"use client";

import { createNotesApiClient } from "@/lib/api-helpers";
import type {
  PromptTemplate,
  RunPromptInput,
  RunPromptOutput,
  SimilarNote,
  KnowledgeGap,
} from "@/lib/types";

// ── Template CRUD ─────────────────────────────────────────────

export async function listPromptTemplates(): Promise<PromptTemplate[]> {
  const api = createNotesApiClient();
  const res = await api.fetch<{ items: PromptTemplate[] }>("/note-prompts");
  return res.items;
}

export async function getPromptTemplate(id: string): Promise<PromptTemplate> {
  const api = createNotesApiClient();
  return api.fetch<PromptTemplate>(`/note-prompts/${encodeURIComponent(id)}`);
}

export async function createPromptTemplate(
  input: Omit<PromptTemplate, "id" | "isBuiltin">,
): Promise<PromptTemplate> {
  const api = createNotesApiClient();
  return api.fetch<PromptTemplate>("/note-prompts", {
    method: "POST",
    body: JSON.stringify(input),
  });
}

export async function deletePromptTemplate(id: string): Promise<void> {
  const api = createNotesApiClient();
  await api.fetch(`/note-prompts/${encodeURIComponent(id)}`, { method: "DELETE" });
}

// ── Run prompts ───────────────────────────────────────────────

export async function runPrompt(input: RunPromptInput): Promise<RunPromptOutput> {
  const api = createNotesApiClient();
  return api.fetch<RunPromptOutput>("/note-prompts/run", {
    method: "POST",
    body: JSON.stringify(input),
  });
}

// ── Run prompts (streaming) ───────────────────────────────────

export async function runPromptStream(
  input: RunPromptInput,
  onToken: (content: string) => void,
  onDone: (meta: Partial<RunPromptOutput>) => void,
  onError?: (message: string) => void,
): Promise<void> {
  const api = createNotesApiClient();
  const baseUrl = (api as unknown as { baseUrl?: string }).baseUrl ?? "";
  const token = typeof window !== "undefined" ? localStorage.getItem("access_token") : null;
  const headers: Record<string, string> = { "Content-Type": "application/json" };
  if (token) headers["Authorization"] = `Bearer ${token}`;

  const res = await fetch(`${baseUrl}/note-prompts/run-stream`, {
    method: "POST",
    headers,
    body: JSON.stringify(input),
  });

  if (!res.ok || !res.body) {
    onError?.(res.statusText || "Stream failed");
    return;
  }

  const reader = res.body.getReader();
  const decoder = new TextDecoder();
  let buffer = "";

  while (true) {
    const { done, value } = await reader.read();
    if (done) break;
    buffer += decoder.decode(value, { stream: true });
    const lines = buffer.split("\n\n");
    buffer = lines.pop() ?? "";
    for (const line of lines) {
      if (!line.startsWith("data: ")) continue;
      try {
        const payload = JSON.parse(line.slice(6));
        if (payload.type === "token") onToken(payload.content);
        else if (payload.type === "done") onDone(payload);
        else if (payload.type === "error") onError?.(payload.message);
      } catch { /* skip malformed */ }
    }
  }
}

// ── History ──────────────────────────────────────────────────

export interface PromptHistoryItem {
  id: string;
  noteId: string;
  workspaceId: string;
  toolName?: string;
  state: string;
  reason?: string;
  afterSummary?: string;
  createdAt: string;
}

export async function listPromptHistory(
  workspaceId: string,
  limit = 20,
): Promise<{ items: PromptHistoryItem[]; total: number }> {
  const api = createNotesApiClient();
  return api.fetch(`/note-prompts/history?workspaceId=${encodeURIComponent(workspaceId)}&limit=${limit}`);
}

// ── Intelligence endpoints ────────────────────────────────────

export async function suggestTags(
  noteId: string,
  workspaceId: string,
): Promise<string[]> {
  const api = createNotesApiClient();
  const res = await api.fetch<{ tags: string[] }>(
    `/notes/${encodeURIComponent(noteId)}/suggest-tags`,
    { method: "POST", body: JSON.stringify({ workspaceId }) },
  );
  return res.tags;
}

export async function checkDuplicates(
  noteId: string,
  workspaceId: string,
  threshold = 0.85,
): Promise<SimilarNote[]> {
  const api = createNotesApiClient();
  const res = await api.fetch<{ duplicates: SimilarNote[] }>(
    `/notes/${encodeURIComponent(noteId)}/check-duplicates`,
    { method: "POST", body: JSON.stringify({ workspaceId, threshold }) },
  );
  return res.duplicates;
}

export async function suggestLinks(
  noteId: string,
  workspaceId: string,
  threshold = 0.6,
): Promise<SimilarNote[]> {
  const api = createNotesApiClient();
  const res = await api.fetch<{ suggestions: SimilarNote[] }>(
    `/notes/${encodeURIComponent(noteId)}/suggest-links`,
    { method: "POST", body: JSON.stringify({ workspaceId, threshold }) },
  );
  return res.suggestions;
}

export async function getReadingTime(
  noteId: string,
  workspaceId: string,
): Promise<{ wordCount: number; readingTimeMinutes: number }> {
  const api = createNotesApiClient();
  return api.fetch(`/notes/${encodeURIComponent(noteId)}/reading-time?workspaceId=${encodeURIComponent(workspaceId)}`);
}

export async function compareNotes(
  noteIds: string[],
  workspaceId: string,
): Promise<RunPromptOutput> {
  const api = createNotesApiClient();
  return api.fetch<RunPromptOutput>("/notes/compare", {
    method: "POST",
    body: JSON.stringify({ noteIds, workspaceId }),
  });
}

export async function mergeNotes(
  noteIds: string[],
  workspaceId: string,
): Promise<RunPromptOutput> {
  const api = createNotesApiClient();
  return api.fetch<RunPromptOutput>("/notes/merge", {
    method: "POST",
    body: JSON.stringify({ noteIds, workspaceId }),
  });
}

export async function getKnowledgeGaps(
  workspaceId: string,
): Promise<{ gaps: KnowledgeGap[]; topicMap: Record<string, number> }> {
  const api = createNotesApiClient();
  return api.fetch(`/workspaces/${encodeURIComponent(workspaceId)}/knowledge-gaps`, {
    method: "POST",
  });
}