import { createSimpleContext } from "@opencode-ai/ui/context"
import { type Accessor, batch, createEffect, createMemo, onCleanup } from "solid-js"
import { createStore } from "solid-js/store"
import { usePlatform } from "@/context/platform"
import { Persist, persisted } from "@/utils/persist"
import { checkServerHealth } from "@/utils/server-health"

type StoredProject = { worktree: string; expanded: boolean }
const HEALTH_POLL_INTERVAL_MS = 10_000

export function normalizeServerUrl(input: string) {
  const trimmed = input.trim()
  if (!trimmed) return
  const withProtocol = /^https?:\/\//.test(trimmed) ? trimmed : `http://${trimmed}`
  return withProtocol.replace(/\/+$/, "")
}

export function serverDisplayName(conn?: ServerConnection.Any) {
  if (!conn) return ""
  if (conn.displayName) return conn.displayName
  return conn.http.url.replace(/^https?:\/\//, "").replace(/\/+$/, "")
}

function projectsKey(key: ServerConnection.Key) {
  if (!key) return ""
  if (key === "sidecar") return "local"
  const host = key.replace(/^https?:\/\//, "").split(":")[0]
  if (host === "localhost" || host === "127.0.0.1") return "local"
  return key
}

export namespace ServerConnection {
  type Base = { displayName?: string }

  export type HttpBase = {
    url: string
    username?: string
    password?: string
  }

  // Regular web connections
  export type Http = {
    type: "http"
    http: HttpBase
  } & Base

  export type Sidecar = {
    type: "sidecar"
    http: HttpBase
  } & (
    | // Regular desktop server
    { variant: "base" }
    // WSL server (windows only)
    | {
        variant: "wsl"
        distro: string
      }
  ) &
    Base

  // Remote server desktop can SSH into
  export type Ssh = {
    type: "ssh"
    host: string
    // SSH client exposes an HTTP server for the app to use as a proxy
    http: HttpBase
  } & Base

  export type Any =
    | Http
    // All these are desktop-only
    | (Sidecar | Ssh)

  export const key = (conn: Any): Key => {
    switch (conn.type) {
      case "http":
        return Key.make(conn.http.url)
      case "sidecar": {
        if (conn.variant === "wsl") return Key.make(`wsl:${conn.distro}`)
        return Key.make("sidecar")
      }
      case "ssh":
        return Key.make(`ssh:${conn.host}`)
    }
  }

  export type Key = string & { _brand: "Key" }
  export const Key = { make: (v: string) => v as Key }
}

export const { use: useServer, provider: ServerProvider } = createSimpleContext({
  name: "Server",
  init: (props: { defaultServer: ServerConnection.Key; servers?: Array<ServerConnection.Any> }) => {
    const platform = usePlatform()

    const [store, setStore, _, ready] = persisted(
      Persist.global("server", ["server.v3"]),
      createStore({
        list: [] as string[],
        projects: {} as Record<string, StoredProject[]>,
        lastProject: {} as Record<string, string>,
      }),
    )

    const allServers = createMemo(
      (): Array<ServerConnection.Any> => [
        ...(props.servers ?? []),
        ...store.list.map((value) => ({
          type: "http" as const,
          http: typeof value === "string" ? { url: value } : value,
        })),
      ],
    )

    const [state, setState] = createStore({
      active: props.defaultServer,
      healthy: undefined as boolean | undefined,
    })

    const healthy = () => state.healthy

    function startHealthPolling(conn: ServerConnection.Any) {
      let alive = true
      let busy = false

      const run = () => {
        if (busy) return
        busy = true
        void check(conn)
          .then((next) => {
            if (!alive) return
            setState("healthy", next)
          })
          .finally(() => {
            busy = false
          })
      }

      run()
      const interval = setInterval(run, HEALTH_POLL_INTERVAL_MS)
      return () => {
        alive = false
        clearInterval(interval)
      }
    }

    function setActive(input: ServerConnection.Key) {
      if (state.active !== input) setState("active", input)
    }

    function add(input: string) {
      const url = normalizeServerUrl(input)
      if (!url) return
      return batch(() => {
        const http: ServerConnection.HttpBase = { url }
        if (!store.list.includes(url)) {
          setStore("list", store.list.length, url)
        }
        const conn: ServerConnection.Http = { type: "http", http }
        setState("active", ServerConnection.key(conn))
        return conn
      })
    }

    function remove(key: ServerConnection.Key) {
      const list = store.list.filter((x) => x !== key)
      batch(() => {
        setStore("list", list)
        if (state.active === key) {
          const next = list[0]
          setState("active", next ? ServerConnection.key({ type: "http", http: { url: next } }) : props.defaultServer)
        }
      })
    }

    const isReady = createMemo(() => ready() && !!state.active)

    const fetcher = platform.fetch ?? globalThis.fetch
    const check = (conn: ServerConnection.Any) => checkServerHealth(conn.http, fetcher).then((x) => x.healthy)

    createEffect(() => {
      const current_ = current()
      if (!current_) return

      setState("healthy", undefined)
      onCleanup(startHealthPolling(current_))
    })

    const origin = createMemo(() => projectsKey(state.active))
    const projectsList = createMemo(() => store.projects[origin()] ?? [])
    const current: Accessor<ServerConnection.Any | undefined> = createMemo(
      () => allServers().find((s) => ServerConnection.key(s) === state.active) ?? allServers()[0],
    )
    const isLocal = createMemo(() => {
      const c = current()
      return c?.type === "sidecar" && c.variant === "base"
    })

    return {
      ready: isReady,
      healthy,
      isLocal,
      get key() {
        return state.active
      },
      get name() {
        return serverDisplayName(current())
      },
      get list() {
        return allServers()
      },
      get current() {
        return current()
      },
      setActive,
      add,
      remove,
      projects: {
        list: projectsList,
        open(directory: string) {
          const key = origin()
          if (!key) return
          const current = store.projects[key] ?? []
          if (current.find((x) => x.worktree === directory)) return
          setStore("projects", key, [{ worktree: directory, expanded: true }, ...current])
        },
        close(directory: string) {
          const key = origin()
          if (!key) return
          const current = store.projects[key] ?? []
          setStore(
            "projects",
            key,
            current.filter((x) => x.worktree !== directory),
          )
        },
        expand(directory: string) {
          const key = origin()
          if (!key) return
          const current = store.projects[key] ?? []
          const index = current.findIndex((x) => x.worktree === directory)
          if (index !== -1) setStore("projects", key, index, "expanded", true)
        },
        collapse(directory: string) {
          const key = origin()
          if (!key) return
          const current = store.projects[key] ?? []
          const index = current.findIndex((x) => x.worktree === directory)
          if (index !== -1) setStore("projects", key, index, "expanded", false)
        },
        move(directory: string, toIndex: number) {
          const key = origin()
          if (!key) return
          const current = store.projects[key] ?? []
          const fromIndex = current.findIndex((x) => x.worktree === directory)
          if (fromIndex === -1 || fromIndex === toIndex) return
          const result = [...current]
          const [item] = result.splice(fromIndex, 1)
          result.splice(toIndex, 0, item)
          setStore("projects", key, result)
        },
        last() {
          const key = origin()
          if (!key) return
          return store.lastProject[key]
        },
        touch(directory: string) {
          const key = origin()
          if (!key) return
          setStore("lastProject", key, directory)
        },
      },
    }
  },
})
