import { ref, computed } from "vue";
import { defineStore } from "pinia";
import {
  apiGet,
  apiPost,
  apiPatch,
  apiDelete,
  apiStreamPost,
} from "@/api/client";
import type {
  Conversation,
  ConversationDetail,
  Message,
  OllamaModel,
  OllamaStatus,
} from "@/types/chat";

export const useChatStore = defineStore("chat", () => {
  const conversations = ref<Conversation[]>([]);
  const currentConversation = ref<ConversationDetail | null>(null);
  const total = ref(0);
  const loading = ref(false);
  const streaming = ref(false);
  const streamingContent = ref("");
  const models = ref<OllamaModel[]>([]);
  const ollamaStatus = ref<"checking" | "available" | "unavailable">("checking");
  const modelStatus = ref<"checking" | "ready" | "not_found">("checking");
  const defaultModel = ref("");
  let statusPollTimer: ReturnType<typeof setInterval> | null = null;

  const chatReady = computed(
    () => ollamaStatus.value === "available" && modelStatus.value === "ready"
  );

  async function fetchConversations(limit = 50, offset = 0) {
    loading.value = true;
    try {
      const data = await apiGet<{ conversations: Conversation[]; total: number }>(
        `/api/chat/conversations?limit=${limit}&offset=${offset}`
      );
      conversations.value = data.conversations;
      total.value = data.total;
    } finally {
      loading.value = false;
    }
  }

  async function createConversation(
    title = "",
    model = ""
  ): Promise<Conversation> {
    const conv = await apiPost<Conversation>("/api/chat/conversations", {
      title,
      model,
    });
    conversations.value.unshift(conv);
    return conv;
  }

  async function fetchConversation(id: number) {
    loading.value = true;
    try {
      currentConversation.value = await apiGet<ConversationDetail>(
        `/api/chat/conversations/${id}`
      );
    } finally {
      loading.value = false;
    }
  }

  async function deleteConversation(id: number) {
    await apiDelete(`/api/chat/conversations/${id}`);
    conversations.value = conversations.value.filter((c) => c.id !== id);
    if (currentConversation.value?.id === id) {
      currentConversation.value = null;
    }
  }

  async function updateTitle(id: number, title: string) {
    const updated = await apiPatch<Conversation>(
      `/api/chat/conversations/${id}`,
      { title }
    );
    const idx = conversations.value.findIndex((c) => c.id === id);
    if (idx !== -1) {
      conversations.value[idx] = { ...conversations.value[idx], ...updated };
    }
    if (currentConversation.value?.id === id) {
      currentConversation.value.title = updated.title;
    }
  }

  async function sendMessage(content: string, contextNoteId?: number | null) {
    if (!currentConversation.value) return;

    const convId = currentConversation.value.id;

    // Add optimistic user message
    const userMsg: Message = {
      id: -Date.now(), // Temporary ID
      conversation_id: convId,
      role: "user",
      content,
      context_note_id: contextNoteId ?? null,
      created_at: new Date().toISOString(),
    };
    currentConversation.value.messages.push(userMsg);

    streaming.value = true;
    streamingContent.value = "";

    try {
      await apiStreamPost(
        `/api/chat/conversations/${convId}/messages`,
        { content, context_note_id: contextNoteId },
        (data) => {
          if (data.chunk) {
            streamingContent.value += data.chunk as string;
          }
          if (data.done) {
            // Add the final assistant message
            const assistantMsg: Message = {
              id: data.message_id as number,
              conversation_id: convId,
              role: "assistant",
              content: streamingContent.value,
              context_note_id: null,
              created_at: new Date().toISOString(),
            };
            if (currentConversation.value?.id === convId) {
              currentConversation.value.messages.push(assistantMsg);
            }
            streamingContent.value = "";
            streaming.value = false;

            // Update conversation in list
            const idx = conversations.value.findIndex((c) => c.id === convId);
            if (idx !== -1) {
              conversations.value[idx].message_count += 2;
              conversations.value[idx].updated_at = new Date().toISOString();
            }
          }
          if (data.error) {
            streaming.value = false;
            streamingContent.value = "";
          }
        }
      );
    } catch {
      streaming.value = false;
      streamingContent.value = "";
    }
  }

  async function saveMessageAsNote(messageId: number) {
    return await apiPost<Record<string, unknown>>(
      `/api/chat/messages/${messageId}/save-as-note`,
      {}
    );
  }

  async function summarizeAsNote(conversationId: number) {
    return await apiPost<Record<string, unknown>>(
      `/api/chat/conversations/${conversationId}/summarize`,
      {}
    );
  }

  async function fetchStatus() {
    try {
      const data = await apiGet<OllamaStatus>("/api/chat/status");
      ollamaStatus.value = data.ollama;
      modelStatus.value = data.model;
      defaultModel.value = data.default_model;
    } catch {
      ollamaStatus.value = "unavailable";
      modelStatus.value = "not_found";
    }
  }

  function startStatusPolling() {
    fetchStatus();
    stopStatusPolling();
    statusPollTimer = setInterval(fetchStatus, 30_000);
  }

  function stopStatusPolling() {
    if (statusPollTimer !== null) {
      clearInterval(statusPollTimer);
      statusPollTimer = null;
    }
  }

  async function fetchModels() {
    try {
      const data = await apiGet<{ models: OllamaModel[] }>("/api/chat/models");
      models.value = data.models;
    } catch {
      models.value = [];
    }
  }

  return {
    conversations,
    currentConversation,
    total,
    loading,
    streaming,
    streamingContent,
    models,
    ollamaStatus,
    modelStatus,
    defaultModel,
    chatReady,
    fetchConversations,
    createConversation,
    fetchConversation,
    deleteConversation,
    updateTitle,
    sendMessage,
    saveMessageAsNote,
    summarizeAsNote,
    fetchModels,
    fetchStatus,
    startStatusPolling,
    stopStatusPolling,
  };
});