import { join } from 'path';
import React, { useCallback, useState } from 'react';
import type { ExitState } from '../hooks/useExitOnCtrlCDWithKeybindings.js';
import { useTerminalSize } from '../hooks/useTerminalSize.js';
import { setClipboard, Box, Text, Byline, Dialog, KeyboardShortcutHint } from '@anthropic/ink';
import { useKeybinding } from '../keybindings/useKeybinding.js';
import { getCwd } from '../utils/cwd.js';
import { writeFileSync_DEPRECATED } from '../utils/slowOperations.js';
import { ConfigurableShortcutHint } from './ConfigurableShortcutHint.js';
import { Select } from './CustomSelect/select.js';
import TextInput from './TextInput.js';

type ExportDialogProps = {
  content: string;
  defaultFilename: string;
  onDone: (result: { success: boolean; message: string }) => void;
};

type ExportOption = 'clipboard' | 'file';

export function ExportDialog({ content, defaultFilename, onDone }: ExportDialogProps): React.ReactNode {
  const [, setSelectedOption] = useState<ExportOption | null>(null);
  const [filename, setFilename] = useState<string>(defaultFilename);
  const [cursorOffset, setCursorOffset] = useState<number>(defaultFilename.length);
  const [showFilenameInput, setShowFilenameInput] = useState(false);
  const { columns } = useTerminalSize();

  // Handle going back from filename input to option selection
  const handleGoBack = useCallback(() => {
    setShowFilenameInput(false);
    setSelectedOption(null);
  }, []);

  const handleSelectOption = async (value: string): Promise<void> => {
    if (value === 'clipboard') {
      // Copy to clipboard immediately
      const raw = await setClipboard(content);
      if (raw) process.stdout.write(raw);
      onDone({ success: true, message: 'Conversation copied to clipboard' });
    } else if (value === 'file') {
      setSelectedOption('file');
      setShowFilenameInput(true);
    }
  };

  const handleFilenameSubmit = () => {
    const finalFilename = filename.endsWith('.txt') ? filename : filename.replace(/\.[^.]+$/, '') + '.txt';
    const filepath = join(getCwd(), finalFilename);

    try {
      writeFileSync_DEPRECATED(filepath, content, {
        encoding: 'utf-8',
        flush: true,
      });
      onDone({
        success: true,
        message: `Conversation exported to: ${filepath}`,
      });
    } catch (error) {
      onDone({
        success: false,
        message: `Failed to export conversation: ${error instanceof Error ? error.message : 'Unknown error'}`,
      });
    }
  };

  // Dialog calls onCancel when Escape is pressed. If we are in the filename
  // input sub-screen, go back to the option list instead of closing entirely.
  const handleCancel = useCallback(() => {
    if (showFilenameInput) {
      handleGoBack();
    } else {
      onDone({ success: false, message: 'Export cancelled' });
    }
  }, [showFilenameInput, handleGoBack, onDone]);

  const options = [
    {
      label: 'Copy to clipboard',
      value: 'clipboard',
      description: 'Copy the conversation to your system clipboard',
    },
    {
      label: 'Save to file',
      value: 'file',
      description: 'Save the conversation to a file in the current directory',
    },
  ];

  // Custom input guide that changes based on dialog state
  function renderInputGuide(exitState: ExitState): React.ReactNode {
    if (showFilenameInput) {
      return (
        <Byline>
          <KeyboardShortcutHint shortcut="Enter" action="save" />
          <ConfigurableShortcutHint action="confirm:no" context="Confirmation" fallback="Esc" description="go back" />
        </Byline>
      );
    }

    if (exitState.pending) {
      return <Text>Press {exitState.keyName} again to exit</Text>;
    }

    return <ConfigurableShortcutHint action="confirm:no" context="Confirmation" fallback="Esc" description="cancel" />;
  }

  // Use Settings context so 'n' key doesn't cancel (allows typing 'n' in filename input)
  useKeybinding('confirm:no', handleCancel, {
    context: 'Settings',
    isActive: showFilenameInput,
  });

  return (
    <Dialog
      title="Export Conversation"
      subtitle="Select export method:"
      color="permission"
      onCancel={handleCancel}
      inputGuide={renderInputGuide}
      isCancelActive={!showFilenameInput}
    >
      {!showFilenameInput ? (
        <Select options={options} onChange={handleSelectOption} onCancel={handleCancel} />
      ) : (
        <Box flexDirection="column">
          <Text>Enter filename:</Text>
          <Box flexDirection="row" gap={1} marginTop={1}>
            <Text>&gt;</Text>
            <TextInput
              value={filename}
              onChange={setFilename}
              onSubmit={handleFilenameSubmit}
              focus={true}
              showCursor={true}
              columns={columns}
              cursorOffset={cursorOffset}
              onChangeCursorOffset={setCursorOffset}
            />
          </Box>
        </Box>
      )}
    </Dialog>
  );
}
