import type { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
import { z } from "zod";
import { isPrincipalContext, requirePermission } from "../auth/authorization.js";
import {
  CatalogLogicalRelationshipService,
  LogicalRelationshipColumnNotFoundError,
  LogicalRelationshipDatabaseNotFoundError,
  LogicalRelationshipDuplicateError,
  LogicalRelationshipNotFoundError,
  LogicalRelationshipReadOnlyError,
  LogicalRelationshipSchemaStaleError,
  LogicalRelationshipTargetNotUniqueError,
  LogicalRelationshipTypeIncompatibleError,
} from "../catalog/logical-relationship-service.js";
import type { CatalogOperationCoordinator } from "../catalog/operation-coordinator.js";
import { CatalogOperationInProgressError, CatalogUnavailableError } from "../catalog/types.js";

const idSchema = z.uuid();
const createSchema = z.object({
  sourceColumnId: idSchema,
  targetColumnId: idSchema,
}).strict();
const statusSchema = z.object({ status: z.enum(["active", "excluded"]) }).strict();
const emptySchema = z.object({}).strict();

function manage(request: FastifyRequest, reply: FastifyReply) {
  return isPrincipalContext(requirePermission(request, reply, "database.manage"));
}

function safeError(reply: FastifyReply, error: unknown) {
  if (error instanceof CatalogUnavailableError) {
    return reply.code(503).send({ code: "catalog_unavailable", message: "Database catalog is unavailable." });
  }
  if (error instanceof CatalogOperationInProgressError) {
    return reply.code(409).send({
      code: "database_operation_in_progress",
      message: "A database operation is already in progress.",
    });
  }
  if (error instanceof LogicalRelationshipDatabaseNotFoundError) {
    return reply.code(404).send({ code: "database_not_found", message: "Database configuration was not found." });
  }
  if (error instanceof LogicalRelationshipColumnNotFoundError) {
    return reply.code(404).send({
      code: "column_not_found",
      message: "Catalog column was not found.",
      field: error.field,
    });
  }
  if (error instanceof LogicalRelationshipNotFoundError) {
    return reply.code(404).send({ code: "relationship_not_found", message: "Relationship was not found." });
  }
  if (error instanceof LogicalRelationshipDuplicateError) {
    return reply.code(409).send({ code: "relationship_duplicate", message: "Relationship already exists." });
  }
  if (error instanceof LogicalRelationshipReadOnlyError) {
    return reply.code(409).send({ code: "relationship_read_only", message: "Physical relationships are read-only." });
  }
  if (error instanceof LogicalRelationshipSchemaStaleError) {
    return reply.code(409).send({
      code: "relationship_schema_stale",
      message: "Synchronize the current database schema before managing logical relationships.",
    });
  }
  if (error instanceof LogicalRelationshipTargetNotUniqueError) {
    return reply.code(422).send({
      code: "relationship_target_not_unique",
      message: "Target column must be the only primary-key column of its table.",
      field: "targetColumnId",
    });
  }
  if (error instanceof LogicalRelationshipTypeIncompatibleError) {
    return reply.code(422).send({
      code: "relationship_type_incompatible",
      message: "Source and target column types are incompatible.",
      field: "targetColumnId",
    });
  }
  if (error instanceof z.ZodError) {
    return reply.code(400).send({
      code: "relationship_request_invalid",
      message: "Relationship request is invalid.",
    });
  }
  return reply.code(500).send({
    code: "relationship_operation_failed",
    message: "Relationship operation failed.",
  });
}

export function catalogLogicalRelationshipRoutes(
  app: FastifyInstance,
  deps: {
    service: CatalogLogicalRelationshipService;
    operations: CatalogOperationCoordinator;
  },
): void {
  app.get("/catalog/databases/:databaseId/relationships", async (request, reply) => {
    if (!manage(request, reply)) return reply;
    try {
      const databaseId = idSchema.parse((request.params as { databaseId?: unknown }).databaseId);
      return await deps.service.list(databaseId);
    } catch (error) { return safeError(reply, error); }
  });

  app.post("/catalog/databases/:databaseId/relationships", async (request, reply) => {
    if (!manage(request, reply)) return reply;
    try {
      const databaseId = idSchema.parse((request.params as { databaseId?: unknown }).databaseId);
      const input = createSchema.parse(request.body);
      const relationship = await deps.operations.run(databaseId, async () => (
        await deps.service.addManual(databaseId, input.sourceColumnId, input.targetColumnId)
      ));
      return reply.code(201).send(relationship);
    } catch (error) { return safeError(reply, error); }
  });

  app.post("/catalog/databases/:databaseId/relationships/rebuild-generated", async (request, reply) => {
    if (!manage(request, reply)) return reply;
    try {
      const databaseId = idSchema.parse((request.params as { databaseId?: unknown }).databaseId);
      emptySchema.parse(request.body ?? {});
      return await deps.operations.run(databaseId, async () => (
        await deps.service.rebuildGenerated(databaseId)
      ));
    } catch (error) { return safeError(reply, error); }
  });

  app.patch("/catalog/databases/:databaseId/relationships/:relationshipId", async (request, reply) => {
    if (!manage(request, reply)) return reply;
    try {
      const params = request.params as { databaseId?: unknown; relationshipId?: unknown };
      const databaseId = idSchema.parse(params.databaseId);
      const relationshipId = idSchema.parse(params.relationshipId);
      const input = statusSchema.parse(request.body);
      return await deps.operations.run(databaseId, async () => (
        await deps.service.setStatus(databaseId, relationshipId, input.status)
      ));
    } catch (error) { return safeError(reply, error); }
  });

  app.delete("/catalog/databases/:databaseId/relationships/:relationshipId", async (request, reply) => {
    if (!manage(request, reply)) return reply;
    try {
      const params = request.params as { databaseId?: unknown; relationshipId?: unknown };
      const databaseId = idSchema.parse(params.databaseId);
      const relationshipId = idSchema.parse(params.relationshipId);
      await deps.operations.run(databaseId, async () => {
        await deps.service.deletePermanently(databaseId, relationshipId);
      });
      return reply.code(204).send();
    } catch (error) { return safeError(reply, error); }
  });
}