import { NextRequest, NextResponse } from 'next/server';
import { auth } from '@/app/(auth)/auth';
import { db } from '@/lib/db';
import { canvasProject } from '@/lib/db/schema';
import { syncCanvasNodesForProject } from '@/lib/db/queries';
import { resolveArchivedImageUrls } from '@/lib/storage/image-archive-db';
import { eq, and } from 'drizzle-orm';
import {
  buildStaleCanvasSaveConflictPayload,
  isStaleCanvasSaveBaseRevision,
} from '@/lib/canvas/canvas-save-conflict';

function resolveWorkspaceType(input: unknown) {
  return input === "agent" || input === "video" ? input : "canvas";
}

function getDefaultWorkspaceTitle(workspaceType: ReturnType<typeof resolveWorkspaceType>) {
  return workspaceType === "video" ? "未命名视频画布" : "未命名画布";
}

function shouldUseLocalCanvasE2E(request: NextRequest) {
  const hostname = request.nextUrl.hostname;
  return (
    process.env.CANVAS_E2E_LOCAL === "true" &&
    (hostname === "127.0.0.1" || hostname === "localhost" || hostname === "::1")
  );
}

function createLocalCanvasProject(
  id: string,
  input: {
    canvasData?: unknown;
    description?: unknown;
    thumbnail?: unknown;
    title?: unknown;
    workspaceType?: unknown;
  } = {}
) {
  const now = new Date().toISOString();
  const workspaceType = resolveWorkspaceType(input.workspaceType || "video");
  return {
    id,
    userId: "local-video-canvas-e2e-user",
    title: String(input.title || getDefaultWorkspaceTitle(workspaceType)),
    description: typeof input.description === "string" ? input.description : null,
    thumbnail: typeof input.thumbnail === "string" ? input.thumbnail : null,
    workspaceType,
    canvasData:
      input.canvasData && typeof input.canvasData === "object"
        ? input.canvasData
        : {
            nodes: [],
            edges: [],
            selectedNodeIds: [],
            viewport: { x: 0, y: 0, zoom: 1 },
            tool: "select",
          },
    createdAt: now,
    updatedAt: now,
  };
}

// 获取单个画布
export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const { id } = await params;
    if (shouldUseLocalCanvasE2E(request)) {
      return NextResponse.json({
        success: true,
        data: createLocalCanvasProject(id),
      });
    }

    const session = await auth();
    if (!session?.user?.id) {
      return NextResponse.json({ success: false, error: '未登录' }, { status: 401 });
    }

    const [project] = await db
      .select()
      .from(canvasProject)
      .where(
        and(
          eq(canvasProject.id, id),
          eq(canvasProject.userId, session.user.id)
        )
      );

    if (!project) {
      return NextResponse.json({ success: false, error: '画布不存在' }, { status: 404 });
    }

    return NextResponse.json({ success: true, data: project });
  } catch (error) {
    console.error('获取画布失败:', error);
    return NextResponse.json({ success: false, error: '获取画布失败' }, { status: 500 });
  }
}

// 更新画布（支持 upsert：如果不存在则创建）
export async function PUT(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const { id } = await params;
    const body = await request.json();
    if (shouldUseLocalCanvasE2E(request)) {
      return NextResponse.json({
        success: true,
        data: createLocalCanvasProject(id, body),
      });
    }

    const session = await auth();
    if (!session?.user?.id) {
      return NextResponse.json({ success: false, error: '未登录' }, { status: 401 });
    }

    const { title, description, canvasData } = body;
    const thumbnail = await resolveArchivedImageUrls(body.thumbnail);
    const baseCanvasRevision = body?.baseCanvasUpdatedAt || body?.baseCanvasRevision;
    const workspaceType =
      body && Object.prototype.hasOwnProperty.call(body, "workspaceType")
        ? resolveWorkspaceType(body.workspaceType)
        : undefined;

    // 先检查画布是否存在
    const [existingProject] = await db
      .select()
      .from(canvasProject)
      .where(
        and(
          eq(canvasProject.id, id),
          eq(canvasProject.userId, session.user.id)
        )
      );

    if (existingProject) {
      if (
        canvasData !== undefined &&
        baseCanvasRevision &&
        isStaleCanvasSaveBaseRevision({
          baseCanvasRevision: body?.baseCanvasRevision,
          baseCanvasUpdatedAt: body?.baseCanvasUpdatedAt,
          currentUpdatedAt: existingProject.updatedAt,
        })
      ) {
        return NextResponse.json(
          buildStaleCanvasSaveConflictPayload(existingProject.updatedAt),
          { status: 409 }
        );
      }

      const syncedCanvasData =
        canvasData !== undefined
          ? await syncCanvasNodesForProject({
              projectId: id,
              userId: session.user.id,
              canvasData,
            })
          : undefined;

      // 更新现有画布
      const updateData: any = { updatedAt: new Date() };
      if (title !== undefined) updateData.title = title;
      if (description !== undefined) updateData.description = description;
      if (thumbnail !== undefined) updateData.thumbnail = thumbnail;
      if (workspaceType !== undefined) updateData.workspaceType = workspaceType;
      if (syncedCanvasData !== undefined) updateData.canvasData = syncedCanvasData;

      const [updatedProject] = await db
        .update(canvasProject)
        .set(updateData)
        .where(
          and(
            eq(canvasProject.id, id),
            eq(canvasProject.userId, session.user.id)
          )
        )
        .returning();

      return NextResponse.json({ success: true, data: updatedProject });
    } else {
      const syncedCanvasData =
        canvasData !== undefined
          ? await syncCanvasNodesForProject({
              projectId: id,
              userId: session.user.id,
              canvasData,
            })
          : undefined;

      const nextWorkspaceType = workspaceType || "canvas";
      const nextCanvasData = syncedCanvasData || {
        nodes: [],
        edges: [],
        viewport: { x: 0, y: 0, zoom: 1 },
      };
      const nextTitle = title || getDefaultWorkspaceTitle(nextWorkspaceType);
      const insertData: any = {
        id, // 使用指定的 ID
        userId: session.user.id,
        title: nextTitle,
        workspaceType: nextWorkspaceType,
        canvasData: nextCanvasData,
      };
      const conflictUpdateData: any = {
        title: nextTitle,
        workspaceType: nextWorkspaceType,
        canvasData: nextCanvasData,
        updatedAt: new Date(),
      };
      if (description !== undefined) {
        insertData.description = description;
        conflictUpdateData.description = description;
      }
      if (thumbnail !== undefined) {
        insertData.thumbnail = thumbnail;
        conflictUpdateData.thumbnail = thumbnail;
      }

      // 创建新画布（使用指定 ID），并兼容同一用户并发创建同一画布的场景。
      const [newProject] = await db
        .insert(canvasProject)
        .values(insertData)
        .onConflictDoUpdate({
          target: canvasProject.id,
          set: conflictUpdateData,
          where: eq(canvasProject.userId, session.user.id),
        })
        .returning();

      if (!newProject) {
        return NextResponse.json(
          { success: false, error: '画布ID已被占用' },
          { status: 409 }
        );
      }

      return NextResponse.json({ success: true, data: newProject });
    }
  } catch (error) {
    console.error('更新/创建画布失败:', error);
    return NextResponse.json({ success: false, error: '更新画布失败' }, { status: 500 });
  }
}

// 删除画布
export async function DELETE(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const session = await auth();
    if (!session?.user?.id) {
      return NextResponse.json({ success: false, error: '未登录' }, { status: 401 });
    }

    const { id } = await params;

    const [deletedProject] = await db
      .delete(canvasProject)
      .where(
        and(
          eq(canvasProject.id, id),
          eq(canvasProject.userId, session.user.id)
        )
      )
      .returning();

    if (!deletedProject) {
      return NextResponse.json({ success: false, error: '画布不存在' }, { status: 404 });
    }

    return NextResponse.json({ success: true, data: deletedProject });
  } catch (error) {
    console.error('删除画布失败:', error);
    return NextResponse.json({ success: false, error: '删除画布失败' }, { status: 500 });
  }
}