#!/usr/bin/env bun
import { existsSync, readFileSync, writeFileSync } from 'node:fs'
import { homedir } from 'node:os'
import { dirname, join } from 'node:path'

const configurationFile = '.env-variables'
const configurationPath = join(homedir(), 'Library/Mobile Documents/com~apple~CloudDocs/Documents', configurationFile)

if (!existsSync(dirname(configurationPath))) {
  console.log('Cannot find iCloud folder, make sure to enable synchronization.')
  process.exit(1)
}

// Example: { epic-language: ['OPENAI_API_KEY=123'] }
const configuration: { [key: string]: string[] } = {}
const projectName = process.cwd()

if (!projectName) {
  console.log(`Cannot find the current project in "${process.cwd()}".`)
  process.exit(1)
}

function parseConfiguration(contents: string) {
  let currentProject: string | undefined
  const lines = contents.split('\n')

  for (const line of lines) {
    const trimmedLine = line.trim()

    // Check if the line is a project declaration
    const projectMatch = trimmedLine.match(/^([^:]+):$/)
    if (projectMatch) {
      ;[, currentProject] = projectMatch
      configuration[currentProject as string] = []
    } else if (line !== '') {
      // Parse lines for the current project
      const current = configuration[currentProject as string]
      current?.push(line)
    }
  }
}

function createConfigurationTemplate() {
  let lines = '# Configuration managed by epic-cli\n\n'
  const projects = Object.entries(configuration)

  projects.forEach(([project, contents], index) => {
    lines += `${project}:\n\n`
    lines += contents.join('\n')
    if (index !== projects.length - 1) {
      lines += '\n'
    }
  })

  return lines
}

function parseDotenvFile(content: string) {
  const lines = content.split('\n')
  // Skip comments and empty lines
  return lines.filter((line) => line.trim() !== '')
}

function processComments(lines: string[]) {
  const regularLines: string[] = []
  const comments: string[] = []
  for (const line of lines) {
    const trimmed = line.trim()
    if (trimmed.startsWith('#')) {
      comments.push(trimmed)
      continue
    }

    // Find the first # that's not in quotes and not escaped
    let inQuotes = false
    let quoteChar = ''
    let commentFound = false

    for (let i = 0; i < trimmed.length; i++) {
      const char = trimmed[i]
      const prevChar = trimmed[i - 1]

      if ((char === '"' || char === "'") && prevChar !== '\\') {
        if (!inQuotes) {
          inQuotes = true
          quoteChar = char
        } else if (char === quoteChar) {
          inQuotes = false
        }
      }

      if (char === '#' && !inQuotes && prevChar !== '\\') {
        const regularPart = trimmed.slice(0, i)
        const commentPart = trimmed.slice(i)
        comments.push(commentPart)
        regularLines.push(regularPart)
        commentFound = true
      }
    }

    if (!commentFound) {
      regularLines.push(trimmed)
    }
  }

  if (comments.length === 0) {
    return regularLines
  }

  const readmePath = join(process.cwd(), 'README.md')

  if (!existsSync(readmePath)) {
    console.warn('Please remove comments from the .env file and try again.')
    process.exit(1)
  }

  const readme = readFileSync(readmePath, 'utf-8')
  const newContent = `${readme}\n\n## Comments from Environment Variables\n${comments.join('\n')}`
  writeFileSync(readmePath, newContent)
  console.log('Comments in .env not supported have been moved to the end of your README.md.')

  return regularLines
}

if (existsSync(configurationPath)) {
  console.log(`Found existing configuration in iCloud » Documents » ${configurationFile}`)
  parseConfiguration(readFileSync(configurationPath, 'utf-8'))
} else {
  console.log(`Configuration file created in iCloud » Documents » ${configurationFile}`)
  const emptyTemplate = createConfigurationTemplate()
  writeFileSync(configurationPath, emptyTemplate)
}

if (process.argv.includes('--list')) {
  console.log(configuration)
  process.exit(0)
}

const projectMissing = !configuration[projectName]

if (projectMissing) {
  configuration[projectName] = []
}

const dotEnvPath = join(process.cwd(), '.env')

if (existsSync(dotEnvPath)) {
  const localConfiguration = parseDotenvFile(readFileSync(dotEnvPath, 'utf-8'))
  const withoutComments = processComments(localConfiguration)
  // Merge configurations, local takes precedence, in case it was edited.
  Object.assign(configuration[projectName] as object, withoutComments)
} else if (projectMissing) {
  console.log('No existing configuration for this project or .env file found!')
}

const updatedTemplate = createConfigurationTemplate()
writeFileSync(configurationPath, updatedTemplate)

if (configuration[projectName] && configuration[projectName].length > 0) {
  writeFileSync(dotEnvPath, configuration[projectName]?.join('\n') as string) // ?.join('\n')
}