/**
 * 文件：platform-chooser.ts
 * 作用：平台选择器组件，负责渲染平台选择 UI 并处理平台切换事件
 * 
 * 这是一个公共组件，独立于具体平台实现，便于未来扩展新平台
 */

import { Platform as ObsidianPlatform } from 'obsidian';

export type PlatformType = 'wechat' | 'xiaohongshu';

/**
 * 平台选择器配置
 */
export interface PlatformChooserOptions {
    /** 默认选中的平台 */
    defaultPlatform?: PlatformType;
    /** 平台切换回调 */
    onPlatformChange?: (platform: PlatformType) => Promise<void>;
}

export interface PlatformActionLabels {
    refresh: string;
    publish: string;
}

export interface PlatformChooserActions {
    onRefresh?: () => void | Promise<void>;
    onPublish?: () => void | Promise<void>;
    getLabels?: (platform: PlatformType) => PlatformActionLabels;
}

/**
 * 平台信息接口
 */
interface PlatformInfo {
    value: PlatformType;
    label: string;
    icon?: string;
}

/**
 * 支持的平台列表
 */
const SUPPORTED_PLATFORMS: PlatformInfo[] = [
    { value: 'wechat', label: '微信公众号', icon: '📱' },
    { value: 'xiaohongshu', label: '小红书', icon: '📔' }
];

/**
 * 平台选择器类
 * 
 * 职责：
 * 1. 渲染平台选择 UI
 * 2. 处理用户的平台切换操作
 * 3. 触发平台切换回调
 * 4. 维护当前选中的平台状态
 */
export class PlatformChooser {
    private container: HTMLElement;
    private selectElement: HTMLSelectElement | null = null;
    private refreshButton: HTMLButtonElement | null = null;
    private publishButton: HTMLButtonElement | null = null;
    private currentPlatform: PlatformType;
    private onChange?: (platform: PlatformType) => void;
    private actions: PlatformChooserActions | null = null;

    constructor(container: HTMLElement, options: PlatformChooserOptions = {}) {
        this.container = container;
        this.currentPlatform = options.defaultPlatform || 'xiaohongshu';
        if (options.onPlatformChange) {
            this.onChange = (platform) => {
                options.onPlatformChange!(platform);
            };
        }
    }

    /**
     * 设置平台切换回调
     */
    setOnChange(callback: (platform: PlatformType) => void): void {
        this.onChange = callback;
    }

    /**
     * 渲染平台选择器 UI
     */
    render(): void {
        // 将容器作为单层 Grid 行使用
        this.container.addClass('platform-selector-line');
        this.container.addClass('platform-chooser-grid');
        
        // 创建标签
        const platformLabel = this.container.createDiv({ cls: 'style-label' });
        platformLabel.innerText = '发布平台';
        
        // 创建选择器
        const platformSelect = this.container.createEl('select', { cls: 'platform-select' });
        this.selectElement = platformSelect;
        
        // 添加平台选项
        SUPPORTED_PLATFORMS.forEach(platform => {
            const option = platformSelect.createEl('option');
            option.value = platform.value;
            option.text = platform.icon ? `${platform.icon} ${platform.label}` : platform.label;
            
            // 设置默认选中
            if (platform.value === this.currentPlatform) {
                option.selected = true;
            }
        });
        
        // 绑定切换事件
        platformSelect.onchange = () => {
            const newPlatform = platformSelect.value as PlatformType;
            this.switchPlatformInternal(newPlatform);
        };

        // 刷新按钮
        this.refreshButton = this.container.createEl('button', { cls: 'toolbar-button purple-gradient' });
        this.refreshButton.onclick = () => this.handleRefreshClick();

        // 发布按钮
        this.publishButton = this.container.createEl('button', { cls: 'toolbar-button' });
        this.publishButton.onclick = () => this.handlePublishClick();

        this.updateActionLabels();
    }

    /**
     * 切换平台（内部方法）
     */
    private switchPlatformInternal(platform: PlatformType): void {
        if (platform === this.currentPlatform) {
            return; // 相同平台，不需要切换
        }

        console.log(`[PlatformChooser] 切换平台: ${this.currentPlatform} -> ${platform}`);
        
        this.currentPlatform = platform;
        
        // 触发平台切换回调
        if (this.onChange) {
            try {
                this.onChange(platform);
            } catch (error) {
                console.error('[PlatformChooser] 平台切换失败:', error);
            }
        }

        this.updateActionLabels();
    }

    /**
     * 切换平台（公共方法，供 PreviewManager 调用）
     */
    switchPlatform(platform: PlatformType): void {
        this.currentPlatform = platform;
        if (this.selectElement) {
            this.selectElement.value = platform;
        }
        this.updateActionLabels();
    }

    /**
     * 获取当前选中的平台
     */
    getCurrentPlatform(): PlatformType {
        return this.currentPlatform;
    }

    /**
     * 程序化设置平台（不触发回调）
     */
    setPlatform(platform: PlatformType): void {
        this.currentPlatform = platform;
        if (this.selectElement) {
            this.selectElement.value = platform;
        }
    }

    /**
     * 清理资源
     */
    destroy(): void {
        if (this.selectElement) {
            this.selectElement.onchange = null;
            this.selectElement = null;
        }
        if (this.refreshButton) {
            this.refreshButton.onclick = null;
            this.refreshButton = null;
        }
        if (this.publishButton) {
            this.publishButton.onclick = null;
            this.publishButton = null;
        }
    }

    /**
     * 设置通用操作按钮
     */
    setActions(actions: PlatformChooserActions): void {
        this.actions = actions;
        this.updateActionLabels();
    }

    private handleRefreshClick(): void {
        if (!this.actions?.onRefresh) return;
        Promise.resolve(this.actions.onRefresh()).catch((error) => {
            console.error('[PlatformChooser] 刷新操作失败:', error);
        });
    }

    private handlePublishClick(): void {
        if (!this.actions?.onPublish) return;
        Promise.resolve(this.actions.onPublish()).catch((error) => {
            console.error('[PlatformChooser] 发布操作失败:', error);
        });
    }

    private updateActionLabels(): void {
        if (!this.refreshButton || !this.publishButton) return;
        const labels = this.actions?.getLabels?.(this.currentPlatform) ?? {
            refresh: '🔄 刷新',
            publish: '📤 发布',
        };
        this.refreshButton.innerText = labels.refresh;
        this.publishButton.innerText = labels.publish;
    }
}