import {
  type Actor,
  GROUP_MEMBER_MAX,
  GROUP_MEMBER_MIN,
  type Group,
  type GroupMember,
  type ProjectSession,
  type RunStatus,
  type SpaceGroup,
} from "@rakazo/contracts";
import { ACTIVE_RUN_STATUSES } from "@rakazo/core";
import { cancelRunsInTransaction } from "./cancel-runs.js";
import type { Prisma, PrismaClient } from "./client.js";
import { expireComputerExecutionLeases } from "./computers.js";
import { IsolationError } from "./scope.js";
import { lockSpaceForContentCreation } from "./spaces.js";
import { activeRunSelection, activeRunStatuses, previewFromBlocks } from "./thread-listing.js";

type GroupRecord = {
  id: string;
  spaceId: string;
  userId: string;
  name: string;
  pinned: boolean;
  sectionId: string | null;
  archivedAt: Date | null;
  createdAt: Date;
  updatedAt: Date;
  thread: {
    id: string;
    unread: boolean;
    messages: Array<{ blocks: unknown }>;
  } | null;
  members: Array<{
    bot: {
      id: string;
      name: string;
      color: string;
      runs: Array<{ status: string }>;
    };
  }>;
};

type SpaceGroupRecord = Pick<
  GroupRecord,
  "id" | "spaceId" | "name" | "pinned" | "sectionId" | "updatedAt" | "members"
> & {
  thread: {
    unread: boolean;
    messages: Array<{ blocks: unknown }>;
  } | null;
};

function mapGroupMembers(members: GroupRecord["members"]): GroupMember[] {
  return members.map((member) => ({
    botId: member.bot.id,
    name: member.bot.name,
    color: member.bot.color,
    status: member.bot.runs[0]?.status ?? "idle",
  }));
}

function mapGroup(group: GroupRecord): Group {
  if (!group.thread) throw new IsolationError("Group is missing its thread");
  const preview = previewFromBlocks(group.thread.messages[0]?.blocks);
  return {
    id: group.id,
    spaceId: group.spaceId,
    name: group.name,
    pinned: group.pinned,
    sectionId: group.sectionId,
    archivedAt: group.archivedAt?.toISOString() ?? null,
    members: mapGroupMembers(group.members),
    threadId: group.thread.id,
    preview,
    unread: group.thread.unread,
    updatedAt: group.updatedAt.toISOString(),
    createdAt: group.createdAt.toISOString(),
  };
}

function promptSnippet(text: string, max = 120): string {
  const oneLine = text.replace(/\s+/g, " ").trim();
  if (oneLine.length <= max) return oneLine;
  return `${oneLine.slice(0, max - 1)}…`;
}

function sessionStatusFromRuns(runs: Array<{ status: string }>): RunStatus {
  if (runs.some((run) => (ACTIVE_RUN_STATUSES as readonly string[]).includes(run.status))) {
    if (runs.some((run) => run.status === "waiting_input")) return "waiting_input";
    if (runs.some((run) => run.status === "waiting_takeover")) return "waiting_takeover";
    if (runs.some((run) => run.status === "failed")) return "failed";
    return "running";
  }
  if (runs.some((run) => run.status === "failed")) return "failed";
  if (runs.some((run) => run.status === "cancelled")) return "cancelled";
  return "completed";
}

function mapSpaceGroup(group: SpaceGroupRecord): SpaceGroup {
  if (!group.thread) throw new IsolationError("Group is missing its thread");
  return {
    id: group.id,
    spaceId: group.spaceId,
    name: group.name,
    pinned: group.pinned,
    sectionId: group.sectionId,
    members: mapGroupMembers(group.members),
    preview: previewFromBlocks(group.thread.messages[0]?.blocks),
    unread: group.thread.unread,
    updatedAt: group.updatedAt.toISOString(),
  };
}

function hasMinimumActiveMembers(members: readonly unknown[]) {
  return members.length >= GROUP_MEMBER_MIN;
}

async function assertOwnedBots(
  prisma: PrismaClient,
  actor: Actor,
  botIds: string[],
): Promise<GroupMember[]> {
  const unique = [...new Set(botIds)];
  if (unique.length < GROUP_MEMBER_MIN || unique.length > GROUP_MEMBER_MAX) {
    throw new IsolationError(
      `Groups require ${GROUP_MEMBER_MIN} to ${GROUP_MEMBER_MAX} distinct bots`,
    );
  }
  const bots = await prisma.bot.findMany({
    where: {
      id: { in: unique },
      spaceId: actor.spaceId,
      userId: actor.userId,
      archivedAt: null,
    },
    select: { id: true, name: true, color: true },
  });
  if (bots.length !== unique.length) throw new IsolationError();
  const botsById = new Map(bots.map((bot) => [bot.id, bot]));
  return unique.map((botId) => {
    const bot = botsById.get(botId);
    if (!bot) throw new IsolationError();
    return { botId: bot.id, name: bot.name, color: bot.color };
  });
}

const groupInclude = {
  thread: {
    include: {
      messages: { orderBy: { seq: "desc" as const }, take: 1 },
    },
  },
  members: {
    where: { bot: { archivedAt: null } },
    include: {
      bot: {
        select: {
          id: true,
          name: true,
          color: true,
          runs: activeRunSelection,
        },
      },
    },
    orderBy: { createdAt: "asc" as const },
  },
} as const;

const groupTargetInclude = {
  thread: { select: { id: true } },
  members: {
    where: { bot: { archivedAt: null } },
    include: {
      bot: {
        select: {
          id: true,
          name: true,
          color: true,
          runs: activeRunSelection,
        },
      },
    },
    orderBy: { createdAt: "asc" as const },
  },
} as const;

export function createGroupRepos(prisma: PrismaClient) {
  async function listSpaceGroupsForSpaces(actor: Actor, spaceIds: string[]): Promise<SpaceGroup[]> {
    if (spaceIds.length === 0) return [];
    const groups = await prisma.chatGroup.findMany({
      where: {
        spaceId: { in: spaceIds },
        userId: actor.userId,
        archivedAt: null,
      },
      select: {
        id: true,
        spaceId: true,
        name: true,
        pinned: true,
        sectionId: true,
        updatedAt: true,
        thread: {
          select: {
            unread: true,
            messages: {
              orderBy: { seq: "desc" },
              take: 1,
              select: { blocks: true },
            },
          },
        },
        members: groupInclude.members,
      },
      orderBy: [{ pinned: "desc" }, { updatedAt: "desc" }],
    });
    return groups
      .filter((group) => hasMinimumActiveMembers(group.members))
      .map((group) => mapSpaceGroup(group));
  }

  return {
    async listGroups(actor: Actor, options: { archived?: boolean } = {}): Promise<Group[]> {
      const groups = await prisma.chatGroup.findMany({
        where: {
          spaceId: actor.spaceId,
          userId: actor.userId,
          archivedAt: options.archived ? { not: null } : null,
        },
        include: groupInclude,
        orderBy: [{ pinned: "desc" }, { updatedAt: "desc" }],
      });
      return groups
        .filter((group) => hasMinimumActiveMembers(group.members))
        .map((group) => mapGroup(group as GroupRecord));
    },

    listSpaceGroupsForSpaces,

    async getGroup(actor: Actor, groupId: string, options: { includeArchived?: boolean } = {}) {
      const group = await prisma.chatGroup.findFirst({
        where: {
          id: groupId,
          spaceId: actor.spaceId,
          userId: actor.userId,
          ...(options.includeArchived ? {} : { archivedAt: null }),
        },
        include: groupInclude,
      });
      if (!group || !hasMinimumActiveMembers(group.members)) throw new IsolationError();
      return group as GroupRecord;
    },

    async getGroupTarget(actor: Actor, groupId: string) {
      const group = await prisma.chatGroup.findFirst({
        where: {
          id: groupId,
          spaceId: actor.spaceId,
          userId: actor.userId,
          archivedAt: null,
        },
        include: groupTargetInclude,
      });
      if (!group || !hasMinimumActiveMembers(group.members)) throw new IsolationError();
      return group;
    },

    async createGroup(actor: Actor, input: { name: string; botIds: string[] }): Promise<Group> {
      const members = await assertOwnedBots(prisma, actor, input.botIds);
      const created = await prisma.$transaction(async (tx) => {
        await lockSpaceForContentCreation(tx, {
          spaceId: actor.spaceId,
          userId: actor.userId,
        });
        const group = await tx.chatGroup.create({
          data: {
            spaceId: actor.spaceId,
            userId: actor.userId,
            name: input.name.trim(),
          },
        });
        await tx.chatGroupMember.createMany({
          data: members.map((member) => ({ groupId: group.id, botId: member.botId })),
        });
        await tx.thread.create({
          data: {
            spaceId: actor.spaceId,
            groupId: group.id,
            userId: actor.userId,
          },
        });
        return tx.chatGroup.findFirstOrThrow({
          where: { id: group.id },
          include: groupInclude,
        });
      });
      return mapGroup(created as GroupRecord);
    },

    async updateGroup(
      actor: Actor,
      input: {
        groupId: string;
        name?: string;
        botIds?: string[];
        pinned?: boolean;
        sectionId?: string | null;
      },
    ): Promise<{ group: Group; cancelledRunIds: string[] }> {
      const members = input.botIds ? await assertOwnedBots(prisma, actor, input.botIds) : undefined;
      const updated = await prisma.$transaction(async (tx) => {
        await lockOwnedGroup(tx, actor, input.groupId);
        const current = await tx.chatGroup.findFirst({
          where: {
            id: input.groupId,
            spaceId: actor.spaceId,
            userId: actor.userId,
            archivedAt: null,
          },
          include: {
            members: { select: { botId: true, bot: { select: { archivedAt: true } } } },
            thread: { select: { id: true } },
          },
        });
        if (!current?.thread) throw new IsolationError();
        if (
          !members &&
          !hasMinimumActiveMembers(
            current.members.filter((member) => member.bot.archivedAt === null),
          )
        ) {
          throw new IsolationError();
        }
        const nextBotIds = new Set(
          members?.map((member) => member.botId) ?? current.members.map((member) => member.botId),
        );
        const removedBotIds = current.members
          .map((member) => member.botId)
          .filter((botId) => !nextBotIds.has(botId));
        const activeRuns = removedBotIds.length
          ? await tx.run.findMany({
              where: {
                threadId: current.thread.id,
                botId: { in: removedBotIds },
                status: {
                  in: ["queued", "leased", "running", "waiting_input", "waiting_takeover"],
                },
              },
              select: { id: true, taskId: true },
            })
          : [];
        if (activeRuns.length) {
          const now = new Date();
          await cancelRunsInTransaction(tx, activeRuns, now);
        }
        if (input.name !== undefined) {
          await tx.chatGroup.update({
            where: { id: input.groupId },
            data: { name: input.name.trim() },
          });
        }
        if (members) {
          await tx.chatGroupMember.deleteMany({ where: { groupId: input.groupId } });
          await tx.chatGroupMember.createMany({
            data: members.map((member) => ({ groupId: input.groupId, botId: member.botId })),
          });
        }
        await tx.chatGroup.update({
          where: { id: input.groupId },
          data: {
            updatedAt: new Date(),
            pinned: input.pinned,
            sectionId: input.sectionId,
          },
        });
        return tx.chatGroup
          .findFirstOrThrow({
            where: { id: input.groupId },
            include: groupInclude,
          })
          .then((group) => ({ group, cancelledRunIds: activeRuns.map((run) => run.id) }));
      });
      if (!updated.group.thread) throw new IsolationError();
      return {
        group: mapGroup(updated.group as GroupRecord),
        cancelledRunIds: updated.cancelledRunIds,
      };
    },

    async archiveGroup(actor: Actor, groupId: string) {
      return prisma.$transaction(async (tx) => {
        await lockOwnedGroup(tx, actor, groupId);
        const current = await tx.chatGroup.findFirst({
          where: {
            id: groupId,
            spaceId: actor.spaceId,
            userId: actor.userId,
            archivedAt: null,
          },
          select: { thread: { select: { id: true } } },
        });
        if (!current?.thread) throw new IsolationError();

        const activeRuns = await tx.run.findMany({
          where: {
            threadId: current.thread.id,
            status: { in: activeRunStatuses },
          },
          select: { id: true, taskId: true },
        });
        const runIds = activeRuns.map((run) => run.id);
        const now = new Date();
        const computers = runIds.length
          ? await tx.computer.findMany({
              where: { executionRunId: { in: runIds } },
              select: {
                id: true,
                homeKey: true,
                kind: true,
                providerRef: true,
                executionBotId: true,
                executionRunId: true,
              },
            })
          : [];
        const leases = runIds.length
          ? await tx.computerExecutionLease.findMany({
              where: { runId: { in: runIds } },
              select: { computerId: true, runId: true, fence: true },
            })
          : [];
        const leaseByComputerId = new Map(leases.map((lease) => [lease.computerId, lease]));
        const computersWithLease = computers.map((computer) => ({
          ...computer,
          executionFence: leaseByComputerId.get(computer.id)?.fence ?? 0,
        }));

        if (runIds.length) {
          await cancelRunsInTransaction(tx, activeRuns, now);
          await expireComputerExecutionLeases(tx, { runId: { in: runIds } });
          await tx.computer.updateMany({
            where: { executionRunId: { in: runIds } },
            data: {
              executionRunId: null,
              executionBotId: null,
              executionLeaseExpiresAt: null,
            },
          });
          await tx.event.deleteMany({
            where: { type: "thread.progress", runId: { in: runIds } },
          });
        }

        await tx.chatGroup.update({
          where: { id: groupId },
          data: { archivedAt: now, pinned: false },
        });

        return { cancelledRunIds: runIds, computers: computersWithLease };
      });
    },

    async restoreGroup(actor: Actor, groupId: string) {
      const restored = await prisma.chatGroup.updateMany({
        where: { id: groupId, spaceId: actor.spaceId, userId: actor.userId },
        data: { archivedAt: null },
      });
      if (restored.count !== 1) throw new IsolationError();
    },

    async removeGroup(actor: Actor, groupId: string) {
      return prisma.$transaction(async (tx) => {
        await lockOwnedGroup(tx, actor, groupId);
        const group = await tx.chatGroup.findUnique({
          where: { id: groupId },
          select: {
            artifacts: { select: { storageKey: true } },
            members: { orderBy: { createdAt: "asc" }, take: 1, select: { botId: true } },
          },
        });
        const contextBotId = group?.members[0]?.botId;
        if (!contextBotId) throw new IsolationError();
        await tx.chatGroup.delete({ where: { id: groupId } });
        return {
          contextBotId,
          artifactStorageKeys: group.artifacts.map((artifact) => artifact.storageKey),
        };
      });
    },

    async listSessions(actor: Actor, groupId: string): Promise<ProjectSession[]> {
      const group = await prisma.chatGroup.findFirst({
        where: {
          id: groupId,
          spaceId: actor.spaceId,
          userId: actor.userId,
          archivedAt: null,
        },
        select: { thread: { select: { id: true } } },
      });
      if (!group?.thread) throw new IsolationError();
      const messages = await prisma.message.findMany({
        where: { threadId: group.thread.id, role: "user" },
        orderBy: { seq: "desc" },
        take: 50,
        select: {
          id: true,
          blocks: true,
          createdAt: true,
          sourceRuns: {
            select: {
              status: true,
              bot: { select: { name: true } },
            },
          },
        },
      });
      return messages.map((message) => ({
        sessionId: message.id,
        sourceMessageId: message.id,
        promptSnippet: promptSnippet(previewFromBlocks(message.blocks) || "Neue Unterhaltung"),
        startedAt: message.createdAt.toISOString(),
        status: sessionStatusFromRuns(message.sourceRuns),
        botNames: [...new Set(message.sourceRuns.map((run) => run.bot.name))],
      }));
    },

    mapGroup,
  };
}

export async function lockOwnedGroup(
  prisma: Pick<Prisma.TransactionClient, "$queryRaw">,
  actor: Pick<Actor, "spaceId" | "userId">,
  groupId: string,
) {
  const locked = await prisma.$queryRaw<Array<{ id: string }>>`
    SELECT id
    FROM chat_groups
    WHERE id = ${groupId}
      AND "spaceId" = ${actor.spaceId}
      AND "userId" = ${actor.userId}
    FOR UPDATE
  `;
  if (locked.length !== 1) throw new IsolationError();
}

export async function touchGroupUpdatedAt(
  prisma: Pick<Prisma.TransactionClient, "chatGroup">,
  groupId: string,
) {
  await prisma.chatGroup.update({
    where: { id: groupId },
    data: { updatedAt: new Date() },
  });
}