package main

import (
	"fmt"
	"path/filepath"
	"slices"

	"go.wit.com/lib/protobuf/gitpb"
	"go.wit.com/log"
)

var ErrorReposHasLocalBranches error = fmt.Errorf("repo still has local branches")
var ErrorMergeBranch error = fmt.Errorf("trunk has things not in the branch")
var ErrorMergeTrunk error = fmt.Errorf("branch has things not in trunk")

func doClean() error {
	if argv.Clean.Devel != nil {
		if err := doCleanDevel(); err != nil {
			badExit(err)
		}
		log.Info("finished attempt at cleaning devel branches")
		return nil
	}
	if argv.Clean.User != nil {
		if err := doCleanUser(); err != nil {
			log.Info(err)
			okExit("")
		}
		return nil
	}
	return nil
}

func doCleanUser() error {
	if _, count, _, err := IsEverythingOnMaster(); err != nil {
		if count == 0 {
			log.Info("No repos are on the master branch")
			return nil
		}
		log.Info("Not all repos are on the master branch")
		// return err
	}

	all := me.forge.Repos.SortByFullPath()
	for all.Scan() {
		repo := all.Next()
		if err := doCleanUserRepo(repo); err != nil {
			log.Info(repo.GetGoPath(), err)
			return err
		}
	}
	return nil
}

func doCleanDevel() error {
	var total int
	var count int
	all := me.forge.Repos.SortByFullPath()
	for all.Scan() {
		repo := all.Next()
		if argv.Verbose {
			// log.Info("Cleaning:", repo.GetGoPath())
		}
		total += 1
		if repo.GetCurrentBranchName() != repo.GetDevelBranchName() {
			// only process branches in devel
			// return nil
		}
		if repo.IsDirty() {
			return nil
		}
		count += 1
		if err := doCleanDevelRepo(repo); err != nil {
			log.Info(repo.GetGoPath(), err)
			return err
		}
	}
	log.Printf("attempted cleaning %d branches of %d total branches\n", count, total)
	return nil
}

func exactDevelRepo(repo *gitpb.Repo) error {
	devel := repo.GetDevelBranchName()
	master := repo.GetMasterBranchName()
	err := isBranchSubsetOfTrunk(repo, devel, master)
	if err != nil {
		return err
	}
	return nil
}

func checkhashes(repo *gitpb.Repo, hashes []string, refpath string) ([]string, error) {
	if !repo.Exists(refpath) {
		return hashes, nil
	}
	r, err := repo.RunStrictNew([]string{"cat", refpath})
	if err != nil {
		return hashes, err
	}
	newhash := r.Stdout[0]
	for _, hash := range hashes {
		if newhash != hash {
			return hashes, fmt.Errorf("%s hash broke %s %s", repo.GetGoPath(), newhash, hash)
		}
	}
	hashes = append(hashes, newhash)
	return hashes, nil
}

func doCleanDevelRepo(repo *gitpb.Repo) error {
	var hashes []string
	devel := repo.GetDevelBranchName()
	// log.Printf("%s Start verify devel branch: %s\n", repo.GetGoPath(), devel)

	// check if devel branch exists in remote repo
	if repo.Exists(filepath.Join(".git/refs/remotes/origin", devel)) {
		if argv.Verbose {
			var err error
			if hashes, err = checkhashes(repo, hashes, filepath.Join(".git/refs/remotes/origin", devel)); err != nil {
				return err
			}
		}
		remote := filepath.Join("origin", devel)
		if err := isBranchSubsetOfTrunk(repo, devel, remote); err != nil {
			if err == ErrorMergeBranch {
				log.Info("can not do this yet. need push to upstream", repo.GetGoPath())
				if argv.Force {
					return nil
				}
				return err
			}
			return err
		}
		// log.Info("todo: verify against remote devel branch", repo.GetGoPath())
	}

	// verify devel branch is subset of master branch
	master := repo.GetMasterBranchName()
	if argv.Verbose {
		var err error
		if hashes, err = checkhashes(repo, hashes, filepath.Join(".git/refs/heads", devel)); err != nil {
			return err
		}
	}
	if argv.Verbose {
		var err error
		if hashes, err = checkhashes(repo, hashes, filepath.Join(".git/refs/heads", devel)); err != nil {
			return err
		}
	}
	if argv.Verbose {
		log.Info("repo hashes all match. incredible", hashes, repo.GetGoPath())
	}
	if err := isBranchSubsetOfTrunk(repo, devel, master); err != nil {
		if err == ErrorMergeBranch {
			if argv.Force {
				if repo.GetCurrentBranchName() == devel {
					cmd := []string{"git", "merge", master}
					// only run this if branch is local
					_, err := repo.RunVerbose(cmd)
					return err
				} else {
					cmd := []string{"git", "merge", master}
					log.Info("can't run. on wrong branch.", cmd, repo.GetGoPath(), "current branch =", repo.GetCurrentBranchName())
				}
				return nil
			}
			return err
		}
		return err
	}
	// log.Info("todo: verify against remote devel branch", repo.GetGoPath())

	return nil
}

// removes all local branches
func doCleanUserRepo(repo *gitpb.Repo) error {
	var hasLocal bool
	if repo.GitConfig == nil {
		return fmt.Errorf("GitConfig == nil")
	}
	if repo.GetCurrentBranchName() != repo.GetMasterBranchName() {
		// skip this while in devel
		return nil
	}
	if repo.IsDirty() {
		return nil
	}

	for _, l := range repo.GitConfig.Local {
		log.Info("\tlocal branch name:", l.Name)
	}
	if argv.Clean.User != nil {
		base := repo.GetUserBranchName()
		if repo.Exists(filepath.Join(".git/refs/heads", base)) {
			log.Info("Delete local branch:", base, repo.GetGoPath())
			err := forceDeleteUserBranch(repo, base)
			repo.Reload()
			if err != nil {
				log.Info("Delete local branch ERROR:", err)
				return err
			}
			// return fmt.Errorf("todo")
		}
		return nil
	}

	for name, b := range repo.GitConfig.Branches {
		if b.Name == "" {
			b.Name = name
		}
		if name == repo.GetMasterBranchName() {
			// never delete the master branch
			// todo: make sure the master branch is in sync with remote master
			continue
		}
		if name == repo.GetUserBranchName() {
			hasLocal = true
			if err := doCleanUserBranch(repo, b); err != nil {
				log.Info("\tLOCAL BRANCH ERROR user =", name)
				return err
			}
			log.Info("\tLOCAL BRANCH user =", name)
			continue
		}
		if name == repo.GetDevelBranchName() {
			continue
		}
		if name == repo.GetMasterBranchName() {
			continue
		}
		if err := verifyLocalBranchIsMerged(repo, b); err != nil {
			return err
		}
	}
	if argv.Clean.Force == nil {
		if hasLocal {
			return ErrorReposHasLocalBranches
		}
	}
	return nil
}

func verifyLocalBranchIsMerged(repo *gitpb.Repo, branch *gitpb.GitBranch) error {
	base := filepath.Base(branch.Name)
	log.Info("local branch name unknown:", base, branch.Name, branch.Merge, branch.Remote, repo.GetGoPath())

	// check if it exists in the origin
	if repo.Exists(filepath.Join(".git/refs/remotes/origin", base)) {
		err := fmt.Errorf("repo %s ERROR. branch is also remote %s", repo.GetGoPath(), branch.Name)
		log.Info(err)
		if err := isSafeToDelete(repo, base); err != nil {
			log.Info(err)
			return err
		}
		if err := requiresGitPush(repo, base); err != nil {
			log.Info(err)
			return err
		}
		err = fmt.Errorf("repo %s BRANCH AND REMOTE CAN BE DELETED %s", repo.GetGoPath(), branch.Name)
		log.Info(err)
		if argv.Clean.Force != nil {
			err = BADforceDeleteBranch(repo, base)
			repo.Reload()
		}
		return err
	}

	if !repo.Exists(filepath.Join(".git/refs/heads", base)) {
		log.Info("GitConfig() parse logic error. not really a local branch", base)
		me.forge.Repos.Delete(repo)
		configSave = true
		return nil
	}

	// this is only a local branch
	if err := isSafeToDelete(repo, base); err != nil {
		log.Info(err)
		return err
	}
	err := fmt.Errorf("repo %s BRANCH CAN PROBABLY BE DELETED base=%s fullname=%s", repo.GetGoPath(), base, branch.Name)
	log.Info(err)
	if argv.Clean.Force != nil {
		err = BADforceDeleteBranch(repo, base)
		repo.Reload()
	}
	return err
}

func doCleanUserBranch(repo *gitpb.Repo, branch *gitpb.GitBranch) error {
	if branch.Name != repo.GetUserBranchName() {
		return fmt.Errorf("repo %s was not user branch %s", repo.GetGoPath(), branch.Name)
	}
	/*
		if bran == repo.GetUserBranchName() {
			log.Info("The user branch also has a remote branch", repo.CurrentTag.Refname)
			log.Info("TODO: verify the remote branch is out of date", repo.CurrentTag.Refname)
			log.Info("TODO: delete the remote branch", repo.CurrentTag.Refname)
			return nil
		}
	*/

	if !repo.Exists(filepath.Join(".git/refs/heads", branch.Name)) {
		err := fmt.Errorf("BAD FORGE LOGIC. DELETE REPO %s", repo.GetGoPath())
		log.Warn(err)
		me.forge.Repos.Repos = slices.DeleteFunc(me.forge.Repos.Repos, func(r *gitpb.Repo) bool {
			if repo.GetGoPath() == r.GetGoPath() {
				return true
			}
			return false
		})

		// me.forge.Repos.Delete(repo)
		me.forge.ConfigSave()
		// os.Exit(0)
		return nil
	}

	if repo.Exists(filepath.Join(".git/refs/remotes/origin", branch.Name)) {
		log.Info("why is this non-localonly branch a problem?", branch.Name)
		repo.RunVerbose([]string{"ls", "-l", ".git/refs/remotes/origin"})
		repo.RunVerbose([]string{"cat", filepath.Join(".git/refs/remotes/origin", branch.Name)})
		repo.RunVerbose([]string{"cat", filepath.Join(".git/refs/heads", branch.Name)})
		if err := userToDevelRequiresGitPush(repo, branch.Name); err != nil {
			log.Info(err)
			log.Info("THIS USER BRANCH MUST BE PUSHED TO DEVEL", branch.Name)
			return err
		}
		log.Info("THIS USER BRANCH IS CLEAN TO DELETE", branch.Name)
		if argv.Clean.Force != nil {
			err := BADforceDeleteBranch(repo, branch.Name)
			repo.Reload()
			if err != nil {
				return err
			}
		}
	} else {
		log.Info("why is this local only branch a problem?", branch.Name)
		repo.RunVerbose([]string{"ls", "-l", ".git/refs/remotes/origin"})
		r, err := repo.RunVerbose([]string{"cat", filepath.Join(".git/refs/heads", branch.Name)})
		if err == nil {
			cmd := []string{"git", "show", "-s", "--format=\"%H %ae %as %s\"", r.Stdout[0]}
			repo.RunVerbose(cmd)
			log.Info(cmd)
		}
		if err := userToDevelRequiresGitPush(repo, branch.Name); err != nil {
			log.Info(err)
			log.Info("THIS USER BRANCH MUST BE PUSHED TO DEVEL", branch.Name)
			return err
		}
		log.Info("THIS USER BRANCH IS CLEAN TO DELETE", branch.Name)
		if argv.Clean.Force != nil {
			cmd := []string{"git", "branch", "-D", branch.Name}
			if _, err := repo.RunVerbose(cmd); err != nil {
				log.Info("THE GIT BRANCH DELETE ERROR IS:", err)
				return err
			}
			return nil
		}
	}
	// return fmt.Errorf("%s repo.CurrentTag is not local: %s. Don't proceed yet", repo.GetGoPath(), repo.CurrentTag.Refname)
	log.Printf("Do something %s on branch name:%s merge:%s remote:%s\n", repo.GetGoPath(), branch.Name, branch.Merge, branch.Remote)
	return nil
}

func userToDevelRequiresGitPush(repo *gitpb.Repo, branchName string) error {
	devel := repo.GetDevelBranchName()
	missing := countDiffObjects(repo, branchName, "origin/"+devel)
	b2 := countDiffObjects(repo, "origin/"+devel, branchName)
	log.Info("user vs devel count", missing, b2)
	if missing == 0 && b2 == 0 {
		return nil
	}
	if missing != 0 {
		log.Info("user vs devel count missing != 0, b2 ==", missing, b2)
		log.Info("THIS MEANS THE LOCAL BRANCH NEEDS GIT PUSH TO ORIGIN BRANCH ==", missing)
		// if argv.Examine.Fix != nil {
		// 	return gitPushStrict(repo, branchName)
		// }
		return fmt.Errorf("user branch not clean to delete %d %d", missing, b2)
	}
	if missing == 0 {
		// log.Info("THIS MEANS THE LOCAL BRANCH IS OK TO DELETE missing =", missing)
		log.Info("THIS IS REALLY BAD RIGHT NOW. must to git push / git merge missing =", missing, b2)
	}
	return fmt.Errorf("user branch not clean to delete. maybe it is? devel might be ahead of user branch. %d %d", missing, b2)
}

// checks against upstream master
func isSafeToDelete(repo *gitpb.Repo, old string) error {
	var head string
	head = filepath.Join("origin", repo.GetMasterBranchName())

	if !repo.Exists(filepath.Join(".git/refs/remotes/", head)) {
		head = filepath.Join("origin", "HEAD")
	}

	b1 := countDiffObjects(repo, old, head)
	b2 := countDiffObjects(repo, head, old)
	log.Info(old, "vs origin count", b1, b2)
	if b1 == 0 && b2 == 0 {
		log.Info("isSafeToDelete() SAFE TO DELETE ==", old, b1, head, b2)
		return nil
	}
	if b1 == 0 {
		log.Info("isSafeToDelete() SAFE TO DELETE ==", old, b1, head, b2)
		return nil
	}
	if b1 != 0 {
		log.Info(old, "vs", head, " count b1 != 0, b2 ==", b2, "b1 =", b1)
		log.Info("THIS MEANS THE LOCAL BRANCH NEEDS GIT PUSH TO ORIGIN BRANCH ==", b1)
		cmd := repo.ConstructGitDiffLog(old, head)
		log.Info("cmd", cmd)
		cmd = repo.ConstructGitDiffLog(head, old)
		log.Info("cmd", cmd)
		if argv.Clean.Force != nil {
			// return gitPushStrict(repo, branchName)
		}
		return fmt.Errorf("user branch not clean to delete. needs git push %d %d", b1, b2)
	}
	return fmt.Errorf("user branch not clean to delete. needs git push %d %d", b1, b2)
}

// literally ignore all errors. delete everthing with no checks for now
func forceDeleteUserBranch(repo *gitpb.Repo, branch string) error {
	if repo.IsDirty() {
		log.Info(repo.GetGoPath(), "is dirty")
		return nil
	}
	if repo.GetUserBranchName() != branch {
		log.Info(repo.GetGoPath(), branch, "is not the user branch", repo.GetUserBranchName())
		return nil
	}
	if err := isSafeToDelete(repo, branch); err != nil {
		log.Info(err)
		return err
	}
	if repo.Exists(filepath.Join(".git/refs/remotes/origin/", branch)) {
		if err := requiresGitPush(repo, branch); err != nil {
			log.Info(err)
			return err
		}
	}
	configSave = true

	cmd := []string{"git", "branch", "-D", branch}
	if _, err := repo.RunVerbose(cmd); err != nil {
		log.Info("THE GIT BRANCH DELETE ERROR IS:", err)
		// return err
	}
	log.Info("THIS USER REMOTE BRANCH MUST BE DELETED HERE", branch)
	if repo.Exists(filepath.Join(".git/refs/remote/origin", branch)) {
		// git push origin --delete jcarr
		cmd = []string{"git", "push", "origin", "--delete", branch}
		if _, err := repo.RunVerbose(cmd); err != nil {
			log.Info("THE GIT BRANCH DELETE ERROR IS:", err)
			// return err
		}
	}
	cmd = []string{"git", "branch", "-D", "--remote", "origin/" + branch}
	if _, err := repo.RunVerbose(cmd); err != nil {
		log.Info("THE GIT BRANCH DELETE ERROR IS:", err)
		// return err
	}
	// return fmt.Errorf("one at a time %s", repo.GetGoPath())
	return nil
}

// literally ignore all errors. delete everthing with no checks for now
func BADforceDeleteBranch(repo *gitpb.Repo, branch string) error {
	if repo.IsDirty() {
		log.Info(repo.GetGoPath(), "is dirty")
		return nil
	}
	configSave = true

	cmd := []string{"git", "branch", "-D", branch}
	if _, err := repo.RunVerbose(cmd); err != nil {
		log.Info("THE GIT BRANCH DELETE ERROR IS:", err)
		// return err
	}
	log.Info("THIS USER REMOTE BRANCH MUST BE DELETED HERE", branch)
	if repo.Exists(filepath.Join(".git/refs/remote/origin", branch)) {
		// git push origin --delete jcarr
		cmd = []string{"git", "push", "origin", "--delete", branch}
		if _, err := repo.RunVerbose(cmd); err != nil {
			log.Info("THE GIT BRANCH DELETE ERROR IS:", err)
			// return err
		}
	}
	cmd = []string{"git", "branch", "-D", "--remote", "origin/" + branch}
	if _, err := repo.RunVerbose(cmd); err != nil {
		log.Info("THE GIT BRANCH DELETE ERROR IS:", err)
		// return err
	}
	// return fmt.Errorf("one at a time %s", repo.GetGoPath())
	return nil
}

// verifies that the branch is a pure subset of the other branch
// sorry about the 'master' 'slave' nameing thing. I guess that isn't
// 'cool' to use anymore. I can't think of other terms that aren't reserved words.
func isBranchSubsetOfTrunk(repo *gitpb.Repo, branch string, trunk string) error {
	b1 := countGitDiffLog(repo, branch, trunk) // should be zero
	b2 := countGitDiffLog(repo, trunk, branch) // can be greater than 1
	// log.Info(branch, "vs", trunk, "count", b1, b2)
	if b1 == 0 && b2 == 0 {
		// log.Info("branch and trunk are identical ==", branch, b1, trunk, b2)
		return nil
	}
	if argv.Verbose {
		log.Printf("%-40s NOT EXACT %s %s (%d) (%d)\n", repo.GetGoPath(), branch, trunk, b1, b2)
	}
	if b1 == 0 {
		cmd := []string{"git", "merge", trunk}
		log.Printf("%-40s branch %s needs merge with trunk %s len(%d) %s\n", repo.GetGoPath(), branch, trunk, b2, cmd)
		return ErrorMergeBranch
	}
	if b2 == 0 {
		log.Printf("%-40s trunk %s needs merge with branch %s len(%d)\n", repo.GetGoPath(), branch, trunk, b2)
		return ErrorMergeTrunk
	}
	return fmt.Errorf("branch not clean to delete. needs merge %d %d", b1, b2)
}

// count all objects only in branch1
// if zero, that means branch1 is entirely contained in branch2 and can be safely deleted
func countGitDiffLog(repo *gitpb.Repo, branch1, branch2 string) int {
	cmd := repo.ConstructGitDiffLog(branch1, branch2)
	r, err := repo.RunStrictNew(cmd)
	if err != nil {
		return -1
	}
	// log.Info("countDiffObjects()", cmd, len(r.Stdout), strings.Join(r.Stdout, " "))
	return len(r.Stdout)
}