: string
  Config = object
    components {.defaultVal: @[]}: seq[Component]
    templates {.defaultVal: initTable[string, TypstTemplate]()}: Table[string, TypstTemplate]

func `%`(t: TypstTemplate, a: openArray[string]): string =
  t.src % a

proc checkTemplates(templates: Table[string, TypstTemplate]) =
  ## quit if any templates have the same keys
  var keyTable: Table[string, seq[string]]

  for name, templ in templates.pairs():
    let k = templ.keys.join(";")
    if k in keyTable:
      keyTable[k].add name
    else:
      keyTable[k] = @[name]

  for keys, names in keyTable.pairs():
    if names.len > 1:
      quit("non-unique key combos in templates: " & names.join(","))


proc addDefaultTemplates(c: var Config) =
  # TODO: more default templates?
  if "raw" notin c.templates:
    c.templates["raw"] = TypstTemplate(keys: @["raw"], src: "$raw")

  if "image" notin c.templates:
    c.templates["image"] = TypstTemplate(keys: @["image"], src: """
#figure(
  image("$image"),
  caption: [$image]
)
"""
      )

  if "figure" notin c.templates:
    c.templates["figure"] = TypstTemplate(keys: @["image", "caption"], src: """
#align(center)[
  #figure(
    image("$image"),
    caption: [
      $image
    ]
  )
  $caption
]
"""
      )


proc loadConfig(configPath: string): Config =

  var s = newFileStream(configPath)
  load(s, result)
  close s

  addDefaultTemplates result
  checkTemplates result.templates

proc getTemplate(c: Config, component: Component): TypstTemplate =
  let k = component.keys().toSeq()
  for _, templ in c.templates.pairs():
    if templ.keys == k:
      return templ

  quit($bb("[red]error[/] failed to find template for component:\n") & $component)

func toFmtArgs(comp: Component): seq[string] =
    for k, v in comp.pairs: result.add k; result.add v

proc applyTemplate(c: Config, component: Component): string =
  let templ = c.getTemplate(component)
  result = templ % component.toFmtArgs()

proc typstGen(c: Config): string =
  for component in c.components:
    result &= c.applyTemplate(component)

when isMainModule:
  import hwylterm/[cli, parseopt3]
  proc writeHelp() =
    echo newHwylCli(
      "[bold]typstgen[/] [[[faint]-h[/]]",
      """
  typstgen --config typstgen.yml""",
      [
        ("h", "help", "show this help"),
        ("c","config", "path to config file"),
        ("","check", "load config and exit"),
      ]
    )
  var
    p = initOptParser(longNoVal= @["check"])
    configPath = "typstgen.yml"
    check: bool
  for kind, key, val in p.getopt():
    case kind
    of cmdError: quit($bb"[red]cli error[/]: " & p.message)
    of cmdEnd: assert false
    of cmdArgument: quit($bb"[red] unexpected argument[/]: " & key)
    of cmdShortOption, cmdLongOption:
      case key
      of "help", "h":
        writeHelp(); quit 0
      of "config", "c":
        configPath = val
      of "check":
        check = true

  if not fileExists(configPath):
    quit($bbfmt("file: [b]{configPath}[/] does not exist"))

  let config = loadConfig(configPath)
  if check: quit 0
  echo typstGen(config)