import { TRPCError } from "@trpc/server";
import { z } from "zod";
import { and, asc, desc, eq } from "drizzle-orm";
import {
  formResponses,
  forms,
  objects,
  propertyDefinitions,
  propertyValues,
} from "@tasks/database/schema";
import { type Context, router, protectedProcedure } from "@/server/trpc";

const UUID_RE =
  /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

type FormFieldRow = {
  id: string;
  type?: string;
  mappedProperty?: string | null;
};

async function resolvePropertyDefId(
  db: Pick<Context["db"], "select">,
  workspaceId: string,
  mappedProperty: string,
): Promise<string | null> {
  if (UUID_RE.test(mappedProperty)) {
    const [def] = await db
      .select({ id: propertyDefinitions.id })
      .from(propertyDefinitions)
      .where(
        and(
          eq(propertyDefinitions.id, mappedProperty),
          eq(propertyDefinitions.workspaceId, workspaceId),
        ),
      )
      .limit(1);
    return def?.id ?? null;
  }

  const [def] = await db
    .select({ id: propertyDefinitions.id })
    .from(propertyDefinitions)
    .where(
      and(
        eq(propertyDefinitions.workspaceId, workspaceId),
        eq(propertyDefinitions.name, mappedProperty),
      ),
    )
    .limit(1);
  return def?.id ?? null;
}

export const formsRouter = router({
  list: protectedProcedure
    .input(z.object({ workspaceId: z.string().uuid() }))
    .query(async ({ ctx, input }) => {
      const rows = await ctx.db
        .select()
        .from(forms)
        .where(eq(forms.workspaceId, input.workspaceId))
        .orderBy(desc(forms.updatedAt), asc(forms.id));

      return { forms: rows };
    }),

  getById: protectedProcedure
    .input(z.object({ id: z.string().uuid() }))
    .query(async ({ ctx, input }) => {
      const row = await ctx.db.query.forms.findFirst({
        where: eq(forms.id, input.id),
      });

      if (!row) {
        throw new TRPCError({ code: "NOT_FOUND", message: "Form not found" });
      }

      return row;
    }),

  create: protectedProcedure
    .input(
      z.object({
        workspaceId: z.string().uuid(),
        title: z.string().min(1).max(500),
        description: z.string().optional(),
        coverImage: z.string().optional(),
        objectId: z.string().uuid().nullable().optional(),
        targetType: z.string().max(50).optional().default("task"),
        fields: z.array(z.unknown()).optional().default([]),
        settings: z.record(z.unknown()).optional().default({}),
        isPublished: z.boolean().optional().default(false),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const userId = ctx.session.user.id;
      if (!userId) {
        throw new TRPCError({
          code: "UNAUTHORIZED",
          message: "Missing user id",
        });
      }

      const now = new Date();
      const [created] = await ctx.db
        .insert(forms)
        .values({
          workspaceId: input.workspaceId,
          title: input.title,
          description: input.description ?? null,
          coverImage: input.coverImage ?? null,
          objectId: input.objectId ?? null,
          targetType: input.targetType ?? "task",
          fields: input.fields ?? [],
          settings: input.settings ?? {},
          isPublished: input.isPublished ?? false,
          createdBy: userId,
          createdAt: now,
          updatedAt: now,
        })
        .returning();

      if (!created) {
        throw new TRPCError({
          code: "INTERNAL_SERVER_ERROR",
          message: "Failed to create form",
        });
      }

      return created;
    }),

  update: protectedProcedure
    .input(
      z.object({
        id: z.string().uuid(),
        title: z.string().min(1).max(500).optional(),
        description: z.string().nullable().optional(),
        coverImage: z.string().nullable().optional(),
        objectId: z.string().uuid().nullable().optional(),
        targetType: z.string().max(50).optional(),
        fields: z.array(z.unknown()).optional(),
        settings: z.record(z.unknown()).optional(),
        isPublished: z.boolean().optional(),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const { id, ...patch } = input;
      const now = new Date();

      const [updated] = await ctx.db
        .update(forms)
        .set({
          ...(patch.title !== undefined ? { title: patch.title } : {}),
          ...(patch.description !== undefined ? { description: patch.description } : {}),
          ...(patch.coverImage !== undefined ? { coverImage: patch.coverImage } : {}),
          ...(patch.objectId !== undefined ? { objectId: patch.objectId } : {}),
          ...(patch.targetType !== undefined ? { targetType: patch.targetType } : {}),
          ...(patch.fields !== undefined ? { fields: patch.fields } : {}),
          ...(patch.settings !== undefined ? { settings: patch.settings } : {}),
          ...(patch.isPublished !== undefined ? { isPublished: patch.isPublished } : {}),
          updatedAt: now,
        })
        .where(eq(forms.id, id))
        .returning();

      if (!updated) {
        throw new TRPCError({ code: "NOT_FOUND", message: "Form not found" });
      }

      return updated;
    }),

  delete: protectedProcedure
    .input(z.object({ id: z.string().uuid() }))
    .mutation(async ({ ctx, input }) => {
      const deleted = await ctx.db
        .delete(forms)
        .where(eq(forms.id, input.id))
        .returning({ id: forms.id });

      if (deleted.length === 0) {
        throw new TRPCError({ code: "NOT_FOUND", message: "Form not found" });
      }
    }),

  submit: protectedProcedure
    .input(
      z.object({
        formId: z.string().uuid(),
        data: z.record(z.unknown()),
      }),
    )
    .mutation(async ({ ctx, input }) => {
      const userId = ctx.session.user.id;
      if (!userId) {
        throw new TRPCError({
          code: "UNAUTHORIZED",
          message: "Missing user id",
        });
      }

      const form = await ctx.db.query.forms.findFirst({
        where: eq(forms.id, input.formId),
      });

      if (!form) {
        throw new TRPCError({ code: "NOT_FOUND", message: "Form not found" });
      }

      const fieldRows = Array.isArray(form.fields) ? (form.fields as FormFieldRow[]) : [];
      const workspaceId = form.workspaceId;

      let title = form.title;
      let description: string | null | undefined;
      let icon: string | null | undefined;
      let status: string | null | undefined;

      for (const field of fieldRows) {
        const key = field.id;
        if (!key || !(key in input.data)) continue;
        const raw = input.data[key];
        const mapKey = field.mappedProperty?.trim();
        if (!mapKey) continue;

        const lower = mapKey.toLowerCase();
        if (lower === "title") {
          title = raw == null ? title : String(raw);
          continue;
        }
        if (lower === "description") {
          description = raw == null ? null : String(raw);
          continue;
        }
        if (lower === "icon") {
          icon = raw == null ? null : String(raw);
          continue;
        }
        if (lower === "status") {
          status = raw == null ? null : String(raw);
          continue;
        }
      }

      const now = new Date();

      const result = await ctx.db.transaction(async (tx) => {
        const [createdObject] = await tx
          .insert(objects)
          .values({
            type: form.targetType,
            title,
            parentId: form.objectId ?? null,
            workspaceId,
            ...(description !== undefined ? { description } : {}),
            ...(icon !== undefined ? { icon } : {}),
            ...(status !== undefined ? { status } : {}),
            createdBy: userId,
            createdAt: now,
            updatedAt: now,
          })
          .returning();

        if (!createdObject) {
          throw new TRPCError({
            code: "INTERNAL_SERVER_ERROR",
            message: "Failed to create object from form",
          });
        }

        for (const field of fieldRows) {
          const key = field.id;
          if (!key || !(key in input.data)) continue;

          const skipTypes = new Set(["section_header", "divider"]);
          if (field.type && skipTypes.has(field.type)) continue;

          const mapKey = field.mappedProperty?.trim();
          if (!mapKey) continue;

          const lower = mapKey.toLowerCase();
          if (["title", "description", "icon", "status"].includes(lower)) {
            continue;
          }

          const propertyDefId = await resolvePropertyDefId(tx, workspaceId, mapKey);
          if (!propertyDefId) continue;

          const value = input.data[key];

          await tx
            .insert(propertyValues)
            .values({
              objectId: createdObject.id,
              propertyDefId,
              value: value as unknown,
              createdAt: now,
              updatedAt: now,
            })
            .onConflictDoUpdate({
              target: [propertyValues.objectId, propertyValues.propertyDefId],
              set: {
                value: value as unknown,
                updatedAt: now,
              },
            });
        }

        const [responseRow] = await tx
          .insert(formResponses)
          .values({
            formId: form.id,
            respondentId: userId,
            createdObjectId: createdObject.id,
            data: input.data,
            submittedAt: now,
          })
          .returning();

        if (!responseRow) {
          throw new TRPCError({
            code: "INTERNAL_SERVER_ERROR",
            message: "Failed to record form response",
          });
        }

        return { object: createdObject, response: responseRow };
      });

      return result;
    }),

  listResponses: protectedProcedure
    .input(
      z.object({
        formId: z.string().uuid(),
        limit: z.number().int().positive().max(500).optional(),
        offset: z.number().int().nonnegative().optional(),
      }),
    )
    .query(async ({ ctx, input }) => {
      const limit = input.limit ?? 50;
      const offset = input.offset ?? 0;

      const form = await ctx.db.query.forms.findFirst({
        where: eq(forms.id, input.formId),
        columns: { id: true },
      });

      if (!form) {
        throw new TRPCError({ code: "NOT_FOUND", message: "Form not found" });
      }

      const rows = await ctx.db
        .select()
        .from(formResponses)
        .where(eq(formResponses.formId, input.formId))
        .orderBy(desc(formResponses.submittedAt), asc(formResponses.id))
        .limit(limit)
        .offset(offset);

      return { responses: rows };
    }),
});