package main

import (
	"fmt"
	"github.com/KatolaZ/git2go"
	"golang.org/x/crypto/openpgp"
	"log"
	"os"
	"strings"
	//	"log"
)

func CommitToString(commit *git.Commit) string {

	var ret string

	ret += fmt.Sprintf("type: %s\n", commit.Type())
	ret += fmt.Sprintf("Id: %s\n", commit.Id())
	ret += fmt.Sprintf("Author: %s\n", commit.Author())
	ret += fmt.Sprintf("Message: %s\n", commit.Message())
	ret += fmt.Sprintf("Parent-count: %d\n", commit.ParentCount())

	return ret
}

// FIXME: RETURN THE ENTITY PROVIDED BY THE CHECK, OR nil
func check_signature(commit *git.Commit, keys *map[string]openpgp.KeyRing) (signature, signed string, err error) {

	signature, signed, err = commit.ExtractSignature()

	if err == nil {
		for _, keyring := range *keys {

			_, err_sig :=
				openpgp.CheckArmoredDetachedSignature(keyring, strings.NewReader(signed),
					strings.NewReader(signature))

			if err_sig == nil {
				fmt.Printf("Good signature \n")
				return signature, signed, nil
			}
			err = err_sig
		}
	}

	return "", "", err
}

func find_scorsh_message(commit *git.Commit) (string, error) {

	msg := commit.RawMessage()
	debug.log("[find_scorsg_msg] found message:\n %s\n", msg)

	return msg, nil
}

// traverse all the commits between two references, looking for scorsh
// commands
// fixme: we don't have just one keyring here....
func walk_commits(msg SCORSHmsg, w *SCORSHworker) error {

	fmt.Printf("Inside parse_commits\n")

	reponame := msg.Repo
	old_rev := msg.Old_rev
	new_rev := msg.New_rev

	repo, err := git.OpenRepository(reponame)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error while opening repository %s (%s)\n",
			reponame, err)
		return SCORSHerr(SCORSH_ERR_NO_REPO)
	}

	old_rev_oid, err := git.NewOid(old_rev)

	oldrev_commit, err := repo.LookupCommit(old_rev_oid)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Commit: %s does not exist\n", old_rev)
		return SCORSHerr(SCORSH_ERR_NO_COMMIT)
	}

	new_rev_oid, err := git.NewOid(new_rev)

	newrev_commit, err := repo.LookupCommit(new_rev_oid)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Commit: %s does not exist\n", new_rev)
		return SCORSHerr(SCORSH_ERR_NO_COMMIT)
	}

	cur_commit := newrev_commit

	for cur_commit.Id().String() != oldrev_commit.Id().String() {

		commit, err := repo.LookupCommit(cur_commit.Id())
		if err == nil {

			fmt.Printf("%s", CommitToString(commit))
			// We should look for scorsh-tags, and if the commit has any,
			// check if it can be verified by any of the keyrings associated
			// with the scorsh-tag

			// check if the commit contains a scorsh command

			_, err = find_scorsh_message(commit)

			//signature, signed, err := check_signature(commit, &w.Keys)
			//_, _, err := check_signature(commit, w.keys)
			if err != nil {
				log.Printf("[worker: %s] %s\n", w.Name, SCORSHerr(SCORSH_ERR_SIGNATURE))
			} else {

			}
			cur_commit = commit.Parent(0)
		} else {
			fmt.Printf("Commit %x not found!\n", cur_commit.Id())
			return SCORSHerr(SCORSH_ERR_NO_COMMIT)
		}
	}
	return nil
}