<template>
  <div>
    <!-- ── System AI Providers (Global) ───────────────────────────────────── -->
    <section class="bg-white rounded-xl border border-gray-200 overflow-hidden mb-6">
      <div class="px-6 py-4 border-b border-gray-200">
        <h2 class="text-sm font-semibold text-gray-900">System AI Providers (Global)</h2>
        <p class="text-xs text-gray-500 mt-0.5">
          These settings apply to all classification jobs. Per-user overrides below take precedence when set.
        </p>
      </div>

      <!-- Loading spinner -->
      <div v-if="loadingSystem" class="p-6 text-center">
        <div class="flex items-center justify-center gap-2 text-gray-400 text-sm">
          <span class="animate-spin rounded-full border-2 border-current border-t-transparent w-4 h-4"></span>
          Loading AI providers…
        </div>
      </div>

      <!-- System error banner -->
      <div v-if="systemError" class="mx-6 mt-4 px-4 py-3 bg-red-50 border border-red-200 rounded-lg text-sm text-red-700">
        {{ systemError }}
      </div>

      <!-- Provider accordion list -->
      <div v-if="!loadingSystem" class="divide-y divide-gray-100">
        <div
          v-for="prov in systemProviders"
          :key="prov.provider_id"
          :class="['transition-colors', prov.is_active ? 'border-l-4 border-l-green-500' : '']"
        >
          <!-- Accordion header -->
          <button
            class="w-full flex items-center justify-between px-6 py-3 text-left hover:bg-gray-50 transition-colors"
            @click="toggleProvider(prov.provider_id)"
          >
            <div class="flex items-center gap-3">
              <span class="text-sm font-medium text-gray-900 capitalize">{{ prov.provider_id }}</span>
              <span
                v-if="prov.is_active"
                class="bg-green-100 text-green-700 text-xs font-semibold px-2 py-0.5 rounded-full"
              >Active</span>
            </div>
            <svg
              :class="['w-4 h-4 text-gray-400 transition-transform', openProviderId === prov.provider_id ? 'rotate-180' : '']"
              fill="none" stroke="currentColor" viewBox="0 0 24 24"
            >
              <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7" />
            </svg>
          </button>

          <!-- Accordion body -->
          <div v-if="openProviderId === prov.provider_id" class="px-6 pb-5 pt-2 bg-gray-50 space-y-3">
            <!-- API Key -->
            <div>
              <label class="block text-xs font-medium text-gray-600 mb-1">API Key</label>
              <input
                v-model="formByProvider[prov.provider_id].api_key"
                type="password"
                :placeholder="prov.has_api_key ? '(unchanged)' : '(not set)'"
                autocomplete="off"
                class="block w-full rounded-lg px-3 py-2 text-sm border border-gray-300 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500 transition-colors"
              />
            </div>

            <!-- Base URL -->
            <div>
              <label class="block text-xs font-medium text-gray-600 mb-1">Base URL</label>
              <input
                v-model="formByProvider[prov.provider_id].base_url"
                type="text"
                :placeholder="providerDefaultBaseUrl(prov.provider_id) || '(default)'"
                class="block w-full rounded-lg px-3 py-2 text-sm border border-gray-300 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500 transition-colors"
              />
            </div>

            <!-- Model name — searchable dropdown populated from provider's /models endpoint -->
            <div>
              <label class="block text-xs font-medium text-gray-600 mb-1">Model Name</label>
              <SearchableModelSelect
                v-model="formByProvider[prov.provider_id].model_name"
                :provider-id="prov.provider_id"
                :placeholder="providerDefaultModel(prov.provider_id)"
              />
            </div>

            <!-- Context chars -->
            <div>
              <label class="block text-xs font-medium text-gray-600 mb-1">Context Characters</label>
              <input
                v-model.number="formByProvider[prov.provider_id].context_chars"
                type="number"
                :placeholder="String(providerDefaultContextChars(prov.provider_id))"
                min="1000"
                max="2000000"
                class="block w-full rounded-lg px-3 py-2 text-sm border border-gray-300 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500 transition-colors"
              />
            </div>

            <!-- Action buttons -->
            <div class="flex items-center gap-2 pt-1">
              <!-- Set Active -->
              <button
                @click="saveSystemProvider(prov.provider_id, { activate: true })"
                :disabled="savingProvider === prov.provider_id || prov.is_active"
                class="text-xs bg-green-600 text-white font-semibold px-3 py-1.5 rounded-lg hover:bg-green-700 disabled:opacity-50 transition-colors"
              >
                Set Active
              </button>

              <!-- Save -->
              <button
                @click="saveSystemProvider(prov.provider_id)"
                :disabled="savingProvider === prov.provider_id"
                class="text-xs bg-indigo-600 text-white font-semibold px-3 py-1.5 rounded-lg hover:bg-indigo-700 disabled:opacity-50 flex items-center gap-1 transition-colors"
              >
                <span v-if="savingProvider === prov.provider_id" class="animate-spin rounded-full border-2 border-current border-t-transparent w-3 h-3"></span>
                {{ savingProvider === prov.provider_id ? 'Saving…' : 'Save' }}
              </button>

              <!-- Test Connection -->
              <button
                @click="runTestConnection(prov.provider_id)"
                :disabled="testingProvider === prov.provider_id || savingProvider === prov.provider_id"
                class="text-xs border border-gray-300 text-gray-700 font-semibold px-3 py-1.5 rounded-lg hover:bg-gray-100 disabled:opacity-50 flex items-center gap-1.5 transition-colors"
              >
                <span
                  v-if="testingProvider === prov.provider_id"
                  class="animate-spin rounded-full border-2 border-current border-t-transparent w-3 h-3"
                ></span>
                {{ testingProvider === prov.provider_id ? 'Testing…' : 'Test Connection' }}
              </button>

              <!-- Test result badge -->
              <span
                v-if="testResults[prov.provider_id] === 'ok'"
                class="text-xs bg-green-100 text-green-700 font-semibold px-2 py-1 rounded-full"
              >OK</span>
              <span
                v-else-if="testResults[prov.provider_id] === 'failed'"
                class="text-xs bg-red-100 text-red-700 font-semibold px-2 py-1 rounded-full"
              >Failed</span>
            </div>
          </div>
        </div>
      </div>
    </section>

    <!-- ── Per-user AI provider assignment (existing — DO NOT MODIFY) ─────── -->

    <!-- Loading state -->
    <div v-if="loading" class="bg-white rounded-xl border border-gray-200 p-8 text-center">
      <div class="flex items-center justify-center gap-2 text-gray-400 text-sm">
        <span class="animate-spin rounded-full border-2 border-current border-t-transparent w-4 h-4"></span>
        Loading AI config…
      </div>
    </div>

    <!-- Empty state -->
    <div v-else-if="users.length === 0" class="bg-white rounded-xl border border-gray-200 p-12 text-center">
      <h3 class="text-sm font-semibold text-gray-900 mb-1">No users yet</h3>
      <p class="text-sm text-gray-500">Create the first user account to get started.</p>
    </div>

    <!-- AI config table -->
    <div v-else class="bg-white rounded-xl border border-gray-200 overflow-hidden divide-y divide-gray-200">
      <table class="w-full">
        <thead>
          <tr class="bg-gray-50 text-left">
            <th class="px-4 py-3 text-xs font-semibold text-gray-500 uppercase tracking-wider">Email</th>
            <th class="px-4 py-3 text-xs font-semibold text-gray-500 uppercase tracking-wider">AI Provider</th>
            <th class="px-4 py-3 text-xs font-semibold text-gray-500 uppercase tracking-wider">AI Model</th>
            <th class="px-4 py-3 text-xs font-semibold text-gray-500 uppercase tracking-wider">Actions</th>
          </tr>
        </thead>
        <tbody class="divide-y divide-gray-200">
          <tr v-for="user in users" :key="user.id" class="bg-white text-sm">
            <td class="px-4 py-3 text-gray-900">{{ user.email }}</td>
            <td class="px-4 py-3">
              <select
                v-model="configs[user.id].provider"
                class="block w-36 rounded-lg px-2 py-1.5 text-sm border border-gray-300 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500 transition-colors bg-white"
              >
                <option value="">— None —</option>
                <option v-for="p in providers" :key="p.value" :value="p.value">{{ p.label }}</option>
              </select>
            </td>
            <td class="px-4 py-3">
              <input
                v-model="configs[user.id].model"
                type="text"
                placeholder="e.g. gpt-4o"
                class="block w-40 rounded-lg px-2 py-1.5 text-sm border border-gray-300 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500 transition-colors"
              />
            </td>
            <td class="px-4 py-3">
              <div class="flex items-center gap-2">
                <button
                  @click="saveConfig(user.id)"
                  :disabled="savingId === user.id"
                  class="text-sm text-indigo-600 hover:text-indigo-700 font-semibold disabled:opacity-50 flex items-center gap-1"
                >
                  <span v-if="savingId === user.id" class="animate-spin rounded-full border-2 border-current border-t-transparent w-3 h-3"></span>
                  {{ savingId === user.id ? 'Saving…' : 'Save' }}
                </button>
                <span
                  v-if="savedId === user.id"
                  class="text-xs text-green-600 font-semibold"
                >
                  Saved
                </span>
              </div>
            </td>
          </tr>
        </tbody>
      </table>
    </div>

    <!-- Error message -->
    <p v-if="loadError" class="mt-3 text-sm text-red-600">{{ loadError }}</p>
  </div>
</template>

<script setup>
import { ref, reactive, onMounted } from 'vue'
import * as api from '../../api/client.js'
import { getAiConfig, saveAiConfig, testAiConnection } from '../../api/client.js'
import SearchableModelSelect from '../ui/SearchableModelSelect.vue'

// ── Per-provider default lookup (mirrors backend PROVIDER_DEFAULTS) ───────────

const _PROVIDER_DEFAULTS = {
  openai:     { base_url: null,                                                       model: 'gpt-4o',                           context_chars: 120000 },
  anthropic:  { base_url: null,                                                       model: 'claude-sonnet-4-6',                context_chars: 180000 },
  gemini:     { base_url: 'https://generativelanguage.googleapis.com/v1beta/openai/', model: 'gemini-2.0-flash',                 context_chars: 800000 },
  groq:       { base_url: 'https://api.groq.com/openai/v1',                          model: 'llama-3.3-70b-versatile',          context_chars: 128000 },
  xai:        { base_url: 'https://api.x.ai/v1',                                     model: 'grok-3-mini',                      context_chars: 128000 },
  deepseek:   { base_url: 'https://api.deepseek.com',                                model: 'deepseek-chat',                    context_chars: 60000  },
  openrouter: { base_url: 'https://openrouter.ai/api/v1',                             model: 'anthropic/claude-3.5-sonnet',      context_chars: 180000 },
  mistral:    { base_url: 'https://api.mistral.ai/v1',                               model: 'mistral-large-latest',             context_chars: 128000 },
  ollama:     { base_url: 'http://host.docker.internal:11434/v1',                    model: 'llama3.2',                         context_chars: 8000   },
  lmstudio:   { base_url: 'http://host.docker.internal:1234/v1',                     model: 'gemma-4-e4b-it',                   context_chars: 8000   },
}

function providerDefaultBaseUrl(pid) { return _PROVIDER_DEFAULTS[pid]?.base_url || '' }
function providerDefaultModel(pid)   { return _PROVIDER_DEFAULTS[pid]?.model || '' }
function providerDefaultContextChars(pid) { return _PROVIDER_DEFAULTS[pid]?.context_chars || 8000 }

// ── System provider state ─────────────────────────────────────────────────────

const systemProviders = ref([])
const loadingSystem = ref(false)
const systemError = ref(null)
const openProviderId = ref(null)
const formByProvider = reactive({})
const testResults = reactive({})
const savingProvider = ref(null)
const testingProvider = ref(null)

function toggleProvider(pid) {
  openProviderId.value = openProviderId.value === pid ? null : pid
}

function _initForm(prov) {
  formByProvider[prov.provider_id] = {
    api_key: '',             // write-only: never pre-filled from server
    base_url: prov.base_url || '',
    model_name: prov.model_name || '',
    context_chars: prov.context_chars || 0,
  }
}

async function loadSystemProviders() {
  loadingSystem.value = true
  systemError.value = null
  try {
    const data = await getAiConfig()
    systemProviders.value = data.providers || []
    for (const prov of systemProviders.value) {
      _initForm(prov)
    }
  } catch (e) {
    systemError.value = e.message || 'Failed to load AI provider config'
  } finally {
    loadingSystem.value = false
  }
}

async function saveSystemProvider(providerId, opts = {}) {
  savingProvider.value = providerId
  const form = formByProvider[providerId] || {}
  const body = { provider_id: providerId }

  // Only include fields the admin actually modified (api_key only if user typed something)
  if (form.api_key !== '') body.api_key = form.api_key
  if (form.base_url !== '') body.base_url = form.base_url
  if (form.model_name !== '') body.model_name = form.model_name
  if (form.context_chars && form.context_chars !== 0) body.context_chars = form.context_chars
  if (opts.activate) body.is_active = true

  try {
    await saveAiConfig(body)
    await loadSystemProviders()
  } catch (e) {
    systemError.value = e.message || 'Failed to save provider config'
  } finally {
    savingProvider.value = null
  }
}

async function runTestConnection(providerId) {
  testingProvider.value = providerId
  testResults[providerId] = null
  const form = formByProvider[providerId] || {}
  // Pass unsaved form values so admins can test credentials before saving
  const overrides = {}
  if (form.api_key)     overrides.api_key   = form.api_key
  if (form.base_url)    overrides.base_url   = form.base_url
  if (form.model_name)  overrides.model_name = form.model_name
  try {
    const r = await testAiConnection(providerId, overrides)
    testResults[providerId] = r.ok ? 'ok' : 'failed'
  } catch {
    testResults[providerId] = 'failed'
  } finally {
    testingProvider.value = null
  }
  setTimeout(() => { testResults[providerId] = null }, 3000)
}

// ── Per-user assignment state (existing — DO NOT MODIFY) ──────────────────────

const users = ref([])
const loading = ref(false)
const loadError = ref(null)
const savingId = ref(null)
const savedId = ref(null)

// Per-user config state: { [userId]: { provider, model } }
const configs = reactive({})

const providers = [
  { value: 'openai', label: 'OpenAI' },
  { value: 'anthropic', label: 'Anthropic' },
  { value: 'ollama', label: 'Ollama' },
  { value: 'lmstudio', label: 'LM Studio' },
]

async function saveConfig(userId) {
  savingId.value = userId
  savedId.value = null
  try {
    await api.adminUpdateAiConfig(
      userId,
      configs[userId].provider || null,
      configs[userId].model || null
    )
    savedId.value = userId
    setTimeout(() => {
      if (savedId.value === userId) savedId.value = null
    }, 1500)
  } catch (e) {
    loadError.value = e.message
  } finally {
    savingId.value = null
  }
}

onMounted(async () => {
  // Load system providers AND per-user list in parallel
  loadSystemProviders()

  loading.value = true
  loadError.value = null
  try {
    const data = await api.adminListUsers()
    users.value = data.items || []
    // Initialize per-user config state
    for (const user of users.value) {
      configs[user.id] = {
        provider: user.ai_provider || '',
        model: user.ai_model || '',
      }
    }
  } catch (e) {
    loadError.value = e.message
  } finally {
    loading.value = false
  }
})
</script>
