package main

import (
	"bufio"
	"errors"
	"slices"
	"strings"

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

type PRInfo struct {
	pr      *models.PullRequest
}

type PRSet struct {
	prs    []PRInfo
	config *common.AutogitConfig
}

func readPRData(gitea common.GiteaPRFetcher, org, repo string, num int64, currentSet []PRInfo) ([]PRInfo, error) {
	for _, p := range currentSet {
		if num == p.pr.Index && repo == p.pr.Base.Repo.Name && org == p.pr.Base.Repo.Owner.UserName {
			return nil, nil
		}
	}

	pr, err := gitea.GetPullRequest(org, repo, num)
	if err != nil {
		return nil, err
	}
	_, refPRs := common.ExtractDescriptionAndPRs(bufio.NewScanner(strings.NewReader(pr.Body)))

	retSet := []PRInfo{PRInfo{pr: pr}}

	for _, prdata := range refPRs {
		data, err := readPRData(gitea, prdata.Org, prdata.Repo, prdata.Num, slices.Concat(currentSet, retSet))
		if err != nil {
			return nil, err
		}
		retSet = slices.Concat(retSet, data)
	}

	return retSet, nil
}

func FetchPRSet(gitea common.GiteaPRFetcher, org, repo string, num int64, config *common.AutogitConfig) (*PRSet, error) {
	prs, err := readPRData(gitea, org, repo, num, nil)
	if err != nil {
		return nil, err
	}

	return &PRSet{prs: prs, config: config}, nil
}

func (rs *PRSet) GetPrjGitPR() (*models.PullRequest, error) {
	var ret *models.PullRequest

	for _, prinfo := range rs.prs {
		if prinfo.pr.Base.Repo.Name == rs.config.GitProjectName && prinfo.pr.Base.Repo.Owner.UserName == rs.config.Organization {
			if ret == nil {
				ret = prinfo.pr
			} else {
				return nil, errors.New("Multiple PrjGit PRs in one review set")
			}
		}
	}

	if ret != nil {
		return ret, nil
	}

	return nil, errors.New("No PrjGit PR found")
}

func (rs *PRSet) IsConsistent() bool {
	prjpr, err := rs.GetPrjGitPR()
	if err != nil {
		return false
	}
	_, prjpr_set := common.ExtractDescriptionAndPRs(bufio.NewScanner(strings.NewReader(prjpr.Body)))
	if len(prjpr_set) != len(rs.prs)-1 { // 1 to many mapping
		return false
	}

	for _, prinfo := range rs.prs {
		if prjpr == prinfo.pr {
			continue
		}
		_, prs := common.ExtractDescriptionAndPRs(bufio.NewScanner(strings.NewReader(prinfo.pr.Body)))
		if len(prs) != 1 || prs[0].Repo != prjpr.Base.Repo.Name || prs[0].Org != prjpr.Base.Repo.Owner.UserName || prs[0].Num != prjpr.Index {
			return false
		}
	}
	return true
}

func (rs *PRSet) IsReviewed() bool {
	return false
}