import { Head, router, usePage } from '@inertiajs/react'
import { useRef, useState } from 'react'
import StyledTable from '~/components/StyledTable'
import SettingsLayout from '~/layouts/SettingsLayout'
import { NomadOllamaModel } from '../../../types/ollama'
import StyledButton from '~/components/StyledButton'
import useServiceInstalledStatus from '~/hooks/useServiceInstalledStatus'
import Alert from '~/components/Alert'
import { useNotifications } from '~/context/NotificationContext'
import api from '~/lib/api'
import { useModals } from '~/context/ModalContext'
import StyledModal from '~/components/StyledModal'
import type { NomadInstalledModel } from '../../../types/ollama'
import { SERVICE_NAMES } from '../../../constants/service_names'
import Switch from '~/components/inputs/Switch'
import StyledSectionHeader from '~/components/StyledSectionHeader'
import { useMutation, useQuery } from '@tanstack/react-query'
import Input from '~/components/inputs/Input'
import { IconSearch, IconRefresh } from '@tabler/icons-react'
import useDebounce from '~/hooks/useDebounce'
import ActiveModelDownloads from '~/components/ActiveModelDownloads'
import { useSystemInfo } from '~/hooks/useSystemInfo'

export default function ModelsPage(props: {
  models: {
    availableModels: NomadOllamaModel[]
    installedModels: NomadInstalledModel[]
    settings: { chatSuggestionsEnabled: boolean; aiAssistantCustomName: string; remoteOllamaUrl: string }
  }
}) {
  const { aiAssistantName } = usePage<{ aiAssistantName: string }>().props
  const { isInstalled } = useServiceInstalledStatus(SERVICE_NAMES.OLLAMA)
  const { addNotification } = useNotifications()
  const { openModal, closeAllModals } = useModals()
  const { debounce } = useDebounce()
  const { data: systemInfo } = useSystemInfo({})

  const [gpuBannerDismissed, setGpuBannerDismissed] = useState(() => {
    try {
      return localStorage.getItem('nomad:gpu-banner-dismissed') === 'true'
    } catch {
      return false
    }
  })
  const [reinstalling, setReinstalling] = useState(false)

  const handleDismissGpuBanner = () => {
    setGpuBannerDismissed(true)
    try {
      localStorage.setItem('nomad:gpu-banner-dismissed', 'true')
    } catch {}
  }

  const handleForceReinstallOllama = () => {
    openModal(
      <StyledModal
        title="Reinstall AI Assistant?"
        onConfirm={async () => {
          closeAllModals()
          setReinstalling(true)
          try {
            const response = await api.forceReinstallService('nomad_ollama')
            if (!response || !response.success) {
              throw new Error(response?.message || 'Force reinstall failed')
            }
            addNotification({
              message: `${aiAssistantName} is being reinstalled with GPU support. This page will reload shortly.`,
              type: 'success',
            })
            try { localStorage.removeItem('nomad:gpu-banner-dismissed') } catch {}
            setTimeout(() => window.location.reload(), 5000)
          } catch (error) {
            addNotification({
              message: `Failed to reinstall: ${error instanceof Error ? error.message : 'Unknown error'}`,
              type: 'error',
            })
            setReinstalling(false)
          }
        }}
        onCancel={closeAllModals}
        open={true}
        confirmText="Reinstall"
        cancelText="Cancel"
      >
        <p className="text-text-primary">
          This will recreate the {aiAssistantName} container with GPU support enabled.
          Your downloaded models will be preserved. The service will be briefly
          unavailable during reinstall.
        </p>
      </StyledModal>,
      'gpu-health-force-reinstall-modal'
    )
  }
  const [chatSuggestionsEnabled, setChatSuggestionsEnabled] = useState(
    props.models.settings.chatSuggestionsEnabled
  )
  const [aiAssistantCustomName, setAiAssistantCustomName] = useState(
    props.models.settings.aiAssistantCustomName
  )
  const [remoteOllamaUrl, setRemoteOllamaUrl] = useState(props.models.settings.remoteOllamaUrl)
  const [remoteOllamaError, setRemoteOllamaError] = useState<string | null>(null)
  const [remoteOllamaSaving, setRemoteOllamaSaving] = useState(false)

  async function handleSaveRemoteOllama() {
    setRemoteOllamaError(null)
    setRemoteOllamaSaving(true)
    try {
      const res = await api.configureRemoteOllama(remoteOllamaUrl || null)
      if (res?.success) {
        addNotification({ message: res.message, type: 'success' })
        router.reload()
      }
    } catch (error: any) {
      const msg = error?.response?.data?.message || error?.message || 'Failed to configure remote Ollama.'
      setRemoteOllamaError(msg)
    } finally {
      setRemoteOllamaSaving(false)
    }
  }

  async function handleClearRemoteOllama() {
    setRemoteOllamaError(null)
    setRemoteOllamaSaving(true)
    try {
      const res = await api.configureRemoteOllama(null)
      if (res?.success) {
        setRemoteOllamaUrl('')
        addNotification({ message: 'Remote Ollama configuration cleared.', type: 'success' })
        router.reload()
      }
    } catch (error: any) {
      setRemoteOllamaError(error?.message || 'Failed to clear remote Ollama.')
    } finally {
      setRemoteOllamaSaving(false)
    }
  }

  const [query, setQuery] = useState('')
  const [queryUI, setQueryUI] = useState('')
  const [limit, setLimit] = useState(15)

  const debouncedSetQuery = debounce((val: string) => {
    setQuery(val)
  }, 300)

  const forceRefreshRef = useRef(false)
  const [isForceRefreshing, setIsForceRefreshing] = useState(false)

  const { data: availableModelData, isFetching, refetch } = useQuery({
    queryKey: ['ollama', 'availableModels', query, limit],
    queryFn: async () => {
      const force = forceRefreshRef.current
      forceRefreshRef.current = false
      const res = await api.getAvailableModels({
        query,
        recommendedOnly: false,
        limit,
        force: force || undefined,
      })
      if (!res) {
        return {
          models: [],
          hasMore: false,
        }
      }
      return res
    },
    initialData: { models: props.models.availableModels, hasMore: false },
  })

  async function handleForceRefresh() {
    forceRefreshRef.current = true
    setIsForceRefreshing(true)
    await refetch()
    setIsForceRefreshing(false)
    addNotification({ message: 'Model list refreshed from remote.', type: 'success' })
  }

  async function handleInstallModel(modelName: string) {
    try {
      const res = await api.downloadModel(modelName)
      if (res.success) {
        addNotification({
          message: `Model download initiated for ${modelName}. It may take some time to complete.`,
          type: 'success',
        })
      }
    } catch (error) {
      console.error('Error installing model:', error)
      addNotification({
        message: `There was an error installing the model: ${modelName}. Please try again.`,
        type: 'error',
      })
    }
  }

  async function handleDeleteModel(modelName: string) {
    try {
      const res = await api.deleteModel(modelName)
      if (res.success) {
        addNotification({
          message: `Model deleted: ${modelName}.`,
          type: 'success',
        })
      }
      closeAllModals()
      router.reload()
    } catch (error) {
      console.error('Error deleting model:', error)
      addNotification({
        message: `There was an error deleting the model: ${modelName}. Please try again.`,
        type: 'error',
      })
    }
  }

  async function confirmDeleteModel(model: string) {
    openModal(
      <StyledModal
        title="Delete Model?"
        onConfirm={() => {
          handleDeleteModel(model)
        }}
        onCancel={closeAllModals}
        open={true}
        confirmText="Delete"
        cancelText="Cancel"
        confirmVariant="primary"
      >
        <p className="text-text-primary">
          Are you sure you want to delete this model? You will need to download it again if you want
          to use it in the future.
        </p>
      </StyledModal>,
      'confirm-delete-model-modal'
    )
  }

  const updateSettingMutation = useMutation({
    mutationFn: async ({ key, value }: { key: string; value: boolean | string }) => {
      return await api.updateSetting(key, value)
    },
    onSuccess: () => {
      addNotification({
        message: 'Setting updated successfully.',
        type: 'success',
      })
    },
    onError: (error) => {
      console.error('Error updating setting:', error)
      addNotification({
        message: 'There was an error updating the setting. Please try again.',
        type: 'error',
      })
    },
  })

  return (
    <SettingsLayout>
      <Head title={`${aiAssistantName} Settings | Project N.O.M.A.D.`} />
      <div className="xl:pl-72 w-full">
        <main className="px-12 py-6">
          <h1 className="text-4xl font-semibold mb-4">{aiAssistantName}</h1>
          <p className="text-text-muted mb-4">
            Easily manage the {aiAssistantName}'s settings and installed models. We recommend
            starting with smaller models first to see how they perform on your system before moving
            on to larger ones.
          </p>
          {!isInstalled && (
            <Alert
              title={`${aiAssistantName}'s dependencies are not installed. Please install them to manage AI models.`}
              type="warning"
              variant="solid"
              className="!mt-6"
            />
          )}
          {isInstalled && systemInfo?.gpuHealth?.status === 'passthrough_failed' && !gpuBannerDismissed && (
            <Alert
              type="warning"
              variant="bordered"
              title="GPU Not Accessible"
              message={`Your system has an NVIDIA GPU, but ${aiAssistantName} can't access it. AI is running on CPU only, which is significantly slower.`}
              className="!mt-6"
              dismissible={true}
              onDismiss={handleDismissGpuBanner}
              buttonProps={{
                children: `Fix: Reinstall ${aiAssistantName}`,
                icon: 'IconRefresh',
                variant: 'action',
                size: 'sm',
                onClick: handleForceReinstallOllama,
                loading: reinstalling,
                disabled: reinstalling,
              }}
            />
          )}

          <StyledSectionHeader title="Settings" className="mt-8 mb-4" />
          <div className="bg-surface-primary rounded-lg border-2 border-border-subtle p-6">
            <div className="space-y-4">
              <Switch
                checked={chatSuggestionsEnabled}
                onChange={(newVal) => {
                  setChatSuggestionsEnabled(newVal)
                  updateSettingMutation.mutate({ key: 'chat.suggestionsEnabled', value: newVal })
                }}
                label="Chat Suggestions"
                description="Display AI-generated conversation starters in the chat interface"
              />
              <Input
                name="aiAssistantCustomName"
                label="Assistant Name"
                helpText='Give your AI assistant a custom name that will be used in the chat interface and other areas of the application.'
                placeholder="AI Assistant"
                value={aiAssistantCustomName}
                onChange={(e) => setAiAssistantCustomName(e.target.value)}
                onBlur={() =>
                  updateSettingMutation.mutate({
                    key: 'ai.assistantCustomName',
                    value: aiAssistantCustomName,
                  })
                }
              />
            </div>
          </div>
          <StyledSectionHeader title="Remote Connection" className="mt-8 mb-4" />
          <div className="bg-white rounded-lg border-2 border-gray-200 p-6">
            <p className="text-sm text-gray-500 mb-4">
              Connect to any OpenAI-compatible API server — Ollama, LM Studio, llama.cpp, and others are all supported.
              For remote Ollama instances, the host must be started with <code className="bg-gray-100 px-1 rounded">OLLAMA_HOST=0.0.0.0</code>.
            </p>
            {props.models.settings.remoteOllamaUrl && (
              <p className="text-sm text-green-700 bg-green-50 border border-green-200 rounded px-3 py-2 mb-4">
                Currently configured: <span className="font-mono">{props.models.settings.remoteOllamaUrl}</span>
              </p>
            )}
            <div className="flex items-end gap-3">
              <div className="flex-1">
                <Input
                  name="remoteOllamaUrl"
                  label="Remote Ollama/OpenAI API URL"
                  placeholder="http://192.168.1.100:11434  (or :1234 for OpenAI API Compatible Apps)"
                  value={remoteOllamaUrl}
                  onChange={(e) => {
                    setRemoteOllamaUrl(e.target.value)
                    setRemoteOllamaError(null)
                  }}
                />
                {remoteOllamaError && (
                  <p className="text-sm text-red-600 mt-1">{remoteOllamaError}</p>
                )}
              </div>
              <StyledButton
                variant="primary"
                onClick={handleSaveRemoteOllama}
                loading={remoteOllamaSaving}
                disabled={remoteOllamaSaving || !remoteOllamaUrl}
                className="mb-0.5"
              >
                Save &amp; Test
              </StyledButton>
              {props.models.settings.remoteOllamaUrl && (
                <StyledButton
                  variant="danger"
                  onClick={handleClearRemoteOllama}
                  loading={remoteOllamaSaving}
                  disabled={remoteOllamaSaving}
                  className="mb-0.5"
                >
                  Clear
                </StyledButton>
              )}
            </div>
          </div>

          <ActiveModelDownloads withHeader />

          <StyledSectionHeader title="Models" className="mt-12 mb-4" />
          <p className="text-sm text-desert-stone mb-4">
            Model downloading is only supported when using an Ollama backend. If you are connected to an OpenAI API host (e.g. LM Studio), you will need to download models directly in that application.
          </p>
          <div className="flex justify-start items-center gap-3 mt-4">
            <Input
              name="search"
              label=""
              placeholder="Search language models.."
              value={queryUI}
              onChange={(e) => {
                setQueryUI(e.target.value)
                debouncedSetQuery(e.target.value)
              }}
              className="w-1/3"
              leftIcon={<IconSearch className="w-5 h-5 text-text-muted" />}
            />
            <StyledButton
              variant="secondary"
              onClick={handleForceRefresh}
              icon="IconRefresh"
              loading={isForceRefreshing}
              className='mt-1'
            >
              Refresh Models
            </StyledButton>
          </div>
          <StyledTable<NomadOllamaModel>
            className="font-semibold mt-4"
            rowLines={true}
            columns={[
              {
                accessor: 'name',
                title: 'Name',
                render(record) {
                  return (
                    <div className="flex flex-col">
                      <p className="text-lg font-semibold">{record.name}</p>
                      <p className="text-sm text-text-muted">{record.description}</p>
                    </div>
                  )
                },
              },
              {
                accessor: 'estimated_pulls',
                title: 'Estimated Pulls',
              },
              {
                accessor: 'model_last_updated',
                title: 'Last Updated',
              },
            ]}
            data={availableModelData?.models || []}
            loading={isFetching}
            expandable={{
              expandedRowRender: (record) => (
                <div className="pl-14">
                  <div className="bg-surface-primary overflow-hidden">
                    <table className="min-w-full divide-y divide-border-subtle">
                      <thead className="bg-surface-primary">
                        <tr>
                          <th className="px-6 py-3 text-left text-xs font-medium text-text-muted uppercase tracking-wider">
                            Tag
                          </th>
                          <th className="px-6 py-3 text-left text-xs font-medium text-text-muted uppercase tracking-wider">
                            Input Type
                          </th>
                          <th className="px-6 py-3 text-left text-xs font-medium text-text-muted uppercase tracking-wider">
                            Context Size
                          </th>
                          <th className="px-6 py-3 text-left text-xs font-medium text-text-muted uppercase tracking-wider">
                            Model Size
                          </th>
                          <th className="px-6 py-3 text-left text-xs font-medium text-text-muted uppercase tracking-wider">
                            Action
                          </th>
                        </tr>
                      </thead>
                      <tbody className="bg-surface-primary divide-y divide-border-subtle">
                        {record.tags.map((tag, tagIndex) => {
                          const isInstalled = props.models.installedModels.some(
                            (mod) => mod.name === tag.name
                          )
                          return (
                            <tr key={tagIndex} className="hover:bg-surface-secondary">
                              <td className="px-6 py-4 whitespace-nowrap">
                                <span className="text-sm font-medium text-text-primary">
                                  {tag.name}
                                </span>
                              </td>
                              <td className="px-6 py-4 whitespace-nowrap">
                                <span className="text-sm text-text-secondary">{tag.input || 'N/A'}</span>
                              </td>
                              <td className="px-6 py-4 whitespace-nowrap">
                                <span className="text-sm text-text-secondary">
                                  {tag.context || 'N/A'}
                                </span>
                              </td>
                              <td className="px-6 py-4 whitespace-nowrap">
                                <span className="text-sm text-text-secondary">{tag.size || 'N/A'}</span>
                              </td>
                              <td className="px-6 py-4 whitespace-nowrap">
                                <StyledButton
                                  variant={isInstalled ? 'danger' : 'primary'}
                                  onClick={() => {
                                    if (!isInstalled) {
                                      handleInstallModel(tag.name)
                                    } else {
                                      confirmDeleteModel(tag.name)
                                    }
                                  }}
                                  icon={isInstalled ? 'IconTrash' : 'IconDownload'}
                                >
                                  {isInstalled ? 'Delete' : 'Install'}
                                </StyledButton>
                              </td>
                            </tr>
                          )
                        })}
                      </tbody>
                    </table>
                  </div>
                </div>
              ),
            }}
          />
          <div className="flex justify-center mt-6">
            {availableModelData?.hasMore && (
              <StyledButton
                variant="primary"
                onClick={() => {
                  setLimit((prev) => prev + 15)
                }}
              >
                Load More
              </StyledButton>
            )}
          </div>
        </main>
      </div>
    </SettingsLayout>
  )
}