package check

import (
	"fmt"
	"strings"
)

// A change that adds or modifies a compiled program fails (issue 1577): it is build output, `go build` in a module's folder
// writes one beside go.mod, and `git add -A` takes it. The build module's fetch step, which holds the merged clone, reads the
// first bytes of each changed file and reports the programs (mesh-sdk buildstep.MergeInto); the checker judges the answer.

// NoProgramsReported is the warning of a build module whose fetch answered no programs field: an older module, which cannot
// tell, so the check does not refuse a program it did not look for.
const NoProgramsReported = "the build module did not report programs: a compiled program in the change is not refused"

// checkBinariesOf fails a pull request whose change adds or modifies a compiled program, naming each file. It judges the
// first fetch answer of the pull request, whichever build module gave it; a build module that reports no programs leaves a
// warning on the check and passes it.
func (st *state) checkBinariesOf(t *target) verdictPtr {
	key := fmt.Sprintf("%s#%d", t.pull.Repository, t.pull.Number)
	if t.fetched.Merge == "" {
		return nil // no merge was made: nothing was changed to judge
	}
	if t.fetched.Programs == nil {
		st.c.note(fmt.Sprintf("%s: %s (%s)", key, NoProgramsReported, t.module))
		st.c.warn(key, fmt.Sprintf("a compiled program is not refused: %s reported no programs", t.module))
		st.j.logf("%s: %s (%s)", key, NoProgramsReported, t.module)
		return nil
	}
	var found []string
	for _, p := range *t.fetched.Programs {
		if p.Commit != "" {
			found = append(found, fmt.Sprintf("%s: a compiled program added in %s and removed later: it stays in history; squash the branch (issue 1577)", p.Path, short12(p.Commit)))
			continue
		}
		found = append(found, p.Path+": a compiled program is build output: remove it and add it to .gitignore (issue 1577)")
	}
	if len(found) > 0 {
		return failed(t.node, fmt.Sprintf("%s: %s", key, strings.Join(found, "; ")))
	}
	return nil
}