// Package forge talks to the code host a repo lives on, Gitea or GitHub, through one [Forge] interface, so spx
// commands work the same on either.
package forge

import "strings"

// Kind names a forge flavor.
type Kind string

const (
	KindGitea  Kind = "gitea"
	KindGitHub Kind = "github"
)

// KindForHost tells which forge serves `host`: only `github.com` is GitHub, every other host is taken as Gitea.
func KindForHost(host string) Kind {
	if strings.EqualFold(host, "github.com") {
		return KindGitHub
	}
	return KindGitea
}

// Issue is the part of an issue spx reads; its JSON form is what `spx issue view --json` prints.
type Issue struct {
	Number    int      `json:"number"`
	Title     string   `json:"title"`
	Body      string   `json:"body"`
	State     string   `json:"state"`
	Author    string   `json:"author"`
	Assignees []string `json:"assignees"`
	HTMLURL   string   `json:"html_url"`
}

// Comment is one comment on an issue or pull request.
type Comment struct {
	ID        int64  `json:"id"`
	Author    string `json:"author"`
	Body      string `json:"body"`
	CreatedAt string `json:"created_at"`
	HTMLURL   string `json:"html_url"`
}

// BranchRef is one side of a pull request: the branch and the commit it pointed at.
type BranchRef struct {
	Branch string `json:"branch"`
	SHA    string `json:"sha"`
}

// PullRequest is the part of a pull request spx reads; its JSON form is what `spx pr view --json` prints.
type PullRequest struct {
	Number  int       `json:"number"`
	Title   string    `json:"title"`
	Body    string    `json:"body"`
	State   string    `json:"state"`
	Merged  bool      `json:"merged"`
	Author  string    `json:"author"`
	Head    BranchRef `json:"head"`
	Base    BranchRef `json:"base"`
	HTMLURL string    `json:"html_url"`
}

// NewPullRequest is what it takes to open a pull request from branch `Head` into branch `Base`.
type NewPullRequest struct {
	Title string
	Body  string
	Head  string
	Base  string
}

// Forge is one repo on a code host, with the few calls spx makes against it.
//
// Pull requests share numbering with issues on both forges, so the issue and comment calls also work on a pull
// request number; that is how pull request comments are read and posted.
type Forge interface {
	// Kind tells which forge this is.
	Kind() Kind
	// CurrentUserLogin returns the login of the user the token belongs to.
	CurrentUserLogin() (string, error)
	// CreateIssue opens an issue assigned to `assignees`.
	CreateIssue(title, body string, assignees []string) (*Issue, error)
	GetIssue(number int) (*Issue, error)
	UpdateIssueBody(number int, body string) error
	// ListIssueComments returns every comment, oldest first, reading all pages.
	ListIssueComments(number int) ([]Comment, error)
	CreateIssueComment(number int, body string) (*Comment, error)
	GetPullRequest(number int) (*PullRequest, error)
	CreatePullRequest(pr NewPullRequest) (*PullRequest, error)
	// DefaultBranch returns the repo's default branch, the usual base of a new pull request.
	DefaultBranch() (string, error)
}