import type { Message } from "../types/message"

import { resolvePastedPlaceholders } from "../lib/prompt-placeholders"
import { instances } from "./instances"

import {
  addRecentModelPreference,
  preferences,
  setAgentModelPreference,
} from "./preferences"
import { sessions, withSession } from "./session-state"
import { getDefaultModel, isModelValid } from "./session-models"
import {
  computeDisplayParts,
  getSessionIndex,
  initializePartVersion,
  updateSessionInfo,
} from "./session-messages"

const ID_LENGTH = 26
const BASE62_CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"

let lastTimestamp = 0
let localCounter = 0

function randomBase62(length: number): string {
  let result = ""
  const cryptoObj = (globalThis as unknown as { crypto?: Crypto }).crypto
  if (cryptoObj && typeof cryptoObj.getRandomValues === "function") {
    const bytes = new Uint8Array(length)
    cryptoObj.getRandomValues(bytes)
    for (let i = 0; i < length; i++) {
      result += BASE62_CHARS[bytes[i] % BASE62_CHARS.length]
    }
  } else {
    for (let i = 0; i < length; i++) {
      const idx = Math.floor(Math.random() * BASE62_CHARS.length)
      result += BASE62_CHARS[idx]
    }
  }
  return result
}

function createId(prefix: string): string {
  const timestamp = Date.now()
  if (timestamp !== lastTimestamp) {
    lastTimestamp = timestamp
    localCounter = 0
  }
  localCounter++

  const value = (BigInt(timestamp) << BigInt(12)) + BigInt(localCounter)
  const bytes = new Array<number>(6)
  for (let i = 0; i < 6; i++) {
    const shift = BigInt(8 * (5 - i))
    bytes[i] = Number((value >> shift) & BigInt(0xff))
  }
  const hex = bytes.map((b) => b.toString(16).padStart(2, "0")).join("")
  const random = randomBase62(ID_LENGTH - 12)

  return `${prefix}_${hex}${random}`
}

async function sendMessage(
  instanceId: string,
  sessionId: string,
  prompt: string,
  attachments: any[] = [],
): Promise<void> {
  const instance = instances().get(instanceId)
  if (!instance || !instance.client) {
    throw new Error("Instance not ready")
  }

  const instanceSessions = sessions().get(instanceId)
  const session = instanceSessions?.get(sessionId)
  if (!session) {
    throw new Error("Session not found")
  }

  const messageId = createId("msg")
  const textPartId = createId("part")

  const resolvedPrompt = resolvePastedPlaceholders(prompt, attachments)

  const optimisticParts: any[] = [
    {
      id: textPartId,
      type: "text" as const,
      text: resolvedPrompt,
      synthetic: true,
      renderCache: undefined,
    },
  ]

  const optimisticMessage: Message = {
    id: messageId,
    sessionId,
    type: "user",
    parts: optimisticParts,
    timestamp: Date.now(),
    status: "sending",
    version: 0,
  }

  optimisticParts.forEach((part: any) => initializePartVersion(part))

  optimisticMessage.displayParts = computeDisplayParts(optimisticMessage, preferences().showThinkingBlocks)

  withSession(instanceId, sessionId, (session) => {
    session.messages.push(optimisticMessage)
    const index = getSessionIndex(instanceId, sessionId)
    index.messageIndex.set(optimisticMessage.id, session.messages.length - 1)
  })

  const requestParts: any[] = [
    {
      id: textPartId,
      type: "text" as const,
      text: resolvedPrompt,
    },
  ]

  if (attachments.length > 0) {
    for (const att of attachments) {
      const source = att.source
      if (source.type === "file") {
        const partId = createId("part")
        requestParts.push({
          id: partId,
          type: "file" as const,
          url: att.url,
          mime: source.mime,
          filename: att.filename,
        })
        optimisticParts.push({
          id: partId,
          type: "file" as const,
          url: att.url,
          mime: source.mime,
          filename: att.filename,
          synthetic: true,
        })
      } else if (source.type === "text") {
        const display: string | undefined = att.display
        const value: unknown = source.value
        const isPastedPlaceholder = typeof display === "string" && /^pasted #\d+/.test(display)

        if (isPastedPlaceholder || typeof value !== "string") {
          continue
        }

        const partId = createId("part")
        requestParts.push({
          id: partId,
          type: "text" as const,
          text: value,
        })
        optimisticParts.push({
          id: partId,
          type: "text" as const,
          text: value,
          synthetic: true,
          renderCache: undefined,
        })
      }
    }
  }

  const requestBody = {
    messageID: messageId,
    parts: requestParts,
    ...(session.agent && { agent: session.agent }),
    ...(session.model.providerId &&
      session.model.modelId && {
        model: {
          providerID: session.model.providerId,
          modelID: session.model.modelId,
        },
      }),
  }

  console.log("[sendMessage] Sending prompt:", {
    sessionId,
    requestBody,
  })

  try {
    console.log(`[HTTP] POST /session.prompt for instance ${instanceId}`, { sessionId, requestBody })
    const response = await instance.client.session.prompt({
      path: { id: sessionId },
      body: requestBody,
    })

    console.log("[sendMessage] Response:", response)

    if (response.error) {
      console.error("[sendMessage] Server returned error:", response.error)
      throw new Error(JSON.stringify(response.error) || "Failed to send message")
    }
  } catch (error) {
    console.error("[sendMessage] Failed to send prompt:", error)
    throw error
  }
}

async function executeCustomCommand(
  instanceId: string,
  sessionId: string,
  commandName: string,
  args: string,
): Promise<void> {
  const instance = instances().get(instanceId)
  if (!instance || !instance.client) {
    throw new Error("Instance not ready")
  }

  const session = sessions().get(instanceId)?.get(sessionId)
  if (!session) {
    throw new Error("Session not found")
  }

  const body: {
    command: string
    arguments: string
    messageID: string
    agent?: string
    model?: string
  } = {
    command: commandName,
    arguments: args,
    messageID: createId("msg"),
  }

  if (session.agent) {
    body.agent = session.agent
  }

  if (session.model.providerId && session.model.modelId) {
    body.model = `${session.model.providerId}/${session.model.modelId}`
  }

  await instance.client.session.command({
    path: { id: sessionId },
    body,
  })
}

async function runShellCommand(instanceId: string, sessionId: string, command: string): Promise<void> {
  const instance = instances().get(instanceId)
  if (!instance || !instance.client) {
    throw new Error("Instance not ready")
  }

  const session = sessions().get(instanceId)?.get(sessionId)
  if (!session) {
    throw new Error("Session not found")
  }

  const agent = session.agent || "build"

  await instance.client.session.shell({
    path: { id: sessionId },
    body: {
      agent,
      command,
    },
  })
}

async function abortSession(instanceId: string, sessionId: string): Promise<void> {
  const instance = instances().get(instanceId)
  if (!instance || !instance.client) {
    throw new Error("Instance not ready")
  }

  console.log("[abortSession] Aborting session:", { instanceId, sessionId })

  try {
    console.log(`[HTTP] POST /session.abort for instance ${instanceId}`, { sessionId })
    await instance.client.session.abort({
      path: { id: sessionId },
    })
    console.log("[abortSession] Session aborted successfully")
  } catch (error) {
    console.error("[abortSession] Failed to abort session:", error)
    throw error
  }
}

async function updateSessionAgent(instanceId: string, sessionId: string, agent: string): Promise<void> {
  const instanceSessions = sessions().get(instanceId)
  const session = instanceSessions?.get(sessionId)
  if (!session) {
    throw new Error("Session not found")
  }

  const nextModel = await getDefaultModel(instanceId, agent)
  const shouldApplyModel = isModelValid(instanceId, nextModel)

  withSession(instanceId, sessionId, (current) => {
    current.agent = agent
    if (shouldApplyModel) {
      current.model = nextModel
    }
  })

  if (agent && shouldApplyModel) {
    setAgentModelPreference(instanceId, agent, nextModel)
  }

  if (shouldApplyModel) {
    updateSessionInfo(instanceId, sessionId)
  }
}

async function updateSessionModel(
  instanceId: string,
  sessionId: string,
  model: { providerId: string; modelId: string },
): Promise<void> {
  const instanceSessions = sessions().get(instanceId)
  const session = instanceSessions?.get(sessionId)
  if (!session) {
    throw new Error("Session not found")
  }

  if (!isModelValid(instanceId, model)) {
    console.warn("Invalid model selection", model)
    return
  }

  withSession(instanceId, sessionId, (current) => {
    current.model = model
  })

  if (session.agent) {
    setAgentModelPreference(instanceId, session.agent, model)
  }
  addRecentModelPreference(model)

  updateSessionInfo(instanceId, sessionId)
}

export {
  abortSession,
  executeCustomCommand,
  runShellCommand,
  sendMessage,
  updateSessionAgent,
  updateSessionModel,
}