package main

// The merge preview of a fetch (novox/hq ADR 0484 clause 3; issue 1676), as build_go_fetch answers it. The merge itself
// is the SDK's (buildstep.MergeInto), the one every build module's fetch step makes.

import (
	"context"

	"git.novox.be/novox/mesh-sdk/go/buildstep"
	"git.novox.be/novox/mesh-sdk/go/forgekey"
)

// remote is the address a repository is fetched from: the forge over ssh as the account, or RemoteBase when a test set it.
func (m *Module) remote(repository string) string {
	base := m.RemoteBase
	if base == "" {
		base = "ssh://" + ForgeAlias + "/"
	}
	return base + repository + ".git"
}

// merge makes the merge preview of the head onto base and writes the answer into res.
func (m *Module) merge(ctx context.Context, run forgekey.Runner, res *FetchResult, tree, remote, base, commit string) error {
	mr, err := buildstep.MergeInto(ctx, run, tree, remote, base, commit, m.FetchOptions...)
	if err != nil {
		return err
	}
	res.Base = mr.Base
	res.Conflicts, res.Merge, res.Changed = mr.Conflicts, mr.Merge, mr.Changed
	if mr.Merge != "" {
		res.Programs = &mr.Programs
	}
	if res.Merge == "" {
		return nil
	}
	res.Trees, err = buildstep.ModuleTrees(ctx, m.Run, m.baseEnv(), tree, res.Merge)
	return err
}