// Copyright 2014 The Gogs Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package middleware

import (
	"fmt"
	"html/template"
	"io"
	"net/http"
	"strings"
	"time"

	"github.com/go-macaron/cache"
	"github.com/go-macaron/csrf"
	"github.com/go-macaron/i18n"
	"github.com/go-macaron/session"
	"gopkg.in/macaron.v1"

	"github.com/gogits/git-module"

	"github.com/gogits/gogs/models"
	"github.com/gogits/gogs/modules/auth"
	"github.com/gogits/gogs/modules/base"
	"github.com/gogits/gogs/modules/log"
	"github.com/gogits/gogs/modules/setting"
)

type RepoContext struct {
	AccessMode   models.AccessMode
	IsWatching   bool
	IsViewBranch bool
	IsViewTag    bool
	IsViewCommit bool
	Repository   *models.Repository
	Owner        *models.User
	Commit       *git.Commit
	Tag          *git.Tag
	GitRepo      *git.Repository
	BranchName   string
	TagName      string
	TreeName     string
	CommitID     string
	RepoLink     string
	CloneLink    models.CloneLink
	CommitsCount int64
	Mirror       *models.Mirror
}

// Context represents context of a request.
type Context struct {
	*macaron.Context
	Cache   cache.Cache
	csrf    csrf.CSRF
	Flash   *session.Flash
	Session session.Store

	User        *models.User
	IsSigned    bool
	IsBasicAuth bool

	Repo *RepoContext

	Org struct {
		IsOwner      bool
		IsMember     bool
		IsAdminTeam  bool // In owner team or team that has admin permission level.
		Organization *models.User
		OrgLink      string

		Team *models.Team
	}
}

// IsOwner returns true if current user is the owner of repository.
func (r *RepoContext) IsOwner() bool {
	return r.AccessMode >= models.ACCESS_MODE_OWNER
}

// IsAdmin returns true if current user has admin or higher access of repository.
func (r *RepoContext) IsAdmin() bool {
	return r.AccessMode >= models.ACCESS_MODE_ADMIN
}

// IsPusher returns true if current user has write or higher access of repository.
func (r *RepoContext) IsPusher() bool {
	return r.AccessMode >= models.ACCESS_MODE_WRITE
}

// Return if the current user has read access for this repository
func (r *RepoContext) HasAccess() bool {
	return r.AccessMode >= models.ACCESS_MODE_READ
}

// HasError returns true if error occurs in form validation.
func (ctx *Context) HasApiError() bool {
	hasErr, ok := ctx.Data["HasError"]
	if !ok {
		return false
	}
	return hasErr.(bool)
}

func (ctx *Context) GetErrMsg() string {
	return ctx.Data["ErrorMsg"].(string)
}

// HasError returns true if error occurs in form validation.
func (ctx *Context) HasError() bool {
	hasErr, ok := ctx.Data["HasError"]
	if !ok {
		return false
	}
	ctx.Flash.ErrorMsg = ctx.Data["ErrorMsg"].(string)
	ctx.Data["Flash"] = ctx.Flash
	return hasErr.(bool)
}

// HasValue returns true if value of given name exists.
func (ctx *Context) HasValue(name string) bool {
	_, ok := ctx.Data[name]
	return ok
}

// HTML calls Context.HTML and converts template name to string.
func (ctx *Context) HTML(status int, name base.TplName) {
	log.Debug("Template: %s", name)
	ctx.Context.HTML(status, string(name))
}

// RenderWithErr used for page has form validation but need to prompt error to users.
func (ctx *Context) RenderWithErr(msg string, tpl base.TplName, form interface{}) {
	if form != nil {
		auth.AssignForm(form, ctx.Data)
	}
	ctx.Flash.ErrorMsg = msg
	ctx.Data["Flash"] = ctx.Flash
	ctx.HTML(200, tpl)
}

// Handle handles and logs error by given status.
func (ctx *Context) Handle(status int, title string, err error) {
	if err != nil {
		log.Error(4, "%s: %v", title, err)
		if macaron.Env != macaron.PROD {
			ctx.Data["ErrorMsg"] = err
		}
	}

	switch status {
	case 404:
		ctx.Data["Title"] = "Page Not Found"
	case 500:
		ctx.Data["Title"] = "Internal Server Error"
	}
	ctx.HTML(status, base.TplName(fmt.Sprintf("status/%d", status)))
}

func (ctx *Context) HandleText(status int, title string) {
	if (status/100 == 4) || (status/100 == 5) {
		log.Error(4, "%s", title)
	}
	ctx.PlainText(status, []byte(title))
}

// APIError logs error with title if status is 500.
func (ctx *Context) APIError(status int, title string, obj interface{}) {
	var message string
	if err, ok := obj.(error); ok {
		message = err.Error()
	} else {
		message = obj.(string)
	}

	if status == 500 {
		log.Error(4, "%s: %s", title, message)
	}

	ctx.JSON(status, map[string]string{
		"message": message,
		"url":     base.DOC_URL,
	})
}

func (ctx *Context) ServeContent(name string, r io.ReadSeeker, params ...interface{}) {
	modtime := time.Now()
	for _, p := range params {
		switch v := p.(type) {
		case time.Time:
			modtime = v
		}
	}
	ctx.Resp.Header().Set("Content-Description", "File Transfer")
	ctx.Resp.Header().Set("Content-Type", "application/octet-stream")
	ctx.Resp.Header().Set("Content-Disposition", "attachment; filename="+name)
	ctx.Resp.Header().Set("Content-Transfer-Encoding", "binary")
	ctx.Resp.Header().Set("Expires", "0")
	ctx.Resp.Header().Set("Cache-Control", "must-revalidate")
	ctx.Resp.Header().Set("Pragma", "public")
	http.ServeContent(ctx.Resp, ctx.Req.Request, name, modtime, r)
}

// Contexter initializes a classic context for a request.
func Contexter() macaron.Handler {
	return func(c *macaron.Context, l i18n.Locale, cache cache.Cache, sess session.Store, f *session.Flash, x csrf.CSRF) {
		ctx := &Context{
			Context: c,
			Cache:   cache,
			csrf:    x,
			Flash:   f,
			Session: sess,
			Repo:    &RepoContext{},
		}
		// Compute current URL for real-time change language.
		ctx.Data["Link"] = setting.AppSubUrl + strings.TrimSuffix(ctx.Req.URL.Path, "/")

		ctx.Data["PageStartTime"] = time.Now()

		// Get user from session if logined.
		ctx.User, ctx.IsBasicAuth = auth.SignedInUser(ctx.Context, ctx.Session)

		if ctx.User != nil {
			ctx.IsSigned = true
			ctx.Data["IsSigned"] = ctx.IsSigned
			ctx.Data["SignedUser"] = ctx.User
			ctx.Data["SignedUserID"] = ctx.User.Id
			ctx.Data["SignedUserName"] = ctx.User.Name
			ctx.Data["IsAdmin"] = ctx.User.IsAdmin
		} else {
			ctx.Data["SignedUserID"] = 0
			ctx.Data["SignedUserName"] = ""
		}

		// If request sends files, parse them here otherwise the Query() can't be parsed and the CsrfToken will be invalid.
		if ctx.Req.Method == "POST" && strings.Contains(ctx.Req.Header.Get("Content-Type"), "multipart/form-data") {
			if err := ctx.Req.ParseMultipartForm(setting.AttachmentMaxSize << 20); err != nil && !strings.Contains(err.Error(), "EOF") { // 32MB max size
				ctx.Handle(500, "ParseMultipartForm", err)
				return
			}
		}

		ctx.Data["CsrfToken"] = x.GetToken()
		ctx.Data["CsrfTokenHtml"] = template.HTML(`<input type="hidden" name="_csrf" value="` + x.GetToken() + `">`)
		log.Debug("Session ID: %s", sess.ID())
		log.Debug("CSRF Token: %v", ctx.Data["CsrfToken"])

		ctx.Data["ShowRegistrationButton"] = setting.Service.ShowRegistrationButton
		ctx.Data["ShowFooterBranding"] = setting.ShowFooterBranding
		ctx.Data["ShowFooterVersion"] = setting.ShowFooterVersion

		c.Map(ctx)
	}
}