/**
 * Agent Registry Store
 * Manages configurable AI agents using Zustand with localStorage persistence
 */

import { create } from 'zustand';
import { persist } from 'zustand/middleware';
import type { AgentConfig } from './types';
import { getActionsForRole } from './types';
import { isKnownTTSProviderId } from '@/lib/audio/constants';
import type { GeneratedAgentConfig } from '@/lib/types/stage';
import { USER_AVATAR } from '@/lib/types/roundtable';
import type { Participant, ParticipantRole } from '@/lib/types/roundtable';
import { useUserProfileStore } from '@/lib/store/user-profile';
import type { AgentInfo } from '@openmaic/generation';

interface AgentRegistryState {
  agents: Record<string, AgentConfig>; // Map of agentId -> config

  // Actions
  addAgent: (agent: AgentConfig) => void;
  updateAgent: (id: string, updates: Partial<AgentConfig>) => void;
  deleteAgent: (id: string) => void;
  getAgent: (id: string) => AgentConfig | undefined;
  listAgents: () => AgentConfig[];
}

// Action types available to agents
const WHITEBOARD_ACTIONS = [
  'wb_open',
  'wb_close',
  'wb_draw_text',
  'wb_draw_shape',
  'wb_draw_chart',
  'wb_draw_latex',
  'wb_draw_table',
  'wb_draw_line',
  'wb_draw_code',
  'wb_edit_code',
  'wb_clear',
  'wb_delete',
];

const SLIDE_ACTIONS = ['spotlight', 'laser', 'play_video'];

// Default agents - always available on both server and client
const DEFAULT_AGENTS: Record<string, AgentConfig> = {
  'default-1': {
    id: 'default-1',
    name: 'AI teacher',
    role: 'teacher',
    persona: `You are the lead teacher of this classroom. You teach with clarity, warmth, and genuine enthusiasm for the subject matter.

Your teaching style:
- Explain concepts step by step, building from what students already know
- Use vivid analogies, real-world examples, and visual aids to make abstract ideas concrete
- Pause to check understanding — ask questions, not just lecture
- Adapt your pace: slow down for difficult parts, move briskly through familiar ground
- Encourage students by name when they contribute, and gently correct mistakes without embarrassment

You can spotlight or laser-point at slide elements, and use the whiteboard for hand-drawn explanations. Use these actions naturally as part of your teaching flow. Never announce your actions; just teach.

Tone: Professional yet approachable. Patient. Encouraging. You genuinely care about whether students understand.`,
    avatar: '/avatars/teacher.png',
    color: '#3b82f6',
    allowedActions: [...SLIDE_ACTIONS, ...WHITEBOARD_ACTIONS],
    priority: 10,
    createdAt: new Date(),
    updatedAt: new Date(),
    isDefault: true,
  },
};

/**
 * Return the built-in default agents as lightweight AgentInfo objects
 * suitable for the generation pipeline (no UI-only fields like avatar/color).
 */
export function getDefaultAgents(): AgentInfo[] {
  return Object.values(DEFAULT_AGENTS).map((a) => ({
    id: a.id,
    name: a.name,
    role: a.role,
    persona: a.persona,
  }));
}

/**
 * Portable snapshot of the built-in roster for persisted/server-generated
 * classrooms. Unlike AgentInfo this keeps persona presentation and voice
 * fields, so frozen bundles do not depend on whatever defaults a future app
 * version happens to ship.
 */
export function getDefaultGeneratedAgentConfigs(
  agentIds?: readonly string[],
): GeneratedAgentConfig[] {
  const selected = agentIds
    ? agentIds.map((id) => DEFAULT_AGENTS[id]).filter((agent): agent is AgentConfig => !!agent)
    : Object.values(DEFAULT_AGENTS);
  return selected.map((agent) => ({
    id: agent.id,
    name: agent.name,
    role: agent.role,
    persona: agent.persona,
    avatar: agent.avatar,
    color: agent.color,
    priority: agent.priority,
    ...(agent.voiceConfig
      ? {
          voiceConfig: {
            providerId: agent.voiceConfig.providerId,
            voiceId: agent.voiceConfig.voiceId,
          },
        }
      : {}),
    ...(agent.voiceDesign ? { voiceDesign: agent.voiceDesign } : {}),
  }));
}

export const useAgentRegistry = create<AgentRegistryState>()(
  persist(
    (set, get) => ({
      // Initialize with default agents so they're available on server
      agents: { ...DEFAULT_AGENTS },

      addAgent: (agent) =>
        set((state) => ({
          agents: { ...state.agents, [agent.id]: agent },
        })),

      updateAgent: (id, updates) =>
        set((state) => ({
          agents: {
            ...state.agents,
            [id]: { ...state.agents[id], ...updates, updatedAt: new Date() },
          },
        })),

      deleteAgent: (id) =>
        set((state) => {
          const { [id]: _removed, ...rest } = state.agents;
          return { agents: rest };
        }),

      getAgent: (id) => get().agents[id],

      listAgents: () => Object.values(get().agents),
    }),
    {
      name: 'agent-registry-storage',
      version: 11, // Bumped: add voiceOverrides field to AgentConfig
      migrate: (persistedState: unknown) => persistedState,
      // Generated agents are single-sourced on the stage document and rebuilt
      // from it on every classroom load — keep them out of the localStorage
      // snapshot entirely. The merge filter below stays as defense in depth
      // for snapshots written before this partialize existed.
      partialize: (state) => ({
        agents: Object.fromEntries(
          Object.entries(state.agents).filter(([, agent]) => !agent.isGenerated),
        ),
      }),
      // Merge persisted state with default agents
      // Default agents always use code-defined values (not cached)
      // Custom agents use persisted values
      merge: (persistedState: unknown, currentState) => {
        const persisted = persistedState as Record<string, unknown> | undefined;
        const persistedAgents = (persisted?.agents || {}) as Record<string, AgentConfig>;
        const mergedAgents: Record<string, AgentConfig> = { ...DEFAULT_AGENTS };

        // Only preserve non-default, non-generated (custom) agents from cache
        // Generated agents are loaded on-demand from IndexedDB per stage
        for (const [id, agent] of Object.entries(persistedAgents)) {
          const agentConfig = agent as AgentConfig;
          if (!id.startsWith('default-') && !agentConfig.isGenerated) {
            mergedAgents[id] = agentConfig;
          }
        }

        return {
          ...currentState,
          agents: mergedAgents,
        };
      },
    },
  ),
);

/**
 * Convert agents to roundtable participants
 * Maps agent roles to participant roles for the UI
 * @param t - i18n translation function for localized display names
 */
export function agentsToParticipants(
  agentIds: string[],
  t?: (key: string) => string,
): Participant[] {
  const registry = useAgentRegistry.getState();
  const participants: Participant[] = [];
  let hasTeacher = false;

  // Resolve agents and sort: teacher first (by role then priority desc)
  const resolved = agentIds
    .map((id) => registry.getAgent(id))
    .filter((a): a is AgentConfig => a != null);
  resolved.sort((a, b) => {
    if (a.role === 'teacher' && b.role !== 'teacher') return -1;
    if (a.role !== 'teacher' && b.role === 'teacher') return 1;
    return (b.priority ?? 0) - (a.priority ?? 0);
  });

  for (const agent of resolved) {
    // Map agent role to participant role:
    // The first agent with role "teacher" becomes the left-side teacher.
    // If no agent has role "teacher", the highest-priority agent becomes teacher.
    let role: ParticipantRole = 'student';
    if (!hasTeacher) {
      role = 'teacher';
      hasTeacher = true;
    }

    // Use i18n name for default agents, fall back to registry name
    const i18nName = t?.(`settings.agentNames.${agent.id}`);
    const displayName =
      i18nName && i18nName !== `settings.agentNames.${agent.id}` ? i18nName : agent.name;

    participants.push({
      id: agent.id,
      name: displayName,
      role,
      avatar: agent.avatar,
      isOnline: true,
      isSpeaking: false,
    });
  }

  // Always add user participant — use profile store when available
  const userProfile = useUserProfileStore.getState();
  const userName = userProfile.nickname || t?.('common.you') || 'You';
  const userAvatar = userProfile.avatar || USER_AVATAR;

  participants.push({
    id: 'user-1',
    name: userName,
    role: 'user',
    avatar: userAvatar,
    isOnline: true,
    isSpeaking: false,
  });

  return participants;
}

/**
 * Replace the registry's generated agents with the given stage roster.
 *
 * In-memory registry side effect: the persisted source of truth for the
 * roster is `stage.generatedAgentConfigs` on the stage document, and callers
 * persist it through the document path — the registry's own localStorage
 * snapshot excludes generated agents (see the persist `partialize` above), so
 * nothing written here becomes durable.
 * Clears previously loaded generated agents first (even when the new roster is
 * empty) so a prior classroom's roster cannot leak into the current one.
 * The contract keeps `voiceConfig.providerId` an open string; a binding whose
 * provider is not registered in this app is dropped here (the agent keeps its
 * voiceDesign, and the TTS path falls back at call time).
 * Returns the applied agent IDs.
 */
export function applyGeneratedAgentsToRegistry(
  stageId: string,
  agents: ReadonlyArray<GeneratedAgentConfig>,
): string[] {
  const registry = useAgentRegistry.getState();
  for (const agent of registry.listAgents()) {
    if (agent.isGenerated) registry.deleteAgent(agent.id);
  }

  const now = Date.now();
  const ids: string[] = [];
  for (const agent of agents) {
    const { voiceConfig, ...rest } = agent;
    registry.addAgent({
      ...rest,
      allowedActions: getActionsForRole(agent.role),
      isDefault: false,
      isGenerated: true,
      boundStageId: stageId,
      createdAt: new Date(now),
      updatedAt: new Date(now),
      ...(voiceConfig && isKnownTTSProviderId(voiceConfig.providerId)
        ? {
            voiceConfig: {
              providerId: voiceConfig.providerId,
              voiceId: voiceConfig.voiceId,
            },
          }
        : {}),
    });
    ids.push(agent.id);
  }

  // Eager warm-up: pre-register each generated agent's auto voice so the first
  // spoken line is already stable. Same idempotent ensure as the TTS path;
  // fire-and-forget. Dynamic import keeps this client-only dep out of the
  // server-importable store module.
  if (ids.length > 0 && typeof window !== 'undefined') {
    void import('@/lib/audio/agent-voice')
      .then((m) => m.warmUpAgentVoices(registry.listAgents().filter((a) => a.isGenerated)))
      .catch(() => undefined);
  }

  return ids;
}