import { createLanguageModelFromResolved } from "@tasks/ai";
import {
  markdownBacklogItems,
  modelProviders,
  roleModelRoutes,
} from "@tasks/database/schema";
import {
  convoyObjectContentSchema,
  GATE_INBOX_STATUSES,
} from "@tasks/shared/convoy-lifecycle";
import {
  providerTypeSchema,
  resolveModel,
  type ModelProvider,
  type RoleModelRoute,
} from "@tasks/shared/model-routing";
import { TRPCError } from "@trpc/server";
import { generateText, tool } from "ai";
import { asc, eq } from "drizzle-orm";
import { z } from "zod";

import {
  listConvoyProjects,
  loadConvoyProject,
} from "@/server/lib/convoy/convoy-service";
import { router, workspaceProcedure } from "@/server/trpc";
import type { WorkspaceProcedureContext } from "@/server/trpc";

type ProviderRow = typeof modelProviders.$inferSelect;
type RouteRow = typeof roleModelRoutes.$inferSelect;

function mapProviderRow(row: ProviderRow): ModelProvider {
  return {
    id: row.id,
    workspaceId: row.workspaceId,
    alias: row.alias,
    displayName: row.displayName,
    providerType: providerTypeSchema.parse(row.providerType),
    modelId: row.modelId,
    baseUrl: row.baseUrl,
    apiKeyEnvVar: row.apiKeyEnvVar,
    extraHeaders: row.extraHeaders,
    defaultParams: row.defaultParams,
    metadata: row.metadata,
    enabled: row.enabled,
  };
}

function mapRouteRow(row: RouteRow): RoleModelRoute {
  return {
    id: row.id,
    workspaceId: row.workspaceId,
    roleId: row.roleId,
    providerAliasId: row.providerAliasId,
    enabled: row.enabled,
    sortOrder: row.sortOrder,
  };
}

function readApiKey(envVarName: string): string | undefined {
  return process.env[envVarName]?.trim() || undefined;
}

function assertWorkspaceAdmin(_ctx: WorkspaceProcedureContext): void {
  // ops copilot is read-only; no admin check needed, but keep helper for future
  void _ctx;
}

const OPS_SYSTEM_PROMPT =
  "You are ops copilot for second brain OS. You help owners triage \"what needs me?\" across fleet, convoys and backlog. " +
  "Use the provided tools (fleetStatus, convoyGet, backlogListTree) to ground answers. " +
  "Always respond with links in form [workspaceSlug/convoySlug] for convoys and [workspaceSlug/planSlug/epicSlug/taskSlug] for backlog items. " +
  "Show fleet → needs you citations when answering gate questions. Be concise, actionable, no secrets.";

const messageSchema = z.object({
  role: z.enum(["user", "assistant"]),
  content: z.string().min(1).max(4000),
});

export const opsCopilotRouter = router({
  generateText: workspaceProcedure
    .input(
      z.object({
        workspace: z.string().min(1),
        prompt: z.string().min(1).max(4000),
        messages: z.array(messageSchema).optional(),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      void assertWorkspaceAdmin(ctx);

      const providerRows = await ctx.db
        .select()
        .from(modelProviders)
        .where(eq(modelProviders.workspaceId, ctx.workspace.id))
        .orderBy(asc(modelProviders.alias));

      const routeRows = await ctx.db
        .select()
        .from(roleModelRoutes)
        .where(eq(roleModelRoutes.workspaceId, ctx.workspace.id));

      const resolved = resolveModel({
        roleId: "gate-copilot",
        providers: providerRows.map(mapProviderRow),
        routes: routeRows.map(mapRouteRow),
        getApiKey: readApiKey,
      });

      if (!resolved.ok) {
        throw new TRPCError({
          code: "BAD_REQUEST",
          message: resolved.error.message,
        });
      }

      const modelResult = createLanguageModelFromResolved(resolved.model);
      if (!modelResult.ok) {
        throw new TRPCError({
          code: "BAD_REQUEST",
          message: modelResult.reason,
        });
      }

      // Bounded, workspace-scoped, read-only tools (<3 tools)
      const fleetStatusTool = tool({
        description:
          "Get fleet gate inbox needing you for this workspace. Returns up to 10 gate items with links [workspaceSlug/convoySlug].",
        parameters: z.object({}),
        execute: async () => {
          const convoys = await listConvoyProjects(ctx.db, ctx.workspace.id);
          const gateInbox = convoys.filter((c) =>
            (GATE_INBOX_STATUSES as readonly string[]).includes(c.status),
          );
          const bounded = gateInbox.slice(0, 10);
          const payload = {
            workspace: ctx.workspace.slug,
            totalNeedingYou: gateInbox.length,
            items: bounded.map((c) => ({
              convoyId: c.id,
              convoySlug: c.content?.convoySlug ?? c.title,
              status: c.status,
              classification: c.content?.classification ?? null,
              updatedAt: c.updatedAt.toISOString(),
              link: `${ctx.workspace.slug}/${c.content?.convoySlug ?? c.id}`,
            })),
          };
          return JSON.stringify(payload);
        },
      });

      const convoyGetTool = tool({
        description: "Get one convoy by id (workspace-scoped, read-only).",
        parameters: z.object({
          convoyId: z.string().uuid(),
        }),
        execute: async ({ convoyId }: { convoyId: string }) => {
          const convoy = await loadConvoyProject(ctx.db, ctx.workspace.id, convoyId);
          if (!convoy) {
            return JSON.stringify({ error: "Convoy not found in this workspace" });
          }
          const content = convoyObjectContentSchema.safeParse(convoy.content);
          const payload = {
            id: convoy.id,
            title: convoy.title,
            status: convoy.status ?? "draft",
            description: convoy.description ? convoy.description.slice(0, 1000) : null,
            content: content.success ? content.data : null,
            updatedAt: convoy.updatedAt.toISOString(),
            link: `${ctx.workspace.slug}/${content.success ? content.data.convoySlug : convoy.title}`,
          };
          return JSON.stringify(payload);
        },
      });

      const backlogListTreeTool = tool({
        description:
          "List backlog tree (plans/epics/tasks) for this workspace. Bounded to 20 items, read-only.",
        parameters: z.object({}),
        execute: async () => {
          const rows = await ctx.db
            .select({
              id: markdownBacklogItems.id,
              kind: markdownBacklogItems.kind,
              slug: markdownBacklogItems.slug,
              planSlug: markdownBacklogItems.planSlug,
              epicSlug: markdownBacklogItems.epicSlug,
              title: markdownBacklogItems.title,
              status: markdownBacklogItems.status,
              priority: markdownBacklogItems.priority,
              repoPath: markdownBacklogItems.repoPath,
              updatedAt: markdownBacklogItems.updatedAt,
            })
            .from(markdownBacklogItems)
            .where(eq(markdownBacklogItems.workspaceId, ctx.workspace.id))
            .orderBy(asc(markdownBacklogItems.planSlug), asc(markdownBacklogItems.kind), asc(markdownBacklogItems.slug));

          const bounded = rows.slice(0, 20);
          const payload = {
            workspace: ctx.workspace.slug,
            total: rows.length,
            items: bounded.map((r) => ({
              id: r.id,
              kind: r.kind,
              slug: r.slug,
              planSlug: r.planSlug,
              epicSlug: r.epicSlug,
              title: r.title,
              status: r.status,
              priority: r.priority,
              repoPath: r.repoPath,
              link: `${ctx.workspace.slug}/${r.planSlug}${r.epicSlug ? `/${r.epicSlug}` : ""}/${r.slug}`,
              updatedAt: r.updatedAt.toISOString(),
            })),
          };
          return JSON.stringify(payload);
        },
      });

      const historyMessages = (input.messages ?? []).map((m) => ({
        role: m.role as "user" | "assistant",
        content: m.content,
      }));

      // Merge prompt as final user message; system is separate
      const promptMessages = [
        ...historyMessages,
        { role: "user" as const, content: input.prompt },
      ];

      const system = [
        OPS_SYSTEM_PROMPT,
        `Current workspace: ${ctx.workspace.name} (${ctx.workspace.slug})`,
        `Workspace id: ${ctx.workspace.id}`,
      ].join("\n");

      const { text, toolCalls, steps } = await generateText({
        model: modelResult.model,
        system,
        messages: promptMessages,
        tools: {
          fleetStatus: fleetStatusTool,
          convoyGet: convoyGetTool,
          backlogListTree: backlogListTreeTool,
        },
        maxSteps: 3,
        temperature: 0.4,
        maxTokens: 1200,
      });

      const trimmed = text.trim();
      if (!trimmed) {
        throw new TRPCError({
          code: "INTERNAL_SERVER_ERROR",
          message: "Empty copilot response",
        });
      }

      return {
        text: trimmed,
        resolvedAlias: resolved.resolvedAlias,
        modelId: resolved.model.modelId,
        providerType: resolved.model.providerType,
        toolCalls: toolCalls ?? [],
        steps: steps?.length ?? 0,
      };
    }),
});

// Alias for file naming: brief says copilot.ts with opsCopilot.generateText
export const copilotRouter = opsCopilotRouter;