'use client';

import * as React from 'react';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { Database, Loader2, Play, Save } from 'lucide-react';
import { toast } from 'sonner';

import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import {
  Card,
  CardContent,
  CardDescription,
  CardFooter,
  CardHeader,
  CardTitle,
} from '@/components/ui/card';
import {
  Field,
  FieldDescription,
  FieldGroup,
  FieldLabel,
} from '@/components/ui/field';
import { Input } from '@/components/ui/input';
import { Progress } from '@/components/ui/progress';
import {
  Select,
  SelectContent,
  SelectGroup,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select';
import { Switch } from '@/components/ui/switch';
import services from '@/lib/services';
import type {
  ObjectStorageConfig,
  StorageConfig,
  StorageDriver,
  TaskExecution,
  TaskExecutionStatus,
} from '@/lib/services/admin/types';

const storageConfigKey = 'storage_config';
const storageMigrationTaskType = 'storage_migration';

const driverLabels: Record<StorageDriver, string> = {
  local: '本地文件系统',
  s3: 'AWS S3',
  r2: 'Cloudflare R2',
  minio: 'MinIO',
  oss: '阿里云 OSS',
  webdav: 'WebDAV',
};

const emptyObjectConfig: ObjectStorageConfig = {
  endpoint: '',
  region: '',
  bucket: '',
  access_key_id: '',
  secret_access_key: '',
  path_style: false,
  key_prefix: '',
  cdn_url: '',
};

function normalizeConfig(config: StorageConfig): StorageConfig {
  const s3 = { ...emptyObjectConfig, ...config.s3 };
  const r2 = { ...emptyObjectConfig, ...config.r2 };
  const minio = { ...emptyObjectConfig, ...config.minio };
  const oss = { ...emptyObjectConfig, ...config.oss };
  const webdav = { ...config.webdav };
  return {
    ...config,
    local: { root: config.local?.root || '.' },
    s3: { ...s3, region: s3.region || 'us-east-1' },
    r2: { ...r2, region: r2.region || 'auto' },
    minio: {
      ...minio,
      region: minio.region || 'us-east-1',
      path_style: config.minio?.path_style ?? true,
    },
    oss,
    webdav: {
      endpoint: webdav.endpoint || '',
      username: webdav.username || '',
      password: webdav.password || '',
      base_path: webdav.base_path || '',
    },
  };
}

type StorageMigrationView = {
  state: 'idle' | TaskExecutionStatus;
  id?: string;
  task_id?: string;
  source_driver?: StorageDriver;
  target_driver?: StorageDriver;
  error?: string;
};

type StorageMigrationPayload = {
  target: StorageConfig;
};

function parseMigrationPayload(payload: string): StorageConfig | undefined {
  try {
    const parsed = JSON.parse(payload) as Partial<StorageMigrationPayload>;
    return parsed.target ? normalizeConfig(parsed.target) : undefined;
  } catch {
    return undefined;
  }
}

function driverLabel(driver?: StorageDriver): string {
  return driver ? driverLabels[driver] : '未知';
}

function latestMigration(
  executions: TaskExecution[],
  current?: StorageConfig,
): StorageMigrationView {
  const execution = executions[0];
  if (!execution || execution.status === 'succeeded') {
    return { state: 'idle' };
  }
  const target = parseMigrationPayload(execution.payload);
  return {
    state: execution.status,
    id: execution.id,
    task_id: execution.task_id,
    source_driver: current?.driver,
    target_driver: target?.driver,
    error: execution.error_message,
  };
}

export function StorageConfigTab() {
  const queryClient = useQueryClient();
  const [config, setConfig] = React.useState<StorageConfig | null>(null);
  const query = useQuery({
    queryKey: ['admin', 'storage-config'],
    queryFn: async () => {
      const [configRecord, executions] = await Promise.all([
        services.adminSystemConfig.getSystemConfig(storageConfigKey),
        services.adminTask.listTaskExecutions({
          task_type: storageMigrationTaskType,
          page: 1,
          page_size: 1,
        }),
      ]);
      const current = normalizeConfig(
        JSON.parse(configRecord.value) as StorageConfig,
      );
      const migration = latestMigration(executions.items, current);
      return {
        config: current,
        migration,
      };
    },
    refetchInterval: (result) => {
      const state = result.state.data?.migration.state;
      return state === 'pending' || state === 'running' ? 2000 : false;
    },
  });

  React.useEffect(() => {
    if (query.data?.config) {
      setConfig((current) => {
        const normalized = normalizeConfig(query.data.config);
        if (current) {
          return {
            ...normalized,
            driver: current.driver,
          };
        }
        return normalized;
      });
    }
  }, [query.data?.config]);

  const saveMutation = useMutation({
    mutationFn: async (value: StorageConfig) => {
      await services.adminSystemConfig.updateSystemConfig(storageConfigKey, {
        value: JSON.stringify(value),
      });
    },
    onSuccess: () => {
      toast.success('存储配置已保存');
      void queryClient.invalidateQueries({
        queryKey: ['admin', 'storage-config'],
      });
    },
    onError: (error: Error) => {
      toast.error(error.message || '保存存储配置失败');
      void queryClient.invalidateQueries({
        queryKey: ['admin', 'storage-config'],
      });
    },
  });

  const migrateMutation = useMutation({
    mutationFn: async (value: StorageConfig) => {
      const payload: StorageMigrationPayload = { target: value };
      return services.adminTask.dispatchTask({
        task_type: storageMigrationTaskType,
        payload: JSON.stringify(payload),
      });
    },
    onSuccess: () => {
      toast.success('存储迁移任务已下发');
      void queryClient.invalidateQueries({
        queryKey: ['admin', 'storage-config'],
      });
    },
    onError: (error: Error) => {
      toast.error(error.message || '下发存储迁移任务失败');
      void queryClient.invalidateQueries({
        queryKey: ['admin', 'storage-config'],
      });
    },
  });
  const runMutation = useMutation({
    mutationFn: (executionID: string) =>
      services.adminTask.retryTaskExecution(executionID),
    onSuccess: () => {
      toast.success('存储迁移任务已重新下发');
      void queryClient.invalidateQueries({
        queryKey: ['admin', 'storage-config'],
      });
    },
    onError: (error: Error) => toast.error(error.message || '运行存储迁移失败'),
  });

  if (query.isPending || !config) {
    return (
      <div className='flex justify-center py-20'>
        <Loader2 className='animate-spin' />
      </div>
    );
  }

  const migration = query.data?.migration;
  const isReadOnly = migration ? migration.state !== 'idle' : false;
  const isFormDisabled =
    (migration
      ? migration.state === 'pending' || migration.state === 'running'
      : false) ||
    saveMutation.isPending ||
    migrateMutation.isPending;

  const updateObject = (
    driver: 's3' | 'r2' | 'minio' | 'oss',
    patch: Partial<ObjectStorageConfig>,
  ) => {
    setConfig((current) =>
      current
        ? {
            ...current,
            [driver]: { ...current[driver], ...patch },
          }
        : current,
    );
  };

  return (
    <div className='flex w-full flex-col gap-6'>
      {isReadOnly && migration && (
        <Card>
          <CardHeader>
            <CardTitle className='flex items-center gap-2'>
              存储维护模式
              <Badge
                variant={
                  migration.state === 'failed' ? 'destructive' : 'secondary'
                }
              >
                {migration.state}
              </Badge>
            </CardTitle>
            <CardDescription>
              {driverLabel(migration.source_driver)} →{' '}
              {driverLabel(migration.target_driver)}
              。迁移期间文件只允许读取，禁止上传、删除和清理。
            </CardDescription>
          </CardHeader>
          <CardContent className='flex flex-col gap-3'>
            <Progress
              value={migration.state === 'succeeded' ? 100 : undefined}
            />
            <p className='text-sm text-muted-foreground'>
              迁移进度请查看任务执行日志：{migration.task_id || '尚未下发'}
            </p>
            {migration.error && (
              <p className='text-sm text-destructive'>{migration.error}</p>
            )}
          </CardContent>
          <CardFooter>
            <Button
              variant='outline'
              disabled={
                migration.state !== 'failed' ||
                !migration.id ||
                runMutation.isPending
              }
              onClick={() => migration.id && runMutation.mutate(migration.id)}
            >
              {runMutation.isPending ? (
                <Loader2 data-icon='inline-start' className='animate-spin' />
              ) : (
                <Play data-icon='inline-start' />
              )}
              重试迁移
            </Button>
          </CardFooter>
        </Card>
      )}

      <Card className='border border-dashed shadow-sm'>
        <CardHeader className='border-b border-dashed pb-4'>
          <div className='flex items-center gap-2'>
            <div className='rounded-lg bg-indigo-500/10 p-1.5 text-indigo-500'>
              <Database className='size-4' />
            </div>
            <div>
              <CardTitle className='text-base font-semibold'>
                文件存储
              </CardTitle>
              <CardDescription className='text-xs'>
                默认使用本地存储。配置系统文件的存储媒介，切换存储类型且已有文件时，系统会自动进入维护模式并迁移文件。
              </CardDescription>
            </div>
          </div>
        </CardHeader>
        <CardContent className='pt-6'>
          <FieldGroup className='space-y-6'>
            <div className='grid grid-cols-1 gap-4 md:grid-cols-2'>
              <Field className='flex flex-col gap-1.5 md:col-span-2'>
                <FieldLabel className='text-xs font-semibold'>
                  存储类型
                </FieldLabel>
                <Select
                  value={config.driver}
                  disabled={isFormDisabled}
                  onValueChange={(value) =>
                    setConfig({ ...config, driver: value as StorageDriver })
                  }
                >
                  <SelectTrigger className='w-full border-dashed bg-card text-xs'>
                    <SelectValue />
                  </SelectTrigger>
                  <SelectContent>
                    <SelectGroup>
                      {(Object.keys(driverLabels) as StorageDriver[]).map(
                        (driver) => (
                          <SelectItem key={driver} value={driver}>
                            {driverLabels[driver]}
                          </SelectItem>
                        ),
                      )}
                    </SelectGroup>
                  </SelectContent>
                </Select>
              </Field>

              {config.driver === 'local' && (
                <div className='md:col-span-2'>
                  <TextField
                    label='根目录'
                    value={config.local.root}
                    placeholder='.'
                    onChange={(root) =>
                      setConfig({ ...config, local: { root } })
                    }
                  />
                </div>
              )}

              {(config.driver === 's3' ||
                config.driver === 'r2' ||
                config.driver === 'minio' ||
                config.driver === 'oss') && (
                <ObjectFields
                  driver={config.driver as 's3' | 'r2' | 'minio' | 'oss'}
                  value={config[config.driver as 's3' | 'r2' | 'minio' | 'oss']}
                  onChange={(patch) =>
                    updateObject(
                      config.driver as 's3' | 'r2' | 'minio' | 'oss',
                      patch,
                    )
                  }
                />
              )}

              {config.driver === 'webdav' && (
                <>
                  <div className='md:col-span-2'>
                    <TextField
                      label='服务地址'
                      value={config.webdav.endpoint}
                      placeholder='https://dav.example.com'
                      onChange={(endpoint) =>
                        setConfig({
                          ...config,
                          webdav: { ...config.webdav, endpoint },
                        })
                      }
                    />
                  </div>
                  <TextField
                    label='用户名'
                    value={config.webdav.username}
                    onChange={(username) =>
                      setConfig({
                        ...config,
                        webdav: { ...config.webdav, username },
                      })
                    }
                  />
                  <TextField
                    label='密码'
                    type='password'
                    value={config.webdav.password}
                    onChange={(password) =>
                      setConfig({
                        ...config,
                        webdav: { ...config.webdav, password },
                      })
                    }
                  />
                  <div className='md:col-span-2'>
                    <TextField
                      label='基础路径'
                      value={config.webdav.base_path}
                      placeholder='openflare'
                      onChange={(base_path) =>
                        setConfig({
                          ...config,
                          webdav: { ...config.webdav, base_path },
                        })
                      }
                    />
                  </div>
                </>
              )}
            </div>
          </FieldGroup>
        </CardContent>
        <CardFooter className='justify-end gap-2 flex-col sm:flex-row items-end sm:items-center border-t border-dashed pt-4 mt-6'>
          {config.driver !== query.data?.config.driver && (
            <span className='text-xs text-amber-500 mr-auto text-left max-w-md'>
              ⚠️
              您已切换存储类型。点击「保存配置」将立即切换活动存储引擎，并同步更新已有文件的存储驱动标记。仅在需要复制物理文件时才使用「开始迁移」。
            </span>
          )}
          <div className='flex gap-2'>
            <Button
              variant='outline'
              disabled={isFormDisabled}
              onClick={() => saveMutation.mutate(config)}
              className='border-dashed'
            >
              {saveMutation.isPending ? (
                <Loader2 data-icon='inline-start' className='animate-spin' />
              ) : (
                <Save data-icon='inline-start' />
              )}
              保存配置
            </Button>
            {config.driver !== query.data?.config.driver && (
              <Button
                disabled={isFormDisabled}
                onClick={() => migrateMutation.mutate(config)}
              >
                {migrateMutation.isPending ? (
                  <Loader2 data-icon='inline-start' className='animate-spin' />
                ) : (
                  <Play data-icon='inline-start' />
                )}
                开始迁移
              </Button>
            )}
          </div>
        </CardFooter>
      </Card>
    </div>
  );
}

function ObjectFields({
  driver,
  value,
  onChange,
}: {
  driver: 's3' | 'r2' | 'minio' | 'oss';
  value: ObjectStorageConfig;
  onChange: (patch: Partial<ObjectStorageConfig>) => void;
}) {
  return (
    <>
      {driver === 'r2' && (
        <div className='md:col-span-2'>
          <TextField
            label='Account ID'
            value={value.account_id || ''}
            onChange={(account_id) => onChange({ account_id })}
          />
        </div>
      )}
      {driver !== 's3' && (
        <div className='md:col-span-2'>
          <TextField
            label='Endpoint'
            value={value.endpoint}
            placeholder='https://...'
            onChange={(endpoint) => onChange({ endpoint })}
          />
        </div>
      )}
      <TextField
        label='Region'
        value={value.region}
        onChange={(region) => onChange({ region })}
      />
      <TextField
        label='Bucket'
        value={value.bucket}
        onChange={(bucket) => onChange({ bucket })}
      />
      <TextField
        label='Access Key ID'
        value={value.access_key_id}
        onChange={(access_key_id) => onChange({ access_key_id })}
      />
      <TextField
        label='Secret Access Key'
        type='password'
        value={value.secret_access_key}
        onChange={(secret_access_key) => onChange({ secret_access_key })}
      />
      <TextField
        label='对象前缀'
        value={value.key_prefix}
        placeholder='uploads'
        onChange={(key_prefix) => onChange({ key_prefix })}
      />
      <TextField
        label='CDN 地址'
        value={value.cdn_url}
        placeholder='https://cdn.example.com'
        onChange={(cdn_url) => onChange({ cdn_url })}
      />
      {(driver === 's3' || driver === 'minio') && (
        <div className='md:col-span-2'>
          <Field
            orientation='horizontal'
            className='flex items-center justify-between border border-dashed rounded-lg p-4 bg-muted/30'
          >
            <div className='flex flex-col gap-0.5'>
              <FieldLabel className='text-xs font-semibold cursor-pointer'>
                Path Style
              </FieldLabel>
              <FieldDescription className='text-[11px] leading-relaxed text-muted-foreground'>
                MinIO 等自托管 S3 通常需要开启。
              </FieldDescription>
            </div>
            <Switch
              checked={value.path_style}
              onCheckedChange={(path_style) => onChange({ path_style })}
            />
          </Field>
        </div>
      )}
    </>
  );
}

function TextField({
  label,
  value,
  onChange,
  placeholder,
  type = 'text',
}: {
  label: string;
  value: string;
  onChange: (value: string) => void;
  placeholder?: string;
  type?: React.HTMLInputTypeAttribute;
}) {
  return (
    <Field className='flex flex-col gap-1.5'>
      <FieldLabel className='text-xs font-semibold'>{label}</FieldLabel>
      <Input
        type={type}
        value={value}
        placeholder={placeholder}
        onChange={(event) => onChange(event.target.value)}
        className='border-dashed bg-card text-xs'
      />
    </Field>
  );
}