import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { upsertSystemSetting } from "@/lib/db/queries";
import { requireAgentWorkflowAdmin } from "@/lib/middleware/admin";
import {
  AGENT_PSD_TEMPLATES_KEY,
  getEditableAgentPsdTemplateLayers,
  isAgentPsdTextLayerSlot,
  normalizeAgentPsdTemplateStatus,
  parseAgentPsdTemplateLayers,
  type AgentPsdTemplateMutationResponse,
} from "@/lib/agents/psd-template-config";
import { preparePsdTemplateRenderAssets } from "@/lib/agents/psd-template-parser";
import { readAgentPsdFonts } from "@/lib/agents/psd-font-settings";
import { uploadFile } from "@/lib/storage/service";
import {
  readAgentPsdTemplates,
  tryDeleteAgentPsdTemplateAssets,
} from "@/lib/agents/psd-template-settings";

export const runtime = "nodejs";

const updateTemplateSchema = z.object({
  name: z.string().trim().min(1).max(80),
  description: z.string().optional().nullable(),
  status: z.string().optional(),
  layers: z.array(z.any()).default([]),
});

function jsonError(status: number, error: string) {
  const payload: AgentPsdTemplateMutationResponse = {
    success: false,
    error,
  };
  return NextResponse.json(payload, { status });
}

export async function GET(
  request: NextRequest,
  context: { params: Promise<{ id: string }> }
) {
  const session = await requireAgentWorkflowAdmin().catch(() => null);
  if (!session?.user?.id) {
    return jsonError(401, "未登录");
  }

  try {
    const { id } = await context.params;
    const templates = await readAgentPsdTemplates();
    const template = templates.find((entry) => entry.id === id);

    if (!template) {
      return jsonError(404, "未找到 PSD 模板");
    }

    return NextResponse.json({
      success: true,
      template,
    } satisfies AgentPsdTemplateMutationResponse);
  } catch (error) {
    console.error("[PSD Templates][Admin] get failed:", error);
    return jsonError(503, "PSD 模板读取失败");
  }
}

export async function PUT(
  request: NextRequest,
  context: { params: Promise<{ id: string }> }
) {
  const session = await requireAgentWorkflowAdmin().catch(() => null);
  if (!session?.user?.id) {
    return jsonError(401, "未登录");
  }

  let body: z.infer<typeof updateTemplateSchema>;
  try {
    body = updateTemplateSchema.parse(await request.json());
  } catch {
    return jsonError(400, "模板参数不合法");
  }

  try {
    const { id } = await context.params;
    const templates = await readAgentPsdTemplates();
    const currentTemplate = templates.find((entry) => entry.id === id);

    if (!currentTemplate) {
      return jsonError(404, "未找到 PSD 模板");
    }

    let nextLayers = parseAgentPsdTemplateLayers(body.layers);
    if (nextLayers.length === 0) {
      nextLayers = currentTemplate.layers;
    }

    if (
      normalizeAgentPsdTemplateStatus(body.status) === "active" &&
      getEditableAgentPsdTemplateLayers({
        ...currentTemplate,
        layers: nextLayers,
      }).length === 0
    ) {
      return jsonError(400, "至少配置一个可编辑图层后才能启用模板");
    }

    const fonts = await readAgentPsdFonts();
    const fontMap = new Map(fonts.map((font) => [font.id, font]));
    for (const layer of nextLayers) {
      if (!layer.isEditable || !isAgentPsdTextLayerSlot(layer)) {
        continue;
      }

      if (layer.fontId) {
        const matchedFont = fontMap.get(layer.fontId);
        if (!matchedFont) {
          return jsonError(400, `文字图层“${layer.layerName}”选择的字体不存在`);
        }

        layer.fontFamily = matchedFont.family;
        layer.fontLabel = matchedFont.name;
      }

      if (!String(layer.fontFamily || "").trim()) {
        return jsonError(400, `文字图层“${layer.layerName}”必须选择字体`);
      }
    }

    const preparedAssets = await preparePsdTemplateRenderAssets({
      templateId: currentTemplate.id,
      fileUrl: currentTemplate.fileUrl,
      layers: nextLayers,
    });
    nextLayers = preparedAssets.layers;
    const uploadedRenderBase = await uploadFile(
      `agent-psd-base-${currentTemplate.id}-${Date.now()}.png`,
      preparedAssets.renderBaseBuffer.buffer.slice(
        preparedAssets.renderBaseBuffer.byteOffset,
        preparedAssets.renderBaseBuffer.byteOffset + preparedAssets.renderBaseBuffer.byteLength
      ) as ArrayBuffer
    );

    const updatedTemplate = {
      ...currentTemplate,
      name: body.name.trim(),
      description: String(body.description || "").trim() || undefined,
      status: normalizeAgentPsdTemplateStatus(body.status),
      renderBaseUrl: uploadedRenderBase.url,
      renderBasePath: uploadedRenderBase.pathname,
      layers: nextLayers,
      layerCount: Math.max(currentTemplate.layerCount, nextLayers.length),
      updatedAt: new Date().toISOString(),
    };

    await upsertSystemSetting({
      key: AGENT_PSD_TEMPLATES_KEY,
      value: templates.map((template) =>
        template.id === currentTemplate.id ? updatedTemplate : template
      ),
      updatedBy: session.user.id,
    });

    return NextResponse.json({
      success: true,
      template: updatedTemplate,
    } satisfies AgentPsdTemplateMutationResponse);
  } catch (error) {
    console.error("[PSD Templates][Admin] update failed:", error);
    return jsonError(502, "PSD 模板保存失败");
  }
}

export async function DELETE(
  request: NextRequest,
  context: { params: Promise<{ id: string }> }
) {
  const session = await requireAgentWorkflowAdmin().catch(() => null);
  if (!session?.user?.id) {
    return jsonError(401, "未登录");
  }

  try {
    const { id } = await context.params;
    const templates = await readAgentPsdTemplates();
    const template = templates.find((entry) => entry.id === id);

    if (!template) {
      return jsonError(404, "未找到 PSD 模板");
    }

    await upsertSystemSetting({
      key: AGENT_PSD_TEMPLATES_KEY,
      value: templates.filter((entry) => entry.id !== id),
      updatedBy: session.user.id,
    });

    await tryDeleteAgentPsdTemplateAssets(template);

    return NextResponse.json({
      success: true,
      template,
    } satisfies AgentPsdTemplateMutationResponse);
  } catch (error) {
    console.error("[PSD Templates][Admin] delete failed:", error);
    return jsonError(502, "PSD 模板删除失败");
  }
}