package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"strings"

	"src.opensuse.org/autogits/common"
	"src.opensuse.org/autogits/common/gitea-generated/models"
)

//go:generate mockgen -source=maintainership.go -destination=mock/maintainership.go -typed

const ProjectKey = ""

type MaintainershipMap map[string][]string

func parseMaintainershipData(data []byte) (MaintainershipMap, error) {
	maintainers := make(MaintainershipMap)
	if err := json.Unmarshal(data, &maintainers); err != nil {
		return nil, err
	}

	return maintainers, nil
}

func ProjectMaintainershipData(gitea common.GiteaMaintainershipInterface, org, prjGit, branch string) (MaintainershipMap, error) {
	data, err := gitea.FetchMaintainershipFile(org, prjGit, branch)
	if err != nil || data == nil {
		return nil, err
	}

	return parseMaintainershipData(data)
}

func MaintainerListForProject(maintainers MaintainershipMap) []string {
	m, found := maintainers[ProjectKey]
	if !found {
		return nil
	}

	return m
}

func MaintainerListForPackage(maintainers MaintainershipMap, pkg string) []string {
	pkgMaintainers := maintainers[pkg]
	prjMaintainers := maintainers[ProjectKey]

prjMaintainer:
	for _, prjm := range prjMaintainers {
		for i := range pkgMaintainers {
			if pkgMaintainers[i] == prjm {
				continue prjMaintainer
			}
		}
		pkgMaintainers = append(pkgMaintainers, prjm)
	}

	return pkgMaintainers
}

type PRReviewInfo struct {
	pr      *models.PullRequest
	reviews []*models.PullReview
}

func fetchAllAssociatedPRs(gitea GiteaPRInterface, org, repo string, prNum int64) ([]PRReviewInfo, error) {
	pr, reviews, err := gitea.GetPullRequestAndReviews(org, repo, prNum)
	if err != nil {
		return nil, err
	}

	ret := make([]PRReviewInfo, 1, 2)
	ret[0].pr = pr
	ret[0].reviews = reviews

	return ret, nil
}

func CheckIfMaintainersApproved(gitea common.GiteaMaintainershipInterface, giteapr GiteaPRInterface, config common.AutogitConfig, prjGitPRNumber int64) (bool, error) {
	prs, _ := fetchAllAssociatedPRs(giteapr, config.Organization, config.GitProjectName, prjGitPRNumber)
	data, _ := gitea.FetchMaintainershipFile(config.Organization, config.GitProjectName, config.Branch)

	for _, pr := range prs {
		_, associatedPRs := common.ExtractPRsFromDescription(bufio.NewScanner(strings.NewReader(pr.pr.Body)))

		if len(associatedPRs) == 0 {
			// no associated packages with this PR
			break
		}

		if len(associatedPRs) != 1 {
			return false, fmt.Errorf("Associated PR doesn't link only to the prjgit PR: %s/%s#%d",
				associatedPRs[0].Org, associatedPRs[0].Repo, associatedPRs[0].Num)

		}

		if associatedPRs[0].Org != config.Organization || associatedPRs[0].Repo != config.GitProjectName || associatedPRs[0].Num != prjGitPRNumber {
			return false, fmt.Errorf("Associated PR (%s/%s#%d) not linking back to prj PR (%s/%s#%d)", 
				associatedPRs[0].Org, associatedPRs[0].Repo, associatedPRs[0].Num,
				config.Organization, config.GitProjectName, prjGitPRNumber)
		}
	}

	parseMaintainershipData(data)

	return false, nil
}