# Make Site
# author: Jonathan Bernard <jonathan@jdbernard.com>
#
# Stupid-simple static site generator. Operates on the current working
# directory. Outputs rendered HTML to a directory named 'rendered'. Reads in an
# HTML template from a file 'template.html'. Walks the current working directory
# looking for files with the '.rst' extension, splits out optional front-matter
# (JSON), compiles the rest into HTML fragments, stuffs the fragments into the
# template and write an HTML file at the same relative path in the 'rendered'
# directory with the same filename (extension changed to .html).

import json, nre, os, osproc
from strutils import endsWith, rfind

# Read in the template
let htmlTemplate = readFile("template.html")
let contentKey = re"<%CONTENT%>"
let mdExtRe = re"md$"
let tempFile = "temp.make_site.md"

# Make our output directory if necessary.
if not dirExists("rendered"): createDir("rendered")

# Walk the directory looking for .md files.
for file in walkDirRec("."):
  if not file.endsWith(".md"): continue

  echo "> Rendering " & file
  var renderedTemplate = htmlTemplate
  var mdDoc: string
  let outputFile = "rendered/" & file.replace(mdExtRe, "html")
  let outputDir = "rendered/" & file[0..file.rfind('/')]

  if not existsDir(outputDir): createDir(outputDir)

  # Split out front-matter
  let docSplit = file.readFile.split(re"\+\+\+", 2)

  # Parse the front-matter (if there is any)
  if docSplit.len > 1:
    let metadata = json.parseJson(docSplit[0])
    mdDoc = docSplit[1]
    for key, value in metadata:
      let replKey = re("<%" & key & "%>")
      renderedTemplate = htmlTemplate.replace(replKey, value.getStr)
  else: mdDoc = docSplit[0]

  # Compile the file into an HTML fragment
  writeFile(tempFile, mdDoc)
  let htmlDoc = execProcess("markdown " & tempFile)
  renderedTemplate = renderedTemplate.replace(contentKey, htmlDoc)

  writeFile(outputFile, renderedTemplate)

removeFile(tempFile)