export const SCENE_FUSION_ASPECT_RATIO_OPTIONS = [
  { label: "自动", value: "auto" },
  { label: "1:1", value: "1:1" },
  { label: "4:3", value: "4:3" },
  { label: "3:4", value: "3:4" },
  { label: "16:9", value: "16:9" },
  { label: "9:16", value: "9:16" },
] as const;

export const SCENE_FUSION_IMAGE_SIZE_OPTIONS = [
  { label: "标准 (1K)", value: "1K" },
  { label: "高清 (2K)", value: "2K" },
  { label: "超清 (4K)", value: "4K" },
] as const;

export type SceneFusionAspectRatioValue =
  (typeof SCENE_FUSION_ASPECT_RATIO_OPTIONS)[number]["value"];
export type SceneFusionImageSizeValue =
  (typeof SCENE_FUSION_IMAGE_SIZE_OPTIONS)[number]["value"];

export type SceneFusionImageGenConfig = {
  supportsSize?: boolean;
  supports1K?: boolean;
  supports2K?: boolean;
  supports4K?: boolean;
};

export type SceneFusionCapabilityCandidate = {
  model: {
    id: string;
    displayName: string;
    imageGenConfig?: SceneFusionImageGenConfig | null;
  };
  provider: {
    type: string;
  };
};

export type SceneFusionCapabilitySummary = {
  strategy: "preferred-model" | "candidate-intersection" | "fallback-default";
  strategyLabel: string;
  preferredModelId: string | null;
  preferredModelName: string | null;
  candidateCount: number;
  note: string | null;
  aspectRatio: {
    enabled: boolean;
    options: SceneFusionAspectRatioValue[];
    defaultValue: SceneFusionAspectRatioValue;
  };
  imageSize: {
    enabled: boolean;
    options: SceneFusionImageSizeValue[];
    defaultValue: SceneFusionImageSizeValue;
  };
};

const DEFAULT_ASPECT_RATIO: SceneFusionAspectRatioValue = "auto";
const DEFAULT_IMAGE_SIZE: SceneFusionImageSizeValue = "2K";

const ALL_ASPECT_RATIO_VALUES = SCENE_FUSION_ASPECT_RATIO_OPTIONS.map(
  (option) => option.value
);
const ALL_IMAGE_SIZE_VALUES = SCENE_FUSION_IMAGE_SIZE_OPTIONS.map((option) => option.value);

export function normalizeSceneFusionProviderType(providerType: string): string {
  return providerType === "gemini-image" ? "gemini" : providerType;
}

export function canProcessSceneFusionProviderType(providerType: string): boolean {
  const normalized = normalizeSceneFusionProviderType(providerType);
  switch (normalized) {
    case "alibaba-image":
    case "ruxa-image":
    case "fal-image":
    case "openai-image":
    case "gemini":
    case "volcano-vision":
      return true;
    default:
      return false;
  }
}

function orderedIntersect<T extends string>(base: readonly T[], groups: T[][]): T[] {
  if (groups.length === 0) return [...base];
  return base.filter((item) => groups.every((group) => group.includes(item)));
}

function getSupportedAspectRatiosByProvider(providerType: string): SceneFusionAspectRatioValue[] {
  switch (normalizeSceneFusionProviderType(providerType)) {
    case "volcano-vision":
      return [];
    case "ruxa-image":
      return ["1:1", "4:3", "3:4", "16:9", "9:16"];
    case "alibaba-image":
    case "fal-image":
    case "openai-image":
    case "gemini":
    default:
      return [...ALL_ASPECT_RATIO_VALUES];
  }
}

function getSupportedImageSizesByConfig(
  imageGenConfig?: SceneFusionImageGenConfig | null
): SceneFusionImageSizeValue[] {
  if (imageGenConfig?.supportsSize === false) {
    return [];
  }

  return ALL_IMAGE_SIZE_VALUES.filter((value) => {
    if (value === "1K") return imageGenConfig?.supports1K !== false;
    if (value === "2K") return imageGenConfig?.supports2K !== false;
    if (value === "4K") return imageGenConfig?.supports4K !== false;
    return true;
  });
}

function pickDefaultAspectRatio(
  options: SceneFusionAspectRatioValue[]
): SceneFusionAspectRatioValue {
  return (
    options.find((value) => value === DEFAULT_ASPECT_RATIO) ||
    options.find((value) => value === "1:1") ||
    options[0] ||
    DEFAULT_ASPECT_RATIO
  );
}

function pickDefaultImageSize(options: SceneFusionImageSizeValue[]): SceneFusionImageSizeValue {
  return (
    options.find((value) => value === DEFAULT_IMAGE_SIZE) ||
    options.find((value) => value === "1K") ||
    options.find((value) => value === "4K") ||
    options[0] ||
    DEFAULT_IMAGE_SIZE
  );
}

export function getSceneFusionCandidateCapability(candidate: SceneFusionCapabilityCandidate) {
  const aspectRatioOptions = getSupportedAspectRatiosByProvider(candidate.provider.type);
  const imageSizeOptions = getSupportedImageSizesByConfig(candidate.model.imageGenConfig);

  return {
    aspectRatio: {
      enabled: aspectRatioOptions.length > 0,
      options: aspectRatioOptions,
      defaultValue: pickDefaultAspectRatio(aspectRatioOptions),
    },
    imageSize: {
      enabled: imageSizeOptions.length > 0,
      options: imageSizeOptions,
      defaultValue: pickDefaultImageSize(imageSizeOptions),
    },
  };
}

export function buildSceneFusionCapabilitySummary(
  candidates: SceneFusionCapabilityCandidate[],
  preferredModelId?: string | null
): SceneFusionCapabilitySummary {
  const supportedCandidates = candidates.filter((candidate) =>
    canProcessSceneFusionProviderType(candidate.provider.type)
  );

  if (supportedCandidates.length === 0) {
    return {
      strategy: "fallback-default",
      strategyLabel: "未检测到可用模型，使用默认参数",
      preferredModelId: null,
      preferredModelName: null,
      candidateCount: 0,
      note: "后台当前没有可用于批量处理的生图模型，以下参数仅作为默认值展示。",
      aspectRatio: {
        enabled: true,
        options: [...ALL_ASPECT_RATIO_VALUES],
        defaultValue: DEFAULT_ASPECT_RATIO,
      },
      imageSize: {
        enabled: true,
        options: [...ALL_IMAGE_SIZE_VALUES],
        defaultValue: DEFAULT_IMAGE_SIZE,
      },
    };
  }

  const preferredCandidate =
    preferredModelId
      ? supportedCandidates.find((candidate) => candidate.model.id === preferredModelId) || null
      : null;

  const sourceCandidates = preferredCandidate ? [preferredCandidate] : supportedCandidates;
  const strategy = preferredCandidate ? "preferred-model" : "candidate-intersection";
  const aspectRatioOptions = orderedIntersect(
    ALL_ASPECT_RATIO_VALUES,
    sourceCandidates.map((candidate) => getSceneFusionCandidateCapability(candidate).aspectRatio.options)
  );
  const imageSizeOptions = orderedIntersect(
    ALL_IMAGE_SIZE_VALUES,
    sourceCandidates.map((candidate) => getSceneFusionCandidateCapability(candidate).imageSize.options)
  );

  return {
    strategy,
    strategyLabel: preferredCandidate
      ? `按首选模型 ${preferredCandidate.model.displayName} 的能力展示`
      : `未指定首选模型，按 ${supportedCandidates.length} 个候选模型交集展示`,
    preferredModelId: preferredCandidate?.model.id || null,
    preferredModelName: preferredCandidate?.model.displayName || null,
    candidateCount: supportedCandidates.length,
    note: preferredCandidate
      ? supportedCandidates.length > 1
        ? "当首选模型失败回退到其他模型时，系统会自动按目标模型能力降级不支持的参数。"
        : "当前仅使用一个模型，参数会严格按该模型能力生效。"
      : "多模型轮换时，不支持的参数已在前端按交集隐藏，后端也会继续做能力兜底。",
    aspectRatio: {
      enabled: aspectRatioOptions.length > 0,
      options: aspectRatioOptions,
      defaultValue: pickDefaultAspectRatio(aspectRatioOptions),
    },
    imageSize: {
      enabled: imageSizeOptions.length > 0,
      options: imageSizeOptions,
      defaultValue: pickDefaultImageSize(imageSizeOptions),
    },
  };
}

export function normalizeSceneFusionOutputParamsForCandidate(
  candidate: SceneFusionCapabilityCandidate,
  requested: {
    aspectRatio?: string | null;
    imageSize?: string | null;
  }
) {
  const capability = getSceneFusionCandidateCapability(candidate);
  const requestedAspectRatio = String(requested.aspectRatio || "").trim() as SceneFusionAspectRatioValue;
  const requestedImageSize = String(requested.imageSize || "").trim().toUpperCase() as SceneFusionImageSizeValue;

  const aspectRatio =
    !capability.aspectRatio.enabled
      ? undefined
      : capability.aspectRatio.options.includes(requestedAspectRatio)
        ? requestedAspectRatio
        : requestedAspectRatio
          ? capability.aspectRatio.defaultValue
          : undefined;

  const imageSize =
    !capability.imageSize.enabled
      ? undefined
      : capability.imageSize.options.includes(requestedImageSize)
        ? requestedImageSize
        : requestedImageSize
          ? capability.imageSize.defaultValue
          : undefined;

  const changes: string[] = [];
  if (requestedAspectRatio && aspectRatio !== requestedAspectRatio) {
    changes.push(
      aspectRatio
        ? `aspectRatio:${requestedAspectRatio}->${aspectRatio}`
        : `aspectRatio:${requestedAspectRatio}->default`
    );
  }
  if (requestedImageSize && imageSize !== requestedImageSize) {
    changes.push(
      imageSize
        ? `imageSize:${requestedImageSize}->${imageSize}`
        : `imageSize:${requestedImageSize}->default`
    );
  }

  return {
    aspectRatio,
    imageSize,
    changed: changes.length > 0,
    changes,
  };
}