# Production Dockerfile for Backend API
# Optimized for smaller size and security

# Build stage
FROM golang:1.23-alpine AS builder

WORKDIR /app

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

# Copy go mod files first for better caching
COPY go.mod go.sum ./

# Download dependencies (this layer will be cached if go.mod/go.sum don't change)
RUN go mod download

# Copy source code
COPY . .

# Build the application with optimizations
# - CGO_ENABLED=0: static binary, no C dependencies
# - -ldflags="-w -s": strip debug info and symbol table
# - -trimpath: remove file system paths from binaries
RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \
    -a -installsuffix cgo \
    -ldflags="-w -s -extldflags '-static'" \
    -trimpath \
    -o veza-api \
    ./cmd/api/main.go

# Runtime stage - minimal alpine
FROM alpine:3.21

# Install only runtime dependencies
RUN apk --no-cache add ca-certificates tzdata && \
    # Add wget for health checks
    apk --no-cache add wget && \
    # Clean up apk cache
    rm -rf /var/cache/apk/*

# Create non-root user for security
RUN addgroup -g 1001 -S app && \
    adduser -S app -u 1001 -G app -h /app -s /bin/sh

# Create app directory
WORKDIR /app

# Copy binary from builder
COPY --from=builder --chown=app:app /app/veza-api /app/veza-api

# Copy migrations if they exist (optional)
# Use RUN with conditional check to handle missing migrations directory gracefully
RUN --mount=from=builder,source=/app,target=/tmp/builder \
    if [ -d /tmp/builder/migrations ] && [ "$(ls -A /tmp/builder/migrations 2>/dev/null)" ]; then \
        cp -r /tmp/builder/migrations /app/migrations && \
        chown -R app:app /app/migrations; \
    fi

# Switch to non-root user
USER app

# Expose port
EXPOSE 8080

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
    CMD wget --no-verbose --tries=1 --spider http://localhost:8080/api/v1/health || exit 1

# Run the application
ENTRYPOINT ["./veza-api"]