package commands

import (
	"bytes"
	"fmt"
	"io"

	key "github.com/ipfs/go-ipfs/blocks/key"
	cmds "github.com/ipfs/go-ipfs/commands"
	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
	core "github.com/ipfs/go-ipfs/core"
	corerepo "github.com/ipfs/go-ipfs/core/corerepo"
	dag "github.com/ipfs/go-ipfs/merkledag"
	path "github.com/ipfs/go-ipfs/path"
	u "github.com/ipfs/go-ipfs/util"
)

var PinCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Pin (and unpin) objects to local storage",
	},

	Subcommands: map[string]*cmds.Command{
		"add": addPinCmd,
		"rm":  rmPinCmd,
		"ls":  listPinCmd,
	},
}

type PinOutput struct {
	Pinned []key.Key
}

var addPinCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Pins objects to local storage",
		ShortDescription: `
Retrieves the object named by <ipfs-path> and stores it locally
on disk.
`,
	},

	Arguments: []cmds.Argument{
		cmds.StringArg("ipfs-path", true, true, "Path to object(s) to be pinned").EnableStdin(),
	},
	Options: []cmds.Option{
		cmds.BoolOption("recursive", "r", "Recursively pin the object linked to by the specified object(s)"),
	},
	Type: PinOutput{},
	Run: func(req cmds.Request, res cmds.Response) {
		n, err := req.InvocContext().GetNode()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}

		unlock := n.Blockstore.PinLock()
		defer unlock()

		// set recursive flag
		recursive, found, err := req.Option("recursive").Bool()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}
		if !found {
			recursive = true
		}

		added, err := corerepo.Pin(n, req.Context(), req.Arguments(), recursive)
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}

		res.SetOutput(&PinOutput{added})
	},
	Marshalers: cmds.MarshalerMap{
		cmds.Text: func(res cmds.Response) (io.Reader, error) {
			added, ok := res.Output().(*PinOutput)
			if !ok {
				return nil, u.ErrCast()
			}

			var pintype string
			rec, found, _ := res.Request().Option("recursive").Bool()
			if rec || !found {
				pintype = "recursively"
			} else {
				pintype = "directly"
			}

			buf := new(bytes.Buffer)
			for _, k := range added.Pinned {
				fmt.Fprintf(buf, "pinned %s %s\n", k, pintype)
			}
			return buf, nil
		},
	},
}

var rmPinCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Removes the pinned object from local storage. (By default, recursively. Use -r=false for direct pins)",
		ShortDescription: `
Removes the pin from the given object allowing it to be garbage
collected if needed. (By default, recursively. Use -r=false for direct pins)
`,
	},

	Arguments: []cmds.Argument{
		cmds.StringArg("ipfs-path", true, true, "Path to object(s) to be unpinned").EnableStdin(),
	},
	Options: []cmds.Option{
		cmds.BoolOption("recursive", "r", "Recursively unpin the object linked to by the specified object(s)"),
	},
	Type: PinOutput{},
	Run: func(req cmds.Request, res cmds.Response) {
		n, err := req.InvocContext().GetNode()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}

		// set recursive flag
		recursive, found, err := req.Option("recursive").Bool()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}
		if !found {
			recursive = true // default
		}

		removed, err := corerepo.Unpin(n, req.Context(), req.Arguments(), recursive)
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}

		res.SetOutput(&PinOutput{removed})
	},
	Marshalers: cmds.MarshalerMap{
		cmds.Text: func(res cmds.Response) (io.Reader, error) {
			added, ok := res.Output().(*PinOutput)
			if !ok {
				return nil, u.ErrCast()
			}

			buf := new(bytes.Buffer)
			for _, k := range added.Pinned {
				fmt.Fprintf(buf, "unpinned %s\n", k)
			}
			return buf, nil
		},
	},
}

var listPinCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "List objects pinned to local storage",
		ShortDescription: `
Returns a list of objects that are pinned locally.
Without arguments, by default, only recursively pinned objects are returned, but others may be shown via the '--type' flag.
`,
		LongDescription: `
Returns a list of objects that are pinned locally.
Without arguments, by default, only recursively pinned objects are returned, but others may be shown via the '--type' flag.

Use --type=<type> to specify the type of pinned keys to list. Valid values are:
    * "direct": pin that specific object.
    * "recursive": pin that specific object, and indirectly pin all its decendants
    * "indirect": pinned indirectly by an ancestor (like a refcount)
    * "all"

With arguments, the command fails if any of the arguments is not a pinned object.
And if --type=<type> is additionally used, the command will also fail if any of the arguments is not of the specified type.

Example:
	$ echo "hello" | ipfs add -q
	QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN
	$ ipfs pin ls
	QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN recursive
	# now remove the pin, and repin it directly
	$ ipfs pin rm QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN
	unpinned QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN
	$ ipfs pin add -r=false QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN
	pinned QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN directly
	$ ipfs pin ls --type=direct
	QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN direct
	$ ipfs pin ls QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN
	QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN direct
`,
	},

	Arguments: []cmds.Argument{
		cmds.StringArg("ipfs-path", false, true, "Path to object(s) to be listed"),
	},
	Options: []cmds.Option{
		cmds.StringOption("type", "t", "The type of pinned keys to list. Can be \"direct\", \"indirect\", \"recursive\", or \"all\". Defaults to \"recursive\""),
		cmds.BoolOption("count", "n", "Show refcount when listing indirect pins"),
		cmds.BoolOption("quiet", "q", "Write just hashes of objects"),
	},
	Run: func(req cmds.Request, res cmds.Response) {
		n, err := req.InvocContext().GetNode()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}

		typeStr, typeStrFound, err := req.Option("type").String()
		if err != nil {
			res.SetError(err, cmds.ErrNormal)
			return
		}

		if typeStrFound {
			switch typeStr {
			case "all", "direct", "indirect", "recursive":
			default:
				err = fmt.Errorf("Invalid type '%s', must be one of {direct, indirect, recursive, all}", typeStr)
				res.SetError(err, cmds.ErrClient)
				return
			}
		}

		var keys map[string]RefKeyObject

		if len(req.Arguments()) > 0 {
			if !typeStrFound {
				typeStr = "all"
			}

			keys, err = pinLsKeys(req.Arguments(), typeStr, req.Context(), n)
		} else {
			if !typeStrFound {
				typeStr = "recursive"
			}

			keys, err = pinLsAll(typeStr, req.Context(), n)
		}

		if err != nil {
			res.SetError(err, cmds.ErrNormal)
		} else {
			res.SetOutput(&RefKeyList{Keys: keys})
		}
	},
	Type: RefKeyList{},
	Marshalers: cmds.MarshalerMap{
		cmds.Text: func(res cmds.Response) (io.Reader, error) {
			quiet, _, err := res.Request().Option("quiet").Bool()
			if err != nil {
				return nil, err
			}

			keys, ok := res.Output().(*RefKeyList)
			if !ok {
				return nil, u.ErrCast()
			}
			out := new(bytes.Buffer)
			for k, v := range keys.Keys {
				if quiet {
					fmt.Fprintf(out, "%s\n", k)
				} else {
					fmt.Fprintf(out, "%s %s\n", k, v.Type)
				}
			}
			return out, nil
		},
	},
}

type RefKeyObject struct {
	Type string
}

type RefKeyList struct {
	Keys map[string]RefKeyObject
}

func pinLsKeys(args []string, typeStr string, ctx context.Context, n *core.IpfsNode) (map[string]RefKeyObject, error) {

	keys := make(map[string]RefKeyObject)

	for _, p := range args {
		dagNode, err := core.Resolve(ctx, n, path.Path(p))
		if err != nil {
			return nil, err
		}

		k, err := dagNode.Key()
		if err != nil {
			return nil, err
		}

		pinType, pinned, err := n.Pinning.IsPinnedWithType(k, typeStr)
		if err != nil {
			return nil, err
		}

		if !pinned {
			return nil, fmt.Errorf("Path '%s' is not pinned", p)
		}

		switch pinType {
		case "direct", "indirect", "recursive", "internal":
		default:
			pinType = "indirect through " + pinType
		}
		keys[k.B58String()] = RefKeyObject{
			Type: pinType,
		}
	}

	return keys, nil
}

func pinLsAll(typeStr string, ctx context.Context, n *core.IpfsNode) (map[string]RefKeyObject, error) {

	keys := make(map[string]RefKeyObject)

	AddToResultKeys := func(keyList []key.Key, typeStr string) {
		for _, k := range keyList {
			keys[k.B58String()] = RefKeyObject{
				Type: typeStr,
			}
		}
	}

	if typeStr == "direct" || typeStr == "all" {
		AddToResultKeys(n.Pinning.DirectKeys(), "direct")
	}
	if typeStr == "indirect" || typeStr == "all" {
		ks := key.NewKeySet()
		for _, k := range n.Pinning.RecursiveKeys() {
			nd, err := n.DAG.Get(ctx, k)
			if err != nil {
				return nil, err
			}
			err = dag.EnumerateChildren(n.Context(), n.DAG, nd, ks)
			if err != nil {
				return nil, err
			}
		}
		AddToResultKeys(ks.Keys(), "indirect")
	}
	if typeStr == "recursive" || typeStr == "all" {
		AddToResultKeys(n.Pinning.RecursiveKeys(), "recursive")
	}

	return keys, nil
}