import chalk from 'chalk';

import { isAI } from '../helpers.js';

export type OutputFormat = 'table' | 'plain' | 'json' | 'graph';

export function resolveFormat(argv: { format?: string }): OutputFormat {
  if (
    argv.format === 'table' ||
    argv.format === 'plain' ||
    argv.format === 'json' ||
    argv.format === 'graph'
  )
    return argv.format;
  if (isAI()) return 'json';
  return 'plain';
}

export function formatPlainTable(headers: string[], rows: string[][]): string {
  if (rows.length === 0) return '';

  const colWidths = headers.map((h, i) =>
    Math.max(h.length, ...rows.map((r) => (r[i] ?? '').length))
  );

  const headerLine = headers.map((h, i) => h.toUpperCase().padEnd(colWidths[i]!)).join('\t');
  const bodyLines = rows.map((row) => row.map((cell, i) => cell.padEnd(colWidths[i]!)).join('\t'));

  return [headerLine, ...bodyLines].join('\n');
}

export function formatPrettyTable(headers: string[], rows: string[][]): string {
  if (rows.length === 0) return chalk.dim('  No data found.');

  const colWidths = headers.map((h, i) =>
    Math.max(h.length, ...rows.map((r) => (r[i] ?? '').length))
  );

  const headerLine = headers.map((h, i) => chalk.bold(h.padEnd(colWidths[i]!))).join('  ');
  const separator = chalk.dim(colWidths.map((w) => '\u2500'.repeat(w)).join('\u2500\u2500'));
  const bodyLines = rows.map((row) => row.map((cell, i) => cell.padEnd(colWidths[i]!)).join('  '));

  return [headerLine, separator, ...bodyLines].join('\n');
}

function gradientBar(len: number, rgb: [number, number, number]): string {
  let result = '';
  for (let i = 0; i < len; i++) {
    const t = len === 1 ? 1 : i / (len - 1);
    const dim = 0.3 + t * 0.7;
    const r = Math.round(rgb[0] * dim);
    const g = Math.round(rgb[1] * dim);
    const b = Math.round(rgb[2] * dim);
    result += chalk.rgb(r, g, b)('\u2588');
  }
  return result;
}

const COLOR_MAP: Record<string, [number, number, number]> = {
  cyan: [0, 255, 255],
  magenta: [255, 0, 255],
  yellow: [255, 255, 0],
  green: [0, 255, 100],
  blue: [80, 140, 255],
  red: [255, 80, 80],
};

export function formatBarChart(
  items: { label: string; value: number; color?: string }[],
  opts: { maxWidth?: number } = {}
): string {
  if (items.length === 0) return chalk.dim('  No data found.');

  const maxWidth = opts.maxWidth ?? 40;
  const maxVal = Math.max(...items.map((i) => i.value), 1);
  const maxLabel = Math.max(...items.map((i) => i.label.length));
  const maxValStr = Math.max(...items.map((i) => i.value.toLocaleString('en-US').length));

  return items
    .map((item) => {
      const barLen = Math.round((item.value / maxVal) * maxWidth);
      const rgb = COLOR_MAP[item.color ?? 'cyan'] ?? COLOR_MAP.cyan!;
      const bar = barLen > 0 ? gradientBar(barLen, rgb) : '';
      const pad = ' '.repeat(maxWidth - barLen);
      return `  ${item.label.padEnd(maxLabel)}  ${bar}${pad} ${item.value.toLocaleString('en-US').padStart(maxValStr)}`;
    })
    .join('\n');
}

export function formatOutput(
  format: OutputFormat,
  headers: string[],
  rows: string[][],
  jsonData: unknown
): string {
  if (format === 'json') return JSON.stringify(jsonData, null, 2);
  if (format === 'plain') return formatPlainTable(headers, rows);
  return formatPrettyTable(headers, rows);
}