/**
@file esbuild plugin for Civet language

Simple zero config example

@example
```javascript
import esbuild from 'esbuild'
import civetPlugin from '@danielx/civet/esbuild-plugin'

esbuild.build({
  ...,
  plugins: [
    civetPlugin
  ]
}).catch(() => process.exit(1))
```

Chain civet output into another esbuild plugin, solid for example

@example
```javascript
import esbuild from 'esbuild'
const { solidPlugin } = require('esbuild-plugin-solid');
import civetPlugin from '@danielx/civet/esbuild-plugin'

esbuild.build({
  ...,
  plugins: [
    civetPlugin(
      next: solidPlugin()
    )
  ]
}).catch(() => process.exit(1))
```
*/

import type { Plugin, OnLoadArgs, OnLoadResult } from 'esbuild'

interface Options {
  filter?: RegExp
  inlineMap?: boolean
  js?: boolean
  next?: Plugin
}

{ readFile, writeFile, mkdtemp, rmdir } from 'fs/promises'
path from 'path'
{ compile } from "./main.civet"

// NOTE: this function is named civet so esbuild gets "civet" as the name of the plugin
civet := (options: Options = {}): Plugin ->
  {
    filter=/\.civet$/
    inlineMap=true
    js=true
    next
  } := options

  let nextTransform: (args: OnLoadArgs) => OnLoadResult | Promise<OnLoadResult | null | undefined> | null | undefined
  let tmpPath: null | string

  if next
    next.setup {
      onEnd();
      onStart();
      resolve();
      onResolve();
      initialOptions();
      esbuild();
      onLoad(_, handler)
        nextTransform = handler
    }

  return {
    name: "civet"

    setup(build)

      build.onStart ->
        if next
          { tmpdir } := require 'os'
          tmpPath = await mkdtemp path.join tmpdir(), "civet-"
        return

      build.onEnd ->
        if tmpPath
          await rmdir tmpPath, { recursive: true }
        return

      build.onLoad { filter }, (args) ->
        try
          source := await readFile args.path
          filename := path.relative(process.cwd(), args.path)
          compiled := await compile source, {
            filename
            inlineMap
            js
          }

          if next and tmpPath
            outputFileName := filename + js ? '.jsx' : '.tsx'
            outputFilePath := path.join tmpPath, outputFileName

            // I'd prefer not to use temp files but I can't find a way to pass a stream to fs.readFile which is what
            // most esbuild plugins use
            await writeFile outputFilePath, compiled
            return await nextTransform {
              ...args
              path: outputFilePath
            }

          return
            contents: compiled
        catch e
          return
            errors: [{
              text: e.message
              location:
                file: args.path
                namespace: args.namespace
                line: e.line
                column: e.column
              detail: e
            }]
  }

defaultPlugin := civet()

// Default zero-config plugin
civet.setup = defaultPlugin.setup

// This gets rewritten to roughly `module.exports = civet` in `build/esbuild.civet`.
// It assumes that there are no named exports, only a default.
export default civet