import { getTemplateById, type VideoTemplate } from "@/lib/content/video-templates";

export type StoryboardScene = {
  id: string;
  title: string;
  visual: string;
  camera?: string;
  hostLine?: string;
  caption?: string;
  materialLabel?: string;
};

export type PromptMaterial = {
  id?: string;
  url: string;
  type: "image" | "video" | "audio";
  role?: string;
  label?: string;
  name?: string;
};

export type PromptAssemblyInput = {
  mode: "video" | "image";
  projectName?: string;
  audience?: string;
  offer?: string;
  brandLine?: string;
  selectedTemplateId?: string;
  manualPrompt?: string;
  storyboard?: StoryboardScene[];
  materials?: PromptMaterial[];
  imageGoal?: string;
  aspectRatio?: string;
};

export type PromptAssemblyResult = {
  prompt: string;
  scenes: StoryboardScene[];
  materials: PromptMaterial[];
  warnings: string[];
  blocked: boolean;
  requirements: {
    image: number;
    video: number;
    audio: number;
  };
};

export const defaultStoryboardScenes: StoryboardScene[] = [
  {
    id: "scene-1",
    title: "开场画面",
    visual: "用上传素材建立项目的第一印象，主体清晰，氛围干净",
    camera: "中景或推进镜头",
    hostLine: "",
    caption: "项目亮相"
  },
  {
    id: "scene-2",
    title: "场景氛围",
    visual: "展示空间、环境或使用场景，让观众理解项目所处的真实语境",
    camera: "横移或环绕",
    hostLine: "",
    caption: "场景氛围"
  },
  {
    id: "scene-3",
    title: "核心内容",
    visual: "突出核心产品、服务、活动、空间或人物，呈现最重要的信息",
    camera: "主体特写",
    hostLine: "",
    caption: "核心内容"
  },
  {
    id: "scene-4",
    title: "细节补充",
    visual: "补充质感、服务、流程、环境或亮点细节，增强可信度",
    camera: "细节切镜",
    hostLine: "",
    caption: "细节补充"
  },
  {
    id: "scene-5",
    title: "收尾画面",
    visual: "用项目名称、品牌信息或完整画面收束，形成清楚的结束印象",
    camera: "定格或拉远",
    hostLine: "",
    caption: "项目记忆点"
  }
];

export function assemblePrompt(input: PromptAssemblyInput): PromptAssemblyResult {
  const scenes = input.storyboard?.length ? input.storyboard : defaultStoryboardScenes;
  const materials = normalizeMaterials(input.materials || []);
  const template = input.selectedTemplateId ? getTemplateById(input.selectedTemplateId) : undefined;
  const prompt = input.manualPrompt?.trim()
    ? input.manualPrompt.trim()
    : input.mode === "image"
      ? assembleImagePrompt(input, scenes, template)
      : assembleVideoPrompt(input, scenes, template);
  const requirements = extractMaterialRequirements(prompt);
  const warnings = validateMaterialCoverage(requirements, materials);
  return {
    prompt,
    scenes,
    materials,
    warnings,
    blocked: false,
    requirements
  };
}

export function extractMaterialRequirements(prompt: string) {
  const requirements = { image: 0, video: 0, audio: 0 };
  for (const match of prompt.matchAll(/@(参考视频|图片|图|视频|音频)(\d*)/g)) {
    const kind = match[1];
    const index = match[2] ? Number(match[2]) : 1;
    if (kind === "图片" || kind === "图") requirements.image = Math.max(requirements.image, index);
    if (kind === "视频" || kind === "参考视频") requirements.video = Math.max(requirements.video, index);
    if (kind === "音频") requirements.audio = Math.max(requirements.audio, index);
  }
  return requirements;
}

export function normalizeMaterials(materials: PromptMaterial[]): PromptMaterial[] {
  const counters = { image: 0, video: 0, audio: 0 };
  return materials
    .filter((material) => material.url)
    .map((material) => {
      const type = material.type || inferMaterialType(material.url);
      counters[type] += material.label ? 0 : 1;
      return {
        ...material,
        type,
        label: material.label || labelFor(type, counters[type])
      };
    })
    .sort((a, b) => labelSortWeight(a.label) - labelSortWeight(b.label));
}

export function materialContentForProvider(materials: PromptMaterial[], origin: string) {
  return normalizeMaterials(materials).map((material) => {
    const url = toAbsoluteUrl(material.url, origin);
    if (material.type === "video") {
      return { type: "video_url", video_url: { url }, role: "reference_video", label: material.label };
    }
    if (material.type === "audio") {
      return { type: "audio_url", audio_url: { url }, role: "reference_audio", label: material.label };
    }
    return { type: "image_url", image_url: { url }, role: "reference_image", label: material.label };
  });
}

function assembleVideoPrompt(input: PromptAssemblyInput, scenes: StoryboardScene[], template?: VideoTemplate): string {
  const projectName = input.projectName?.trim() || "当前项目";
  const info = [
    `项目名称：${projectName}`,
    input.audience?.trim() ? `目标人群：${input.audience.trim()}` : "",
    input.offer?.trim() ? `表达重点：${input.offer.trim()}` : "",
    input.brandLine?.trim() ? `补充说明：${input.brandLine.trim()}` : ""
  ].filter(Boolean).join("\n");
  const templateText = template
    ? `参考模板：「${template.title}」。${template.referenceVideoUrl ? "参考@视频1的画面节奏、转场方式和整体质感。" : "提取模板的节奏、画面组织、转场和视觉气质。"}模板风格说明：${template.seedanceInstruction || template.prompt.slice(0, 180)}。只迁移模板风格和结构，最终内容以项目名称和上传素材为准。`
    : "参考风格：真实自然的营销宣传片，画面干净、节奏清楚、转场自然。";
  const sceneText = scenes
    .map((scene, index) => {
      const label = scene.materialLabel || `@图片${index + 1}`;
      return `${index + 1}. ${scene.title}：素材参考=${label}；内容方向=${scene.visual}${scene.camera ? `；镜头=${scene.camera}` : ""}${scene.hostLine ? `；口播=${scene.hostLine}` : ""}${scene.caption ? `；字幕=${scene.caption}` : ""}`;
    })
    .join("\n");
  return `通用营销宣传视频。
${templateText}
${info}
内容结构：
${sceneText}
生成要求：
- 以项目名称和@素材为准，不套用示例中的具体地点、人物、文案或品牌。
- 图片素材用于控制主体、场景、商品和分镜；视频素材用于控制节奏、转场、运镜或参考风格。
- 画面真实干净，主体清晰，转场自然，整体观感统一。
- 如生成字幕，只保留简短标题或重点信息，避免大段文字。
- 不额外添加与项目无关的信息。`;
}

function assembleImagePrompt(input: PromptAssemblyInput, scenes: StoryboardScene[], template?: VideoTemplate): string {
  const projectName = input.projectName?.trim() || "当前项目";
  const imageGoal = input.imageGoal?.trim() || "生成可用于营销传播的主视觉图片";
  const sceneText = scenes
    .slice(0, 4)
    .map((scene, index) => {
      const label = scene.materialLabel || `@图片${index + 1}`;
      return `${index + 1}. ${scene.title}：参考素材=${label}；画面要点=${scene.visual}${scene.caption ? `；文字元素=${scene.caption}` : ""}`;
    })
    .join("\n");
  const templateText = template
    ? `可借鉴视频模板「${template.title}」的节奏感、镜头气质和画面组织，但输出为单张高质量营销图片。`
    : "整体风格真实、有设计感，适合品牌和社媒传播。";
  return `营销图片生成。
项目名称：${projectName}
目标：${imageGoal}
目标人群：${input.audience?.trim() || "泛营销受众"}
表达重点：${input.offer?.trim() || "突出产品、服务或活动核心卖点"}
补充说明：${input.brandLine?.trim() || "保持干净、可信、可发布的视觉质感"}
${templateText}
素材引用：
${sceneText}
生成要求：
- 严格参考提示词中的@图片素材，保持主体和关键信息一致。
- 可以使用视频素材作为节奏、镜头或氛围参考，但最终输出单张图片。
- 图片比例：${input.aspectRatio || "1:1"}。
- 文字内容少而准确，避免错别字和无关标语。
- 不额外添加与项目无关的信息。`;
}

function validateMaterialCoverage(requirements: { image: number; video: number; audio: number }, materials: PromptMaterial[]) {
  const available = materials.reduce((acc, material) => {
    acc[material.type] += 1;
    return acc;
  }, { image: 0, video: 0, audio: 0 });
  const warnings = [];
  if (requirements.image > available.image) warnings.push(`提示词引用到 @图片${requirements.image}，当前只绑定了 ${available.image} 张图片。`);
  if (requirements.video > available.video) warnings.push(`提示词引用到 @视频${requirements.video}，当前只绑定了 ${available.video} 个视频。`);
  if (requirements.audio > available.audio) warnings.push(`提示词引用到 @音频${requirements.audio}，当前只绑定了 ${available.audio} 个音频。`);
  return warnings;
}

function labelFor(type: PromptMaterial["type"], index: number): string {
  if (type === "video") return `@视频${index}`;
  if (type === "audio") return `@音频${index}`;
  return `@图片${index}`;
}

function labelSortWeight(label?: string): number {
  const match = label?.match(/^@(图片|图|视频|音频)(\d+)$/);
  if (!match) return 999;
  const base = match[1] === "图片" || match[1] === "图" ? 0 : match[1] === "视频" ? 100 : 200;
  return base + Number(match[2]);
}

function inferMaterialType(url: string): PromptMaterial["type"] {
  const lower = url.toLowerCase();
  if (/\.(mp4|mov|webm)(\?|$)/.test(lower)) return "video";
  if (/\.(mp3|wav|m4a|aac|flac)(\?|$)/.test(lower)) return "audio";
  return "image";
}

function toAbsoluteUrl(url: string, origin: string): string {
  if (/^https?:\/\//i.test(url) || url.startsWith("data:")) return url;
  return new URL(url, origin).toString();
}