import fs from "node:fs"
import path from "node:path"

const root = process.cwd()
const contentDir = path.join(root, "site/src/content/components")
const uiDir = path.join(root, "src/components/ui")
const examplesDir = path.join(root, "site/src/examples/components")
const finished = new Set(["menu", "context-menu", "navigation-menu"])

const names = {
  "alert-dialog": "AlertDialog",
  "checkbox-group": "CheckboxGroup",
  "context-menu": "ContextMenu",
  "navigation-menu": "NavigationMenu",
  "number-field": "NumberField",
  "otp-field": "OtpField",
  "preview-card": "PreviewCard",
  "scroll-area": "ScrollArea",
  "toggle-group": "ToggleGroup",
}

const officialSlugs = {
  "otp-field": "otp-field",
}

for (const file of fs.readdirSync(contentDir).sort()) {
  if (!file.endsWith(".mdx")) continue

  const slug = file.replace(/\.mdx$/, "")
  if (finished.has(slug)) continue

  const filePath = path.join(contentDir, file)
  const current = fs.readFileSync(filePath, "utf8")
  const title = current.match(/^# (.+)$/m)?.[1] ?? titleCase(slug)
  const component = names[slug] ?? title.replace(/[^A-Za-z0-9]/g, "")
  const parts = readParts(slug)
  const exampleSrc = `components/${slug}/${slug}.tsx`
  const hasTopExample = fs.existsSync(path.join(examplesDir, slug, `${slug}.tsx`))
  const intro = readIntro(current, title)
  const baseStyle = readSectionCode(current, "Base UI Style") ?? makeBaseStyle(slug, component, parts)
  const shadcnStyle =
    readSectionCode(current, "Shadcn Style") ??
    readSectionCode(current, "Named Import Style") ??
    makeNamedStyle(slug, component, parts)
  const examples = readExamples(current, title, slug, exampleSrc, hasTopExample)

  const next = [
    `# ${title}`,
    "",
    intro || `${title} wraps Base UI's ${title.toLowerCase()} primitive with the Tailwind classes from the official Base UI example.`,
    "",
    hasTopExample ? `::example{src="${exampleSrc}"}` : "",
    "",
    "## Anatomy",
    "",
    "### Base UI Style",
    "",
    fenced(baseStyle),
    "",
    "### Shadcn Style",
    "",
    fenced(shadcnStyle),
    "",
    "## Composition",
    "",
    `Use the following composition to build \`${component}\`:`,
    "",
    "```txt",
    makeComposition(component, parts).join("\n"),
    "```",
    "",
    "## Examples",
    "",
    examples.trim(),
    "",
    makeApi(slug, title, component, parts),
    "",
  ]
    .filter((line, index, array) => !(line === "" && array[index - 1] === ""))
    .join("\n")

  fs.writeFileSync(filePath, next)
}

function readParts(slug) {
  const indexPath = path.join(uiDir, slug, "index.ts")
  if (!fs.existsSync(indexPath)) return ["Root"]

  const source = fs.readFileSync(indexPath, "utf8")
  const objectMatch = source.match(/const\s+\w+\s*=\s*\{([\s\S]*?)\n\}/)
  if (!objectMatch) return ["Root"]

  const parts = []
  for (const line of objectMatch[1].split("\n")) {
    const match = line.match(/^\s*([A-Za-z][A-Za-z0-9]*):/)
    if (!match) continue
    const part = match[1]
    if (part[0] === part[0].toLowerCase()) continue
    if (!parts.includes(part)) parts.push(part)
  }
  return parts.length ? parts : ["Root"]
}

function readIntro(source, title) {
  const start = source.indexOf(`# ${title}`)
  if (start === -1) return ""
  let rest = source.slice(start + title.length + 3)
  const stops = ["\n<ComponentPreview", "\nexport ", "\n## ", "\n::example"]
  let end = rest.length
  for (const stop of stops) {
    const index = rest.indexOf(stop)
    if (index !== -1 && index < end) end = index
  }
  rest = rest.slice(0, end)
  return rest
    .replace(/^import .+$/gm, "")
    .replace(/\n{3,}/g, "\n\n")
    .trim()
}

function readSectionCode(source, heading) {
  const start = source.indexOf(`## ${heading}`)
  if (start === -1) return null
  const fenceStart = source.indexOf("```", start)
  if (fenceStart === -1) return null
  const lineEnd = source.indexOf("\n", fenceStart)
  const fenceEnd = source.indexOf("\n```", lineEnd)
  if (fenceEnd === -1) return null
  return source.slice(lineEnd + 1, fenceEnd).trim()
}

function readExamples(source, title, slug, exampleSrc, hasTopExample) {
  const start = source.indexOf("## Examples")
  if (start === -1) return ""
  const nextHeading = source.slice(start + 1).search(/\n## /)
  const end = nextHeading === -1 ? source.length : start + 1 + nextHeading

  let content = source.slice(start + "## Examples".length, end).trim()
  if (hasTopExample) {
    const escapedTitle = escapeRegExp(title)
    const escapedSrc = escapeRegExp(exampleSrc)
    const duplicate = new RegExp(`^### ${escapedTitle}\\n\\n::example\\{src="${escapedSrc}"\\}\\n*`, "m")
    content = content.replace(duplicate, "").trim()
  }
  return content || "No additional examples yet."
}

function makeBaseStyle(slug, component, parts) {
  const lines = [`import ${component} from "@/components/ui/${slug}"`, "", `<${component}.Root>`]
  for (const part of parts.filter((part) => part !== "Root").slice(0, 5)) {
    lines.push(`  <${component}.${part} />`)
  }
  lines.push(`</${component}.Root>`)
  return lines.join("\n")
}

function makeNamedStyle(slug, component, parts) {
  const named = parts.map((part) => (part === "Root" ? component : `${component}${part}`))
  return [
    "import {",
    ...named.slice(0, 8).map((name) => `  ${name},`),
    `} from "@/components/ui/${slug}"`,
  ].join("\n")
}

function makeComposition(component, parts) {
  const has = (part) => parts.includes(part)
  const portalChildren = []
  if (has("Backdrop")) portalChildren.push(`${component}Backdrop`)
  if (has("Positioner")) {
    const popupChildren = []
    for (const part of ["Arrow", "Viewport", "List", "Collection", "Group", "Item", "Empty"]) {
      if (has(part)) popupChildren.push(`${component}${part}`)
    }
    portalChildren.push({
      label: `${component}Positioner`,
      children: has("Popup") ? [{ label: `${component}Popup`, children: popupChildren }] : popupChildren,
    })
  } else if (has("Popup")) {
    portalChildren.push(`${component}Popup`)
  }

  const children = []
  const leading = ["Trigger", "Label", "Input", "Control", "Track", "Thumb", "Image", "Fallback", "Group"]
  for (const part of leading) {
    if (has(part)) children.push(`${component}${part}`)
  }
  if (has("Portal")) {
    children.push({ label: `${component}Portal`, children: portalChildren })
  }
  for (const part of parts) {
    if (part === "Root" || leading.includes(part) || part === "Portal" || part === "Backdrop" || part === "Positioner" || part === "Popup") {
      continue
    }
    const label = part === "Separator" ? `${component}.Separator` : `${component}${part}`
    if (!treeHas(children, label)) children.push(label)
  }
  return renderTree({ label: component, children })
}

function treeHas(children, label) {
  for (const child of children) {
    if (typeof child === "string" && child === label) return true
    if (typeof child === "object") {
      if (child.label === label) return true
      if (treeHas(child.children ?? [], label)) return true
    }
  }
  return false
}

function renderTree(node, prefix = "") {
  const lines = [prefix ? `${prefix}${node.label}` : node.label]
  const children = node.children ?? []
  children.forEach((child, index) => {
    const last = index === children.length - 1
    const branch = last ? "└── " : "├── "
    const nextPrefix = prefix + (last ? "    " : "│   ")
    if (typeof child === "string") {
      lines.push(`${prefix}${branch}${child}`)
    } else {
      lines.push(`${prefix}${branch}${child.label}`)
      lines.push(...renderChildren(child.children ?? [], nextPrefix))
    }
  })
  return lines
}

function renderChildren(children, prefix) {
  const lines = []
  children.forEach((child, index) => {
    const last = index === children.length - 1
    const branch = last ? "└── " : "├── "
    const nextPrefix = prefix + (last ? "    " : "│   ")
    if (typeof child === "string") {
      lines.push(`${prefix}${branch}${child}`)
    } else {
      lines.push(`${prefix}${branch}${child.label}`)
      lines.push(...renderChildren(child.children ?? [], nextPrefix))
    }
  })
  return lines
}

function makeApi(slug, title, component, parts) {
  const official = `https://base-ui.com/react/components/${officialSlugs[slug] ?? slug}#api-reference`
  const sections = parts.map((part) => makeApiPart(component, part)).join("\n\n")
  return [
    "## API Reference",
    "",
    `Official API: [Base UI ${title} API](${official}).`,
    "",
    `This wrapper preserves the underlying Base UI ${title} API. Styled parts forward \`className\`, \`style\`, and \`render\` where Base UI supports them.`,
    "",
    sections,
  ].join("\n")
}

function makeApiPart(component, part) {
  const heading = part === "Root" ? "Root" : part
  const label = part === "Root" ? component : `${component}.${part}`
  const rows = apiRows(part)
  return [
    `### ${heading}`,
    "",
    `\`${label}\` exposes the corresponding Base UI part with the wrapper's Tailwind styles.`,
    "",
    "| Prop | Type | Default | Description |",
    "| --- | --- | --- | --- |",
    ...rows,
  ].join("\n")
}

function apiRows(part) {
  if (part === "Root") {
    return [
      "| `defaultValue` / `defaultOpen` | `any` | - | Initial uncontrolled value or open state when supported. |",
      "| `value` / `open` | `any` | - | Controlled value or open state when supported. |",
      "| `onValueChange` / `onOpenChange` | `function` | - | Called when controlled state changes. |",
      "| `children` | `React.ReactNode` | - | Child parts rendered inside the root. |",
    ]
  }
  if (part === "Portal") {
    return [
      "| `container` | `HTMLElement \\| RefObject<HTMLElement>` | `document.body` | Element that receives portal content. |",
      "| `keepMounted` | `boolean` | `false` | Keeps children mounted when closed. |",
      "| `children` | `React.ReactNode` | - | Floating content. |",
    ]
  }
  if (part === "Positioner") {
    return [
      "| `side` | `Side` | - | Preferred side for floating content. |",
      "| `align` | `Align` | - | Alignment on the selected side. |",
      "| `sideOffset` | `number \\| OffsetFunction` | `0` | Distance from the anchor. |",
      "| `collisionAvoidance` | `CollisionAvoidance` | - | Controls flip and shift behavior. |",
      "| `className` | `string \\| (state) => string` | - | Classes for placement state. |",
    ]
  }
  if (["Trigger", "Item", "LinkItem", "Link", "Button", "Close", "Action"].includes(part)) {
    return [
      "| `disabled` | `boolean` | `false` | Prevents user interaction when supported. |",
      "| `onClick` | `function` | - | Called when the element is pressed. |",
      "| `className` | `string \\| (state) => string` | - | Classes for interactive state. |",
      "| `render` | `ReactElement \\| (props, state) => ReactElement` | - | Replaces the rendered element. |",
      "| `children` | `React.ReactNode` | - | Visible content. |",
    ]
  }
  if (["CheckboxItem", "RadioGroup", "RadioItem"].includes(part)) {
    return [
      "| `checked` / `value` | `any` | - | Controlled checked or selected state when supported. |",
      "| `defaultChecked` / `defaultValue` | `any` | - | Initial uncontrolled state when supported. |",
      "| `onCheckedChange` / `onValueChange` | `function` | - | Called when selection changes. |",
      "| `disabled` | `boolean` | `false` | Prevents user interaction. |",
      "| `className` | `string \\| (state) => string` | - | Classes for checked, highlighted, and disabled state. |",
    ]
  }
  return [
    "| `className` | `string \\| (state) => string` | - | Classes for the part state. |",
    "| `style` | `React.CSSProperties \\| (state) => React.CSSProperties` | - | Inline style or state-based style. |",
    "| `render` | `ReactElement \\| (props, state) => ReactElement` | - | Replaces the rendered element when supported. |",
    "| `children` | `React.ReactNode` | - | Child content when the part accepts children. |",
  ]
}

function fenced(value) {
  return ["```tsx", value.trim(), "```"].join("\n")
}

function titleCase(slug) {
  return slug
    .split("-")
    .map((word) => word[0].toUpperCase() + word.slice(1))
    .join(" ")
}

function escapeRegExp(value) {
  return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")
}