/**
 * @license
 * Copyright 2025 Vybestack LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import { vi } from 'bun:test';
import type { CommandContext } from '../ui/commands/types.js';
import type { LoadedSettings } from '../config/settings.js';
import type { GitService, Config, Logger } from '@vybestack/llxprt-code-core';
import type { SessionStatsState } from '../ui/contexts/SessionContext.js';

// A utility type to make all properties of an object, and its nested objects, partial.
type DeepPartial<T> = T extends object
  ? {
      [P in keyof T]?: DeepPartial<T[P]>;
    }
  : T;

/**
 * Creates a deep, fully-typed mock of the CommandContext for use in tests.
 * All functions are pre-mocked with `vi.fn()`.
 *
 * @param overrides - A deep partial object to override any default mock values.
 * @returns A complete, mocked CommandContext object.
 */
const buildDefaultMocks = (): CommandContext => ({
  invocation: {
    raw: '',
    name: '',
    args: '',
  },
  services: {
    config: {
      getEphemeralSetting: vi.fn(),
      setEphemeralSetting: vi.fn(),
      getAgentClient: vi.fn(),
      getSubagentManager: vi.fn(),
    } as unknown as Config,
    agent: null,
    settings: { merged: {} } as LoadedSettings,
    git: undefined as GitService | undefined,
    logger: {
      logMessage: vi.fn(),
    } as unknown as Logger, // Cast because Logger is a class.
    // Follow-up (#1569): Add profileManager and subagentManager when CommandContext interface is updated.
    // @plan:PLAN-20250117-SUBAGENTCONFIG.P07
  },
  ui: {
    addItem: vi.fn(),
    clear: vi.fn(),
    setDebugMessage: vi.fn(),
    pendingItem: null,
    setPendingItem: vi.fn(),
    loadHistory: vi.fn(),
    toggleCorgiMode: vi.fn(),
    toggleDebugProfiler: vi.fn(),
    toggleVimEnabled: vi.fn(),
    setLlxprtMdFileCount: vi.fn(),
    updateHistoryTokenCount: vi.fn(),
    reloadCommands: vi.fn(),
    extensionsUpdateState: new Map(),
    dispatchExtensionStateUpdate: vi.fn(),
    addConfirmUpdateExtensionRequest: vi.fn(),
    setExtensionsUpdateState: vi.fn(),
  } as unknown as CommandContext['ui'],
  session: {
    sessionShellAllowlist: new Set<string>(),
    stats: {
      sessionStartTime: new Date(),
      lastPromptTokenCount: 0,
      metrics: {
        models: {},
        tools: {
          totalCalls: 0,
          totalSuccess: 0,
          totalFail: 0,
          totalDurationMs: 0,
          totalDecisions: { accept: 0, reject: 0, modify: 0 },
          byName: {},
        },
      },
    } as SessionStatsState,
  },
});

export const createMockCommandContext = (
  overrides: DeepPartial<CommandContext> = {},
): CommandContext => {
  const defaultMocks: CommandContext = buildDefaultMocks();

  // Deep merge that preserves special objects (Dates, vitest mocks, etc.)
  const merge = (target: unknown, source: unknown): CommandContext => {
    const output = { ...(target as Record<string, unknown>) };

    for (const key in source as Record<string, unknown>) {
      if (Object.prototype.hasOwnProperty.call(source, key)) {
        const sourceValue = (source as Record<string, unknown>)[key];
        const targetValue = (output as Record<string, unknown>)[key];

        if (
          // We only want to recursively merge plain objects
          Object.prototype.toString.call(sourceValue) === '[object Object]' &&
          Object.prototype.toString.call(targetValue) === '[object Object]'
        ) {
          (output as Record<string, unknown>)[key] = merge(
            targetValue,
            sourceValue,
          );
        } else {
          // If not, we do a direct assignment. This preserves Date objects, vitest mocks, and others.
          (output as Record<string, unknown>)[key] = sourceValue;
        }
      }
    }
    return output as unknown as CommandContext;
  };

  return merge(defaultMocks, overrides);
};