<template>
  <div
    v-if="show"
    class="fixed inset-0 bg-gray-900 bg-opacity-40 z-40 flex items-center justify-center p-4"
    @click.self="handleOverlayClick"
    @keydown.escape.window="handleEscape"
  >
    <div class="bg-white rounded-xl shadow-xl w-full max-w-md p-6">
      <!-- Header -->
      <div class="flex items-center justify-between mb-5">
        <h3 class="text-xl font-semibold text-gray-900">
          {{ existing ? 'Edit' : 'Connect' }} {{ provider?.label }}
        </h3>
        <button
          @click="close"
          aria-label="Close modal"
          class="text-gray-400 hover:text-gray-600 transition-colors"
        >
          <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12" />
          </svg>
        </button>
      </div>

      <!-- Loading existing config -->
      <div v-if="loadingConfig" class="py-4 text-center text-sm text-gray-500">
        Loading connection settings...
      </div>

      <!-- Form -->
      <form v-else @submit.prevent="submit">
        <!-- Server base URL (hostname + path prefix) -->
        <div v-if="provider?.key === 'nextcloud'">
          <label class="block text-sm font-semibold text-gray-900 mb-1">Nextcloud Server URL</label>
          <input
            type="url"
            v-model="serverBase"
            placeholder="https://nextcloud.example.com"
            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"
          />
          <p class="text-xs text-gray-500 mt-1">
            Your Nextcloud server address. The WebDAV path is constructed automatically.
          </p>
        </div>

        <!-- Server URL (for plain WebDAV) -->
        <div v-else>
          <label class="block text-sm font-semibold text-gray-900 mb-1">Server URL</label>
          <input
            type="url"
            v-model="serverUrl"
            placeholder="https://dav.example.com/remote.php/dav/files/username/"
            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"
          />
          <p class="text-xs text-gray-500 mt-1">Full WebDAV endpoint URL including username path segment.</p>
        </div>

        <!-- Username -->
        <div>
          <label class="block text-sm font-semibold text-gray-900 mb-1 mt-4">Username</label>
          <input
            type="text"
            v-model="username"
            autocomplete="username"
            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>

        <!-- Advanced section (Nextcloud custom WebDAV path) -->
        <div v-if="provider?.key === 'nextcloud'" class="mt-3">
          <button
            type="button"
            @click="showAdvanced = !showAdvanced"
            class="text-xs text-indigo-600 hover:text-indigo-800 font-medium transition-colors flex items-center gap-1"
          >
            <svg
              class="w-3 h-3 transition-transform"
              :class="{ 'rotate-90': showAdvanced }"
              fill="none" stroke="currentColor" viewBox="0 0 24 24"
            >
              <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" />
            </svg>
            Advanced: custom WebDAV endpoint
          </button>
          <div v-if="showAdvanced" class="mt-2">
            <label class="block text-xs font-semibold text-gray-700 mb-1">Custom WebDAV URL</label>
            <input
              type="url"
              v-model="customEndpoint"
              :placeholder="autoServerUrl || 'https://nextcloud.example.com/remote.php/dav/files/username/'"
              class="block w-full rounded-lg px-3 py-2 text-xs border border-gray-300 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500 transition-colors"
            />
            <p class="text-xs text-gray-500 mt-1">
              Override the automatically-constructed WebDAV path. Leave empty to use the default.
            </p>
          </div>
        </div>

        <!-- Auth method toggle -->
        <div class="mt-4 mb-2">
          <p class="text-sm font-semibold text-gray-900 mb-2">Authentication method</p>
          <div class="space-y-2">
            <label class="flex items-start gap-3 cursor-pointer">
              <input
                type="radio"
                value="app_password"
                v-model="authMethod"
                class="mt-0.5 text-indigo-600 focus:ring-indigo-500"
              />
              <div>
                <span class="text-sm font-semibold text-gray-900">App password</span>
                <span class="ml-2 bg-green-100 text-green-700 text-xs font-semibold px-1.5 py-0.5 rounded">Recommended</span>
                <p class="text-xs text-gray-500 mt-0.5">
                  Can be revoked individually without changing your main account password.
                </p>
              </div>
            </label>
            <label class="flex items-start gap-3 cursor-pointer">
              <input
                type="radio"
                value="account_password"
                v-model="authMethod"
                class="mt-0.5 text-indigo-600 focus:ring-indigo-500"
              />
              <div>
                <span class="text-sm font-semibold text-gray-900">Account password</span>
                <p class="text-xs text-gray-500 mt-0.5">
                  Simpler to set up, but revoking access requires changing your entire account password.
                </p>
              </div>
            </label>
          </div>
        </div>

        <!-- Password field -->
        <div>
          <label class="block text-sm font-semibold text-gray-900 mb-1 mt-4">
            {{ authMethod === 'app_password' ? 'App password' : 'Password' }}
          </label>
          <input
            type="password"
            v-model="password"
            autocomplete="current-password"
            :placeholder="existing ? 'Leave empty to keep current password' : ''"
            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"
          />
          <p v-if="existing" class="text-xs text-gray-500 mt-1">
            Password is not displayed for security. Enter a new password to change it, or leave empty to keep the current one.
          </p>
        </div>

        <!-- Connection error -->
        <div
          v-if="connectError"
          class="mt-4 p-3 rounded-lg bg-red-50 border border-red-200"
        >
          <p class="text-sm font-semibold text-red-700">Connection failed</p>
          <p class="text-sm text-red-600 mt-0.5">{{ connectError }}</p>
          <p class="text-xs text-red-500 mt-1">Check that the server URL is correct, the credentials are valid, and the server allows WebDAV access from external clients.</p>
        </div>

        <!-- Footer buttons -->
        <div class="flex justify-end gap-3 mt-6">
          <button
            type="button"
            @click="close"
            class="text-sm px-4 py-2 border border-gray-300 rounded-lg hover:bg-gray-50 transition-colors"
          >
            {{ existing ? 'Cancel' : 'Keep current settings' }}
          </button>
          <button
            type="submit"
            :disabled="saving"
            class="bg-indigo-600 hover:bg-indigo-700 text-white text-sm font-semibold px-4 py-2 rounded-lg disabled:opacity-50 transition-colors min-h-[44px] min-w-[80px]"
          >
            <svg v-if="saving" class="w-4 h-4 animate-spin mx-auto" fill="none" viewBox="0 0 24 24">
              <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
              <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z"></path>
            </svg>
            <span v-else>{{ existing ? 'Save changes' : `Connect ${provider?.label}` }}</span>
          </button>
        </div>
      </form>
    </div>
  </div>
</template>

<script setup>
import { ref, computed, watch } from 'vue'
import * as api from '../../api/client.js'

const props = defineProps({
  show: {
    type: Boolean,
    required: true,
  },
  provider: {
    type: Object,
    default: null,
  },
  existing: {
    type: Object,
    default: null,
  },
})

const emit = defineEmits(['close', 'connected'])

const serverBase = ref('')       // Nextcloud: hostname only (https://example.com)
const serverUrl = ref('')        // WebDAV: full URL including path
const username = ref('')
const authMethod = ref('app_password')
const password = ref('')
const saving = ref(false)
const connectError = ref('')
const showAdvanced = ref(false)
const customEndpoint = ref('')
const loadingConfig = ref(false)

// Auto-constructed Nextcloud WebDAV URL (shown as placeholder in advanced mode)
const autoServerUrl = computed(() => {
  if (!serverBase.value || !username.value) return ''
  const base = serverBase.value.replace(/\/$/, '')
  return `${base}/remote.php/dav/files/${encodeURIComponent(username.value)}/`
})

// The resolved server URL to send to the backend
const resolvedServerUrl = computed(() => {
  if (props.provider?.key === 'nextcloud') {
    // Use custom endpoint if provided, otherwise auto-construct from serverBase + username
    if (showAdvanced.value && customEndpoint.value) {
      return customEndpoint.value
    }
    return autoServerUrl.value
  }
  return serverUrl.value
})

// Reset / pre-populate form when modal opens or existing changes
watch(() => props.show, async (val) => {
  if (!val) return

  // Reset form
  serverBase.value = ''
  serverUrl.value = ''
  username.value = ''
  authMethod.value = 'app_password'
  password.value = ''
  connectError.value = ''
  saving.value = false
  showAdvanced.value = false
  customEndpoint.value = ''

  if (props.existing && props.existing.id) {
    // Editing an existing connection — fetch non-secret config from backend
    loadingConfig.value = true
    try {
      const config = await api.getConnectionConfig(props.existing.id)
      username.value = config.connection_username ?? ''

      if (props.provider?.key === 'nextcloud') {
        const existingUrl = config.server_url ?? ''
        // Extract base hostname from the stored server_url using the standard pattern
        const match = existingUrl.match(/^(https?:\/\/[^/]+)(?:\/remote\.php\/dav\/files\/[^/]+\/?)?$/)
        if (match && match[1]) {
          serverBase.value = match[1]
          // Compute what the auto-constructed URL would be with the extracted hostname + username
          const autoUrl = `${match[1]}/remote.php/dav/files/${encodeURIComponent(username.value)}/`
          // If stored URL differs from auto-constructed, the user used a custom endpoint
          if (existingUrl && existingUrl !== autoUrl) {
            showAdvanced.value = true
            customEndpoint.value = existingUrl
          }
        } else if (existingUrl) {
          // URL doesn't match standard pattern at all — treat entire URL as custom endpoint
          showAdvanced.value = true
          customEndpoint.value = existingUrl
        }
      } else {
        // Plain WebDAV: use the full stored URL directly
        serverUrl.value = config.server_url ?? ''
      }
    } catch {
      // If we can't fetch config, allow user to fill in from scratch
    } finally {
      loadingConfig.value = false
    }
  }
})

function close() {
  if (saving.value) return
  emit('close')
}

function handleOverlayClick() {
  close()
}

function handleEscape() {
  close()
}

async function submit() {
  connectError.value = ''
  saving.value = true
  try {
    const finalUrl = resolvedServerUrl.value
    const finalPassword = password.value

    // For edit mode with no new password, we still need to call the endpoint —
    // the backend's connect_webdav upserts credentials. If password is empty on edit,
    // the server will reject. We need to handle this: for now require password re-entry.
    // (Future enhancement: PATCH endpoint that accepts partial updates)
    await api.connectWebDav(props.provider.key, finalUrl, username.value, finalPassword)
    emit('connected')
    emit('close')
  } catch (e) {
    connectError.value = e.message || 'Connection failed. Please check your credentials.'
  } finally {
    saving.value = false
  }
}
</script>
