import { useLocal } from "@/context"
import { Button, Icon, IconButton, Select, SelectDialog, Tooltip } from "@opencode-ai/ui"
import { useFilteredList } from "@opencode-ai/ui/hooks"
import { createEffect, on, Component, createMemo, Show, Switch, Match, For } from "solid-js"
import { createStore } from "solid-js/store"
import { FileIcon } from "@/ui"
import { getDirectory, getFilename } from "@/utils"
import { createFocusSignal } from "@solid-primitives/active-element"
import { TextSelection } from "@/context/local"
import { DateTime } from "luxon"

interface PartBase {
  content: string
}

interface TextPart extends PartBase {
  type: "text"
}

interface FileAttachmentPart extends PartBase {
  type: "file"
  path: string
  selection?: TextSelection
}

export type ContentPart = TextPart | FileAttachmentPart

interface PromptInputProps {
  onSubmit: (parts: ContentPart[]) => void
  class?: string
  ref?: (el: HTMLDivElement) => void
}

export const PromptInput: Component<PromptInputProps> = (props) => {
  const local = useLocal()
  let editorRef!: HTMLDivElement

  const defaultParts = [{ type: "text", content: "" } as const]
  const [store, setStore] = createStore<{
    contentParts: ContentPart[]
    popoverIsOpen: boolean
  }>({
    contentParts: defaultParts,
    popoverIsOpen: false,
  })

  const isEmpty = createMemo(() => isEqual(store.contentParts, defaultParts))
  const isFocused = createFocusSignal(() => editorRef)

  createEffect(() => {
    if (isFocused()) {
      handleInput()
    } else {
      setStore("popoverIsOpen", false)
    }
  })

  const { flat, active, onInput, onKeyDown } = useFilteredList<string>({
    items: local.file.search,
    key: (x) => x,
    onSelect: (path) => {
      if (!path) return
      addPart({ type: "file", path, content: "@" + getFilename(path) })
      setStore("popoverIsOpen", false)
    },
  })

  createEffect(
    on(
      () => store.contentParts,
      (currentParts) => {
        const domParts = parseFromDOM()
        if (isEqual(currentParts, domParts)) return

        const selection = window.getSelection()
        let cursorPosition: number | null = null
        if (selection && selection.rangeCount > 0 && editorRef.contains(selection.anchorNode)) {
          cursorPosition = getCursorPosition(editorRef)
        }

        editorRef.innerHTML = ""
        currentParts.forEach((part) => {
          if (part.type === "text") {
            editorRef.appendChild(document.createTextNode(part.content))
          } else if (part.type === "file") {
            const pill = document.createElement("span")
            pill.textContent = part.content
            pill.setAttribute("data-type", "file")
            pill.setAttribute("data-path", part.path)
            pill.setAttribute("contenteditable", "false")
            pill.style.userSelect = "text"
            pill.style.cursor = "default"
            editorRef.appendChild(pill)
          }
        })

        if (cursorPosition !== null) {
          setCursorPosition(editorRef, cursorPosition)
        }
      },
    ),
  )

  const parseFromDOM = (): ContentPart[] => {
    const newParts: ContentPart[] = []
    editorRef.childNodes.forEach((node) => {
      if (node.nodeType === Node.TEXT_NODE) {
        if (node.textContent) newParts.push({ type: "text", content: node.textContent })
      } else if (node.nodeType === Node.ELEMENT_NODE && (node as HTMLElement).dataset.type) {
        switch ((node as HTMLElement).dataset.type) {
          case "file":
            newParts.push({
              type: "file",
              path: (node as HTMLElement).dataset.path!,
              content: node.textContent!,
            })
            break
          default:
            break
        }
      }
    })
    if (newParts.length === 0) newParts.push(...defaultParts)
    return newParts
  }

  const handleInput = () => {
    const rawParts = parseFromDOM()
    const cursorPosition = getCursorPosition(editorRef)
    const rawText = rawParts.map((p) => p.content).join("")

    const atMatch = rawText.substring(0, cursorPosition).match(/@(\S*)$/)
    if (atMatch) {
      onInput(atMatch[1])
      setStore("popoverIsOpen", true)
    } else if (store.popoverIsOpen) {
      setStore("popoverIsOpen", false)
    }

    setStore("contentParts", rawParts)
  }

  const addPart = (part: ContentPart) => {
    const cursorPosition = getCursorPosition(editorRef)
    const rawText = store.contentParts.map((p) => p.content).join("")
    const textBeforeCursor = rawText.substring(0, cursorPosition)
    const atMatch = textBeforeCursor.match(/@(\S*)$/)
    if (!atMatch) return

    const startIndex = atMatch.index!
    const endIndex = cursorPosition

    const {
      parts: nextParts,
      cursorIndex,
      cursorOffset,
      inserted,
    } = store.contentParts.reduce(
      (acc, item) => {
        if (acc.inserted) {
          acc.parts.push(item)
          acc.runningIndex += item.content.length
          return acc
        }

        const nextIndex = acc.runningIndex + item.content.length
        if (nextIndex <= startIndex) {
          acc.parts.push(item)
          acc.runningIndex = nextIndex
          return acc
        }

        if (item.type !== "text") {
          acc.parts.push(item)
          acc.runningIndex = nextIndex
          return acc
        }

        const headLength = Math.max(0, startIndex - acc.runningIndex)
        const tailLength = Math.max(0, endIndex - acc.runningIndex)
        const head = item.content.slice(0, headLength)
        const tail = item.content.slice(tailLength)

        if (head) acc.parts.push({ type: "text", content: head })

        acc.parts.push(part)

        const rest = /^\s/.test(tail) ? tail : ` ${tail}`
        if (rest) {
          acc.cursorIndex = acc.parts.length
          acc.cursorOffset = Math.min(1, rest.length)
          acc.parts.push({ type: "text", content: rest })
        }

        acc.inserted = true
        acc.runningIndex = nextIndex
        return acc
      },
      {
        parts: [] as ContentPart[],
        runningIndex: 0,
        inserted: false,
        cursorIndex: null as number | null,
        cursorOffset: 0,
      },
    )

    if (!inserted || cursorIndex === null) return

    setStore("contentParts", nextParts)
    setStore("popoverIsOpen", false)

    queueMicrotask(() => {
      const node = editorRef.childNodes[cursorIndex]
      if (node && node.nodeType === Node.TEXT_NODE) {
        const range = document.createRange()
        const selection = window.getSelection()
        const length = node.textContent ? node.textContent.length : 0
        const offset = cursorOffset > length ? length : cursorOffset
        range.setStart(node, offset)
        range.collapse(true)
        selection?.removeAllRanges()
        selection?.addRange(range)
      }
    })
  }

  const handleKeyDown = (event: KeyboardEvent) => {
    if (store.popoverIsOpen && (event.key === "ArrowUp" || event.key === "ArrowDown" || event.key === "Enter")) {
      onKeyDown(event)
      event.preventDefault()
      return
    }
    if (event.key === "Enter" && !event.shiftKey) {
      handleSubmit(event)
    }
  }

  const handleSubmit = (event: Event) => {
    event.preventDefault()
    if (store.contentParts.length > 0) {
      props.onSubmit([...store.contentParts])
      setStore("contentParts", defaultParts)
    }
  }

  return (
    <div class="relative size-full max-w-[640px] _max-h-[320px] flex flex-col gap-3">
      <Show when={store.popoverIsOpen}>
        <div class="absolute inset-x-0 -top-3 -translate-y-full origin-bottom-left max-h-[252px] min-h-10 overflow-y-auto flex flex-col p-2 pb-0 rounded-2xl border border-border-base bg-surface-raised-stronger-non-alpha shadow-md">
          <For each={flat()}>
            {(i) => (
              <div
                classList={{
                  "w-full flex items-center justify-between rounded-md": true,
                  "bg-surface-raised-base-hover": active() === i,
                }}
              >
                <div class="flex items-center gap-x-2 grow min-w-0">
                  <FileIcon node={{ path: i, type: "file" }} class="shrink-0 size-4" />
                  <div class="flex items-center text-14-regular">
                    <span class="text-text-weak whitespace-nowrap overflow-hidden overflow-ellipsis truncate min-w-0">
                      {getDirectory(i)}/
                    </span>
                    <span class="text-text-strong whitespace-nowrap">{getFilename(i)}</span>
                  </div>
                </div>
                <div class="flex items-center gap-x-1 text-text-muted/40 shrink-0"></div>
              </div>
            )}
          </For>
        </div>
      </Show>
      <form
        onSubmit={handleSubmit}
        classList={{
          "bg-surface-raised-stronger-non-alpha border border-border-strong-base": true,
          "rounded-2xl overflow-clip focus-within:shadow-xs-border-selected": true,
          [props.class ?? ""]: !!props.class,
        }}
      >
        <div class="relative max-h-[240px] overflow-y-auto">
          <div
            ref={(el) => {
              editorRef = el
              props.ref?.(el)
            }}
            contenteditable="true"
            onInput={handleInput}
            onKeyDown={handleKeyDown}
            classList={{
              "w-full p-3 text-14-regular text-text-strong focus:outline-none whitespace-pre-wrap": true,
              "[&>[data-type=file]]:text-icon-info-active": true,
            }}
          />
          <Show when={isEmpty()}>
            <div class="absolute top-0 left-0 p-3 text-14-regular text-text-weak pointer-events-none">
              Plan and build anything
            </div>
          </Show>
        </div>
        <div class="p-3 flex items-center justify-between">
          <div class="flex items-center justify-start gap-1">
            <Select
              options={local.agent.list().map((agent) => agent.name)}
              current={local.agent.current().name}
              onSelect={local.agent.set}
              class="capitalize"
            />
            <SelectDialog
              title="Select model"
              placeholder="Search models"
              emptyMessage="No model results"
              key={(x) => `${x.provider.id}:${x.id}`}
              items={local.model.list()}
              current={local.model.current()}
              filterKeys={["provider.name", "name", "id"]}
              groupBy={(x) => x.provider.name}
              sortGroupsBy={(a, b) => {
                const order = ["opencode", "anthropic", "github-copilot", "openai", "google", "openrouter", "vercel"]
                const aProvider = a.items[0].provider.id
                const bProvider = b.items[0].provider.id
                if (order.includes(aProvider) && !order.includes(bProvider)) return -1
                if (!order.includes(aProvider) && order.includes(bProvider)) return 1
                return order.indexOf(aProvider) - order.indexOf(bProvider)
              }}
              onSelect={(x) => local.model.set(x ? { modelID: x.id, providerID: x.provider.id } : undefined)}
              trigger={
                <Button as="div" variant="ghost">
                  {local.model.current()?.name ?? "Select model"}
                  <span class="ml-0.5 text-text-weak text-12-regular">{local.model.current()?.provider.name}</span>
                  <Icon name="chevron-down" size="small" />
                </Button>
              }
            >
              {(i) => (
                <div class="w-full flex items-center justify-between gap-x-3">
                  <div class="flex items-center gap-x-2.5 text-text-muted grow min-w-0">
                    <img src={`https://models.dev/logos/${i.provider.id}.svg`} class="size-6 p-0.5 shrink-0 " />
                    <div class="flex gap-x-3 items-baseline flex-[1_0_0]">
                      <span class="text-14-medium text-text-strong overflow-hidden text-ellipsis">{i.name}</span>
                      <span class="text-12-medium text-text-weak overflow-hidden text-ellipsis truncate min-w-0">
                        {DateTime.fromFormat(i.release_date, "yyyy-MM-dd").toFormat("LLL yyyy")}
                      </span>
                    </div>
                  </div>
                  <Show when={!i.cost || i.cost?.input === 0}>
                    <div class="overflow-hidden text-12-medium text-text-strong">Free</div>
                  </Show>
                </div>
              )}
            </SelectDialog>
          </div>
          <IconButton type="submit" disabled={isEmpty()} icon="arrow-up" variant="primary" />
        </div>
      </form>
    </div>
  )
}

function isEqual(arrA: ContentPart[], arrB: ContentPart[]): boolean {
  if (arrA.length !== arrB.length) return false
  for (let i = 0; i < arrA.length; i++) {
    const partA = arrA[i]
    const partB = arrB[i]
    if (partA.type !== partB.type) return false
    if (partA.type === "text" && partA.content !== (partB as TextPart).content) {
      return false
    }
    if (partA.type === "file" && partA.path !== (partB as FileAttachmentPart).path) {
      return false
    }
  }
  return true
}

function getCursorPosition(parent: HTMLElement): number {
  const selection = window.getSelection()
  if (!selection || selection.rangeCount === 0) return 0
  const range = selection.getRangeAt(0)
  const preCaretRange = range.cloneRange()
  preCaretRange.selectNodeContents(parent)
  preCaretRange.setEnd(range.startContainer, range.startOffset)
  return preCaretRange.toString().length
}

function setCursorPosition(parent: HTMLElement, position: number) {
  let remaining = position
  let node = parent.firstChild
  while (node) {
    const length = node.textContent ? node.textContent.length : 0
    const isText = node.nodeType === Node.TEXT_NODE
    const isFile = node.nodeType === Node.ELEMENT_NODE && (node as HTMLElement).dataset.type === "file"

    if (isText && remaining <= length) {
      const range = document.createRange()
      const selection = window.getSelection()
      range.setStart(node, remaining)
      range.collapse(true)
      selection?.removeAllRanges()
      selection?.addRange(range)
      return
    }

    if (isFile && remaining <= length) {
      const range = document.createRange()
      const selection = window.getSelection()
      range.setStartAfter(node)
      range.collapse(true)
      selection?.removeAllRanges()
      selection?.addRange(range)
      return
    }

    remaining -= length
    node = node.nextSibling
  }

  const fallbackRange = document.createRange()
  const fallbackSelection = window.getSelection()
  const last = parent.lastChild
  if (last && last.nodeType === Node.TEXT_NODE) {
    const len = last.textContent ? last.textContent.length : 0
    fallbackRange.setStart(last, len)
  }
  if (!last || last.nodeType !== Node.TEXT_NODE) {
    fallbackRange.selectNodeContents(parent)
  }
  fallbackRange.collapse(false)
  fallbackSelection?.removeAllRanges()
  fallbackSelection?.addRange(fallbackRange)
}