# Multi-stage build for the backend service. Mirrors platform/telegram/Dockerfile:
# a golang-alpine builder yields a static binary shipped on distroless nonroot.
#
# The dictionary DAWGs are baked in from the scrabble-dictionary release artifact
# (Stage 14) — the same set the Go CI downloads — and BACKEND_DICT_DIR points the
# binary at them. The published solver module is fetched directly from Gitea
# (GOPRIVATE), so the build stage needs git and network.
#
# Build from the repository root so go.work, go.work.sum, pkg/ and backend/ are all
# in the Docker context:
#   docker build -f backend/Dockerfile -t scrabble-backend .

# --- dictionary artifact -----------------------------------------------------
FROM alpine:3.20 AS dawg
ARG DICT_VERSION=v1.0.0
RUN apk add --no-cache curl tar
RUN mkdir -p /dawg \
 && curl -fsSL -o /tmp/dawg.tar.gz \
      "https://gitea.iliadenisov.ru/developer/scrabble-dictionary/releases/download/${DICT_VERSION}/scrabble-dawg-${DICT_VERSION}.tar.gz" \
 && tar xzf /tmp/dawg.tar.gz -C /dawg

# --- build -------------------------------------------------------------------
FROM golang:1.26.3-alpine AS build
WORKDIR /src
# git: the published solver module is fetched from Gitea directly (GOPRIVATE).
RUN apk add --no-cache git
ENV GOPRIVATE=gitea.iliadenisov.ru/*

COPY go.work go.work.sum ./
COPY pkg ./pkg
COPY backend ./backend

# Reduce the workspace to what the backend needs: backend + pkg. loadtest and the
# gateway replace it requires are not in this context, so drop both.
RUN go work edit -dropuse=./gateway -dropuse=./platform/telegram -dropuse=./loadtest -dropreplace=scrabble/gateway@v0.0.0
RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -o /out/backend ./backend/cmd/backend

# --- runtime -----------------------------------------------------------------
FROM gcr.io/distroless/static-debian12:nonroot
COPY --from=build /out/backend /usr/local/bin/backend
COPY --from=dawg /dawg /opt/dawg
ENV BACKEND_DICT_DIR=/opt/dawg
ENTRYPOINT ["/usr/local/bin/backend"]