// MIT License

// Copyright (c) 2017 Leslie Zheng

// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

package echopprof

import (
	"net/http/pprof"
	"strings"

	"github.com/labstack/echo/v4"
)

// Wrap adds several routes from package `net/http/pprof` to *echo.Echo object.
func Wrap(e *echo.Echo) {
	WrapGroup("", e.Group("/debug/pprof"))
}

// Wrapper make sure we are backward compatible.
var Wrapper = Wrap

// WrapGroup adds several routes from package `net/http/pprof` to *echo.Group object.
func WrapGroup(prefix string, g *echo.Group) {
	routers := []struct {
		Method  string
		Path    string
		Handler echo.HandlerFunc
	}{
		{"GET", "", IndexHandler()},
		{"GET", "/", IndexHandler()},
		{"GET", "/heap", HeapHandler()},
		{"GET", "/goroutine", GoroutineHandler()},
		{"GET", "/block", BlockHandler()},
		{"GET", "/threadcreate", ThreadCreateHandler()},
		{"GET", "/cmdline", CmdlineHandler()},
		{"GET", "/profile", ProfileHandler()},
		{"GET", "/symbol", SymbolHandler()},
		{"POST", "/symbol", SymbolHandler()},
		{"GET", "/trace", TraceHandler()},
		{"GET", "/mutex", MutexHandler()},
		{"GET", "/allocs", AllocsHandler()},
	}

	for _, r := range routers {
		switch r.Method {
		case "GET":
			g.GET(strings.TrimPrefix(r.Path, prefix), r.Handler)
		case "POST":
			g.POST(strings.TrimPrefix(r.Path, prefix), r.Handler)
		}
	}
}

// IndexHandler will pass the call from /debug/pprof to pprof.
func IndexHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Index(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// HeapHandler will pass the call from /debug/pprof/heap to pprof.
func HeapHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Handler("heap").ServeHTTP(ctx.Response(), ctx.Request())
		return nil
	}
}

// GoroutineHandler will pass the call from /debug/pprof/goroutine to pprof.
func GoroutineHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Handler("goroutine").ServeHTTP(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// BlockHandler will pass the call from /debug/pprof/block to pprof.
func BlockHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Handler("block").ServeHTTP(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// ThreadCreateHandler will pass the call from /debug/pprof/threadcreate to pprof.
func ThreadCreateHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Handler("threadcreate").ServeHTTP(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// CmdlineHandler will pass the call from /debug/pprof/cmdline to pprof.
func CmdlineHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Cmdline(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// ProfileHandler will pass the call from /debug/pprof/profile to pprof.
func ProfileHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Profile(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// SymbolHandler will pass the call from /debug/pprof/symbol to pprof.
func SymbolHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Symbol(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// TraceHandler will pass the call from /debug/pprof/trace to pprof.
func TraceHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Trace(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// MutexHandler will pass the call from /debug/pprof/mutex to pprof.
func MutexHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Handler("mutex").ServeHTTP(ctx.Response().Writer, ctx.Request())
		return nil
	}
}

// AllocsHandler will pass the call from /debug/pprof/allocs to pprof.
func AllocsHandler() echo.HandlerFunc {
	return func(ctx echo.Context) error {
		pprof.Handler("allocs").ServeHTTP(ctx.Response().Writer, ctx.Request())
		return nil
	}
}