/**
 * Plugin/Callback interface for ink-terminal.
 *
 * All app-specific dependencies are injected via configure(),
 * rather than hardcoded imports. This keeps the rendering engine
 * decoupled from any specific application.
 *
 * All callbacks are on COLD paths (logging, lifecycle).
 * Hot paths (cellAt, diffEach, setCellAt, blitRegion) have
 * ZERO external dependency calls.
 */

export type InkTerminalConfig = {
	/**
	 * Debug logging function. Called throughout the rendering pipeline.
	 * Default: no-op
	 * Replaces: src/utils/debug.ts logForDebugging (used in 7 files)
	 */
	logForDebugging?: (message: string, opts?: { level: string }) => void

	/**
	 * Error logging function.
	 * Default: console.error
	 * Replaces: src/utils/log.ts logError (used in 2 files)
	 */
	logError?: (message: string, ...args: unknown[]) => void

	/**
	 * Terminal name for capability detection.
	 * Default: auto-detect from TERM_PROGRAM env var
	 * Replaces: src/utils/env.ts env.terminal
	 */
	terminalName?: string

	/**
	 * Called before each frame render.
	 * Default: no-op
	 * Replaces: src/bootstrap/state.ts flushInteractionTime
	 */
	onBeforeRender?: () => void

	/**
	 * Called when scroll activity occurs.
	 * Default: no-op
	 * Replaces: src/bootstrap/state.ts markScrollActivity
	 */
	onScrollActivity?: () => void

	/**
	 * Called when interaction time should be updated.
	 * Default: no-op
	 * Replaces: src/bootstrap/state.ts updateLastInteractionTime
	 */
	onInteraction?: (immediate?: boolean) => void

	/**
	 * Environment variable truthiness check.
	 * Default: checks '1', 'true', 'yes'
	 * Replaces: src/utils/envUtils.ts isEnvTruthy
	 */
	isEnvTruthy?: (value: string | boolean | undefined) => boolean

	/**
	 * Called when first stdin data is received.
	 * Default: no-op
	 * Replaces: src/utils/earlyInput.ts stopCapturingEarlyInput
	 */
	onFirstInput?: () => void

	/**
	 * Whether mouse clicks are disabled.
	 * Default: () => false
	 * Replaces: src/utils/fullscreen.ts isMouseClicksDisabled
	 */
	isMouseClicksDisabled?: () => boolean
}

// Module-level singleton with sensible defaults
let _config: Required<InkTerminalConfig> = {
	logForDebugging: () => {},
	logError: console.error,
	terminalName: process.env.TERM_PROGRAM ?? '',
	onBeforeRender: () => {},
	onScrollActivity: () => {},
	onInteraction: () => {},
	isEnvTruthy: (v) => v === true || v === '1' || v === 'true' || v === 'yes',
	onFirstInput: () => {},
	isMouseClicksDisabled: () => false,
}

/**
 * Configure ink-terminal with application-specific callbacks.
 * Call this once during application bootstrap, before any rendering.
 *
 * @example
 * ```typescript
 * import { configure } from 'ink-terminal'
 *
 * configure({
 *   logForDebugging: (msg) => console.debug(`[ink] ${msg}`),
 *   terminalName: 'my-app',
 * })
 * ```
 */
export function configure(config: Partial<InkTerminalConfig>): void {
	_config = { ..._config, ...config }
}

/**
 * Get the current configuration.
 * Used internally by rendering engine modules.
 */
export function getConfig(): Required<InkTerminalConfig> {
	return _config
}