# Build stage — pinned to the build host's arch so cross-compilation
# via GOOS/GOARCH is fast and avoids QEMU emulation of the toolchain.
FROM --platform=$BUILDPLATFORM golang:1.25-alpine AS builder

# Platform args populated by buildx for each target in a multi-platform build.
ARG TARGETOS
ARG TARGETARCH

# Build arguments
ARG VERSION=dev
ARG GIT_COMMIT=unknown
ARG BUILD_TIME=unknown
ARG BUILD_FLAGS="-s -w"

# Install build dependencies including protoc
RUN apk add --no-cache git make protobuf protobuf-dev

# Set working directory
WORKDIR /build

# Copy go mod files
COPY go.mod go.sum ./

# Download dependencies
RUN go mod download

# Install protoc plugins
RUN go install google.golang.org/protobuf/cmd/protoc-gen-go@latest && \
    go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

# Copy source code
COPY . .

# Generate protobuf code
RUN make proto-gen

# Build binary with version information, cross-compiling to the target arch.
RUN CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} go build -a -installsuffix cgo \
    -ldflags "-X main.Version=${VERSION} -X main.GitCommit=${GIT_COMMIT} -X main.BuildTime=${BUILD_TIME} ${BUILD_FLAGS}" \
    -o server ./cmd/server

# Runtime stage
FROM alpine:3.21

# Install runtime dependencies
RUN apk --no-cache add ca-certificates tzdata

# Create non-root user
RUN addgroup -g 1000 notifier && \
    adduser -D -u 1000 -G notifier notifier

# Set working directory
WORKDIR /app

# Copy binary from builder
COPY --from=builder /build/server /app/

# Copy default config (can be overridden with volume mount)
COPY config.yaml /app/config.yaml

# Create directory for queue persistence
RUN mkdir -p /var/lib/notifier && \
    chown -R notifier:notifier /var/lib/notifier

# Change to non-root user
USER notifier

# Expose ports
EXPOSE 8080 50051 9090 8081

# Run server (defaults to both REST and gRPC)
# Override mode with environment variable: -e NOTIFIER_SERVER_MODE=rest or -e NOTIFIER_SERVER_MODE=grpc
CMD ["/app/server"]