package git

import (
	"io"
	"os"

	"gopkg.in/src-d/go-git.v3/core"
	"gopkg.in/src-d/go-git.v3/formats/packfile"

	. "gopkg.in/check.v1"
)

type SuiteCommit struct {
	repos map[string]*Repository
}

var _ = Suite(&SuiteCommit{})

// create the repositories of the fixtures
func (s *SuiteCommit) SetUpSuite(c *C) {
	fixtureRepos := [...]struct {
		url      string
		packfile string
	}{
		{"https://github.com/tyba/git-fixture.git", "formats/packfile/fixtures/git-fixture.ofs-delta"},
	}
	s.repos = make(map[string]*Repository, 0)
	for _, fixRepo := range fixtureRepos {
		s.repos[fixRepo.url] = NewPlainRepository()

		d, err := os.Open(fixRepo.packfile)
		c.Assert(err, IsNil)

		r := packfile.NewReader(d)
		r.Format = packfile.OFSDeltaFormat // TODO: how to know the format of a pack file ahead of time?

		_, err = r.Read(s.repos[fixRepo.url].Storage)
		c.Assert(err, IsNil)

		c.Assert(d.Close(), IsNil)
	}
}

var iterTests = []struct {
	repo    string   // the repo name in the test suite's map of fixtures
	commits []string // the commit hashes to iterate over in the test
}{
	{"https://github.com/tyba/git-fixture.git", []string{
		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
		"918c48b83bd081e863dbe1b80f8998f058cd8294",
		"af2d6a6954d532f8ffb47615169c8fdf9d383a1a",
		"1669dce138d9b841a518c64b10914d88f5e488ea",
		"35e85108805c84807bc66a02d91535e1e24b38b9",
		"b029517f6300c2da0f4b651b8642506cd6aaf45d",
		"a5b8b09e2f8fcb0bb99d3ccb0958157b40890d69",
		"b029517f6300c2da0f4b651b8642506cd6aaf45d", // Intentional duplicate
		"b8e471f58bcbca63b07bda20e428190409c2db47",
		"b029517f6300c2da0f4b651b8642506cd6aaf45d"}}, // Intentional duplicate
}

func (s *SuiteCommit) TestIterSlice(c *C) {
	for i, t := range iterTests {
		r := s.repos[t.repo]
		iter := NewCommitIter(r, core.NewObjectSliceIter(makeObjectSlice(t.commits, r.Storage)))
		s.checkIter(c, r, i, iter, t.commits)
	}
}

func (s *SuiteCommit) TestIterLookup(c *C) {
	for i, t := range iterTests {
		r := s.repos[t.repo]
		iter := NewCommitIter(r, core.NewObjectLookupIter(r.Storage, makeHashSlice(t.commits)))
		s.checkIter(c, r, i, iter, t.commits)
	}
}

func (s *SuiteCommit) checkIter(c *C, r *Repository, subtest int, iter *CommitIter, commits []string) {
	for k := 0; k < len(commits); k++ {
		commit, err := iter.Next()
		c.Assert(err, IsNil, Commentf("subtest %d, iter %d, err=%v", subtest, k, err))
		c.Assert(commit.Hash.String(), Equals, commits[k], Commentf("subtest %d, iter %d, hash=%v, expected=%s", subtest, k, commit.Hash.String(), commits[k]))
	}
	_, err := iter.Next()
	c.Assert(err, Equals, io.EOF)
}

func (s *SuiteCommit) TestIterSliceClose(c *C) {
	for i, t := range iterTests {
		r := s.repos[t.repo]
		iter := NewCommitIter(r, core.NewObjectSliceIter(makeObjectSlice(t.commits, r.Storage)))
		s.checkIterClose(c, i, iter)
	}
}

func (s *SuiteCommit) TestIterLookupClose(c *C) {
	for i, t := range iterTests {
		r := s.repos[t.repo]
		iter := NewCommitIter(r, core.NewObjectLookupIter(r.Storage, makeHashSlice(t.commits)))
		s.checkIterClose(c, i, iter)
	}
}

func (s *SuiteCommit) checkIterClose(c *C, subtest int, iter *CommitIter) {
	iter.Close()
	_, err := iter.Next()
	c.Assert(err, Equals, io.EOF, Commentf("subtest %d, close 1, err=%v", subtest, err))

	iter.Close()
	_, err = iter.Next()
	c.Assert(err, Equals, io.EOF, Commentf("subtest %d, close 2, err=%v", subtest, err))
}

var fileTests = []struct {
	repo     string // the repo name as in localRepos
	commit   string // the commit to search for the file
	path     string // the path of the file to find
	blobHash string // expected hash of the returned file
	found    bool   // expected found value
}{
	// use git ls-tree commit to get the hash of the blobs
	{"https://github.com/tyba/git-fixture.git", "b029517f6300c2da0f4b651b8642506cd6aaf45d", "not-found",
		"", false},
	{"https://github.com/tyba/git-fixture.git", "b029517f6300c2da0f4b651b8642506cd6aaf45d", ".gitignore",
		"32858aad3c383ed1ff0a0f9bdf231d54a00c9e88", true},
	{"https://github.com/tyba/git-fixture.git", "b029517f6300c2da0f4b651b8642506cd6aaf45d", "LICENSE",
		"c192bd6a24ea1ab01d78686e417c8bdc7c3d197f", true},

	{"https://github.com/tyba/git-fixture.git", "6ecf0ef2c2dffb796033e5a02219af86ec6584e5", "not-found",
		"", false},
	{"https://github.com/tyba/git-fixture.git", "6ecf0ef2c2dffb796033e5a02219af86ec6584e5", ".gitignore",
		"32858aad3c383ed1ff0a0f9bdf231d54a00c9e88", true},
	{"https://github.com/tyba/git-fixture.git", "6ecf0ef2c2dffb796033e5a02219af86ec6584e5", "binary.jpg",
		"d5c0f4ab811897cadf03aec358ae60d21f91c50d", true},
	{"https://github.com/tyba/git-fixture.git", "6ecf0ef2c2dffb796033e5a02219af86ec6584e5", "LICENSE",
		"c192bd6a24ea1ab01d78686e417c8bdc7c3d197f", true},

	{"https://github.com/tyba/git-fixture.git", "35e85108805c84807bc66a02d91535e1e24b38b9", "binary.jpg",
		"d5c0f4ab811897cadf03aec358ae60d21f91c50d", true},
	{"https://github.com/tyba/git-fixture.git", "b029517f6300c2da0f4b651b8642506cd6aaf45d", "binary.jpg",
		"", false},

	{"https://github.com/tyba/git-fixture.git", "6ecf0ef2c2dffb796033e5a02219af86ec6584e5", "CHANGELOG",
		"d3ff53e0564a9f87d8e84b6e28e5060e517008aa", true},
	{"https://github.com/tyba/git-fixture.git", "1669dce138d9b841a518c64b10914d88f5e488ea", "CHANGELOG",
		"d3ff53e0564a9f87d8e84b6e28e5060e517008aa", true},
	{"https://github.com/tyba/git-fixture.git", "a5b8b09e2f8fcb0bb99d3ccb0958157b40890d69", "CHANGELOG",
		"d3ff53e0564a9f87d8e84b6e28e5060e517008aa", true},
	{"https://github.com/tyba/git-fixture.git", "35e85108805c84807bc66a02d91535e1e24b38b9", "CHANGELOG",
		"d3ff53e0564a9f87d8e84b6e28e5060e517008aa", false},
	{"https://github.com/tyba/git-fixture.git", "b8e471f58bcbca63b07bda20e428190409c2db47", "CHANGELOG",
		"d3ff53e0564a9f87d8e84b6e28e5060e517008aa", true},
	{"https://github.com/tyba/git-fixture.git", "b029517f6300c2da0f4b651b8642506cd6aaf45d", "CHANGELOG",
		"d3ff53e0564a9f87d8e84b6e28e5060e517008aa", false},
}

func (s *SuiteCommit) TestFile(c *C) {
	for i, t := range fileTests {
		commit, err := s.repos[t.repo].Commit(core.NewHash(t.commit))
		c.Assert(err, IsNil, Commentf("subtest %d: %v (%s)", i, err, t.commit))

		file, err := commit.File(t.path)
		found := err == nil
		c.Assert(found, Equals, t.found, Commentf("subtest %d, path=%s, commit=%s", i, t.path, t.commit))
		if found {
			c.Assert(file.Hash.String(), Equals, t.blobHash, Commentf("subtest %d, commit=%s, path=%s", i, t.commit, t.path))
		}
	}
}

func makeObjectSlice(hashes []string, storage core.ObjectStorage) []core.Object {
	series := make([]core.Object, 0, len(hashes))
	for _, member := range hashes {
		obj, err := storage.Get(core.NewHash(member))
		if err == nil {
			series = append(series, obj)
		}
	}
	return series
}

func makeHashSlice(hashes []string) []core.Hash {
	series := make([]core.Hash, 0, len(hashes))
	for _, member := range hashes {
		series = append(series, core.NewHash(member))
	}
	return series
}