package gitea_test

import (
	"context"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"testing"

	"git.d-ma.be/mathias/gitea-mcp/internal/gitea"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestCreateIssue(t *testing.T) {
	var captured []byte
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, "/api/v1/repos/o/r/issues", r.URL.Path)
		assert.Equal(t, http.MethodPost, r.Method)
		var err error
		captured, err = io.ReadAll(r.Body)
		require.NoError(t, err)
		w.WriteHeader(http.StatusCreated)
		_, _ = w.Write([]byte(`{"number":42,"title":"x","body":"y","html_url":"http://example.com/issues/42","state":"open"}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	iss, err := c.CreateIssue(context.Background(), "o", "r", gitea.CreateIssueArgs{
		Title: "x",
		Body:  "y",
	})
	require.NoError(t, err)

	var payload map[string]any
	require.NoError(t, json.Unmarshal(captured, &payload))
	assert.Equal(t, "x", payload["title"])
	assert.Equal(t, "y", payload["body"])

	assert.Equal(t, 42, iss.Number)
	assert.Equal(t, "x", iss.Title)
	assert.Equal(t, "y", iss.Body)
	assert.Equal(t, "http://example.com/issues/42", iss.HTMLURL)
	assert.Equal(t, "open", iss.State)
}

func TestGetIssue(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, http.MethodGet, r.Method)
		assert.Equal(t, "/api/v1/repos/o/r/issues/42", r.URL.Path)
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"number":42,"title":"fix auth","body":"details","state":"open","html_url":"http://example.com/issues/42","created_at":"2026-05-01T00:00:00Z","updated_at":"2026-05-02T00:00:00Z","comments":3}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	iss, err := c.GetIssue(context.Background(), "o", "r", 42)
	require.NoError(t, err)
	assert.Equal(t, 42, iss.Number)
	assert.Equal(t, "fix auth", iss.Title)
	assert.Equal(t, "open", iss.State)
	assert.Equal(t, 3, iss.Comments)
}

func TestGetIssue_NotFound(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusNotFound)
		_, _ = w.Write([]byte(`{"message":"issue not found"}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	_, err := c.GetIssue(context.Background(), "o", "r", 999)
	require.Error(t, err)
	assert.ErrorIs(t, err, gitea.ErrNotFound)
}

func TestEditIssue(t *testing.T) {
	var captured []byte
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, http.MethodPatch, r.Method)
		assert.Equal(t, "/api/v1/repos/o/r/issues/42", r.URL.Path)
		var err error
		captured, err = io.ReadAll(r.Body)
		require.NoError(t, err)
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"number":42,"title":"new title","body":"new body","state":"open","html_url":"http://example.com/issues/42"}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	title, body := "new title", "new body"
	iss, err := c.EditIssue(context.Background(), "o", "r", 42, gitea.EditIssueArgs{Title: &title, Body: &body})
	require.NoError(t, err)

	var payload map[string]any
	require.NoError(t, json.Unmarshal(captured, &payload))
	assert.Equal(t, "new title", payload["title"])
	assert.Equal(t, "new body", payload["body"])

	assert.Equal(t, 42, iss.Number)
	assert.Equal(t, "new title", iss.Title)
}

// EditIssue must send only the fields explicitly provided — an omitted field
// (nil pointer) is left untouched server-side.
func TestEditIssue_PartialPatchOmitsUnsetFields(t *testing.T) {
	var captured []byte
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var err error
		captured, err = io.ReadAll(r.Body)
		require.NoError(t, err)
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"number":42,"title":"only title","state":"open"}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	title := "only title"
	_, err := c.EditIssue(context.Background(), "o", "r", 42, gitea.EditIssueArgs{Title: &title})
	require.NoError(t, err)

	var payload map[string]any
	require.NoError(t, json.Unmarshal(captured, &payload))
	assert.Equal(t, "only title", payload["title"])
	_, hasBody := payload["body"]
	assert.False(t, hasBody, "body must be omitted when not set")
}

// An explicit empty-string body clears the field — pointer-to-"" is sent, not omitted.
func TestEditIssue_EmptyBodyIsSent(t *testing.T) {
	var captured []byte
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var err error
		captured, err = io.ReadAll(r.Body)
		require.NoError(t, err)
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"number":42,"body":"","state":"open"}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	body := ""
	_, err := c.EditIssue(context.Background(), "o", "r", 42, gitea.EditIssueArgs{Body: &body})
	require.NoError(t, err)

	var payload map[string]any
	require.NoError(t, json.Unmarshal(captured, &payload))
	val, hasBody := payload["body"]
	assert.True(t, hasBody, "explicit empty body must be sent so it can clear the field")
	assert.Equal(t, "", val)
}

func TestEditIssue_NotFound(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusNotFound)
		_, _ = w.Write([]byte(`{"message":"issue not found"}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	title := "x"
	_, err := c.EditIssue(context.Background(), "o", "r", 999, gitea.EditIssueArgs{Title: &title})
	require.Error(t, err)
	assert.ErrorIs(t, err, gitea.ErrNotFound)
}

func TestCreateIssueComment(t *testing.T) {
	var captured []byte
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, "/api/v1/repos/o/r/issues/42/comments", r.URL.Path)
		assert.Equal(t, http.MethodPost, r.Method)
		var err error
		captured, err = io.ReadAll(r.Body)
		require.NoError(t, err)
		w.WriteHeader(http.StatusCreated)
		_, _ = w.Write([]byte(`{"id":7,"body":"hello","html_url":"http://example.com/issues/42#comment-7"}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	comment, err := c.CreateIssueComment(context.Background(), "o", "r", 42, "hello")
	require.NoError(t, err)

	var payload map[string]any
	require.NoError(t, json.Unmarshal(captured, &payload))
	assert.Equal(t, "hello", payload["body"])

	assert.Equal(t, int64(7), comment.ID)
	assert.Equal(t, "hello", comment.Body)
	assert.Equal(t, "http://example.com/issues/42#comment-7", comment.HTMLURL)
}

func TestListIssueComments(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, http.MethodGet, r.Method)
		assert.Equal(t, "/api/v1/repos/o/r/issues/42/comments", r.URL.Path)
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`[
			{"id":1,"body":"first","html_url":"http://example.com/issues/42#comment-1","user":{"login":"alice"},"created_at":"2026-05-01T00:00:00Z","updated_at":"2026-05-01T00:00:00Z"},
			{"id":2,"body":"second","html_url":"http://example.com/issues/42#comment-2","user":{"login":"bob"},"created_at":"2026-05-02T00:00:00Z","updated_at":"2026-05-02T00:00:00Z"}
		]`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	comments, err := c.ListIssueComments(context.Background(), "o", "r", 42)
	require.NoError(t, err)
	require.Len(t, comments, 2)
	assert.Equal(t, int64(1), comments[0].ID)
	assert.Equal(t, "first", comments[0].Body)
	assert.Equal(t, "alice", comments[0].User.Login)
	assert.Equal(t, "bob", comments[1].User.Login)
}

func TestListIssueComments_Empty(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`[]`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	comments, err := c.ListIssueComments(context.Background(), "o", "r", 42)
	require.NoError(t, err)
	assert.Empty(t, comments)
}

func TestListIssueComments_NotFound(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusNotFound)
		_, _ = w.Write([]byte(`{"message":"issue not found"}`))
	}))
	defer srv.Close()

	c := gitea.NewClient(srv.URL, "tok")
	_, err := c.ListIssueComments(context.Background(), "o", "r", 999)
	require.Error(t, err)
	assert.ErrorIs(t, err, gitea.ErrNotFound)
}