1 files changed, 189 insertions, 40 deletions

diff --git a/src/nissy.h b/src/nissy.h
index c78fb50..c019998 100644
--- a/src/nissy.h
+++ b/src/nissy.h
@@ -8,10 +8,9 @@ If you include this file, you should also use the following includes:
 #include <stdbool>
 #include <string>
 
-All the functions below return 0 in case of success and a positive number
-in case of error, unless otherwise specified. Errors are checked in code
-order: for example if error code 1 is returned then it could that also
-an error with code 2 or higher occurred.
+All the functions return 0 or a positive integer in case of success and
+a negative integer in case of error, unless otherwise specified.
+You can see the list of error codes below, or use nissy_explainerror().
 
 Arguments of type char [static 22] denote a cube in B32 format.
 Other available formats are H48 and SRC. See README.md for more info on
@@ -25,14 +24,48 @@ A transformation must be given in the format
 for example 'rotation UF' or 'mirrored BL'.
 */
 
+/* Error codes */
+#define NISSY_OK                     INT64_C(0)
+#define NISSY_WARNING_UNSOLVABLE     INT64_C(-1)
+#define NISSY_WARNING_NULL_CALLBACK  INT64_C(-2)
+#define NISSY_ERROR_INVALID_CUBE     INT64_C(-10)
+#define NISSY_ERROR_UNSOLVABLE_CUBE  INT64_C(-11)
+#define NISSY_ERROR_INVALID_MOVES    INT64_C(-20)
+#define NISSY_ERROR_INVALID_TRANS    INT64_C(-30)
+#define NISSY_ERROR_INVALID_FORMAT   INT64_C(-40)
+#define NISSY_ERROR_INVALID_SOLVER   INT64_C(-50)
+#define NISSY_ERROR_NULL_POINTER     INT64_C(-60)
+#define NISSY_ERROR_DATA             INT64_C(-70)
+#define NISSY_ERROR_OPTIONS          INT64_C(-80)
+#define NISSY_ERROR_INVALID_CODE     INT64_C(-90)
+#define NISSY_ERROR_UNKNOWN          INT64_C(-999)
+
+/* Flags for NISS options */
+#define NISSY_NISSFLAG_NORMAL  UINT8_C(1)
+#define NISSY_NISSFLAG_INVERSE UINT8_C(2)
+#define NISSY_NISSFLAG_MIXED   UINT8_C(4)
+#define NISSY_NISSFLAG_LINEAR  \
+    (NISSY_NISSFLAG_NORMAL | NISSY_NISSFLAG_INVERSE)
+#define NISSY_NISSFLAG_ALL     \
+    (NISSY_NISSFLAG_NORMAL | NISSY_NISSFLAG_INVERSE | NISSY_NISSFLAG_MIXED)
+
 /*
 Apply the secod argument as a permutation on the first argument.
 
+Parameters:
+   cube        - The first cube, in B32 format.
+   permutation - The second cube, in B32 format. This cube is treated as a
+                 permutation and "applied" to the first cube.
+   result      - The return parameter for the resulting cube, in B32 format.
+
 Return values:
-   0    Valid result
-   1    The given cube is invalid
-   2    The given permutation is invalid
-   9    The resulting cube is not solvable
+   NISSY_OK                  - The cubes were composed succesfully.
+   NISSY_WARNING_UNSOLVABLE  - The resulting cube is not solvable. This is
+                               either because at least on of the given cubes
+                               was not solvable, or due to an unknown internal
+                               error.
+   NISSY_ERROR_INVALID_CUBE  - At least one of the given cubes is invalid.
+   NISSY_ERROR_UNKNOWN       - An unknown error occurred.
 */
 int64_t nissy_compose(
         const char cube[static 22],
@@ -43,10 +76,17 @@ int64_t nissy_compose(
 /*
 Compute the inverse of the given cube.
 
+Parameters:
+   cube   - The cube to be inverted, in B32 format.
+   result - The return parameter for the resulting cube, in B32 format.
+
 Return values:
-   0    Valid result
-   1    The given cube is invalid
-   9    The resulting cube is not solvable
+   NISSY_OK                  - The cube was inverted succesfully.
+   NISSY_WARNING_UNSOLVABLE  - The resulting cube is not solvable. This is
+                               either because the given cube was not solvable,
+                               or due to an unknown internal error.
+   NISSY_ERROR_INVALID_CUBE  - The given cube is invalid.
+   NISSY_ERROR_UNKNOWN       - An unknown error occurred.
 */
 int64_t nissy_inverse(
         const char cube[static 22],
@@ -56,11 +96,18 @@ int64_t nissy_inverse(
 /*
 Apply the given sequence of moves on the given cube.
 
+Parameters:
+   cube   - The cube to move, in B32 format.
+   moves  - The moves to apply to the cube.
+   result - The return parameter for the resulting cube, in B32 format.
+
 Return values:
-   0    Valid result
-   1    The given cube is invalid
-   8    The given moves are invalid
-   9    The resulting cube is not solvable
+   NISSY_OK                  - The moves were applied succesfully.
+   NISSY_WARNING_UNSOLVABLE  - The resulting cube is not solvable. This is
+                               either because the given cube was not solvable,
+                               or due to an unknown internal error.
+   NISSY_ERROR_INVALID_CUBE  - The given cube is invalid.
+   NISSY_ERROR_INVALID_MOVES - The given moves are invalid.
 */
 int64_t nissy_applymoves(
         const char cube[static 22],
@@ -71,11 +118,17 @@ int64_t nissy_applymoves(
 /*
 Apply the single given transformation to the given cube.
 
+Parameters:
+   cube           - The cube to be transformed, in B32 format.
+   transformation - The transformation in (rotation|mirrored) xy format.
+   result         - The return parameter for the resulting cube, in B32 format.
+
 Return values:
-   0    Valid result
-   1    The given cube is invalid
-   8    The given transformation is invalid
-   9    The resulting cube is not solvable
+   NISSY_OK                  - The transformation was performed succesfully.
+   NISSY_WARNING_UNSOLVABLE  - The resulting cube is not solvable. This is
+                               probably due to an unknown internal error.
+   NISSY_ERROR_INVALID_CUBE  - The given cube is invalid.
+   NISSY_ERROR_INVALID_TRANS - The given transformation is invalid.
 */
 int64_t nissy_applytrans(
         const char cube[static 22],
@@ -86,9 +139,15 @@ int64_t nissy_applytrans(
 /*
 Apply the given moves to the solved cube.
 
+Parameters:
+   moves  - The moves to be applied to the solved cube.
+   result - Return parameter for the resulting cube, in B32 format.
+
 Return values:
-   0    Valid result
-   1    The given moves are invalid
+   NISSY_OK                  - The moves were performed succesfully.
+   NISSY_WARNING_UNSOLVABLE  - The resulting cube is not solvable. This is
+                               probably due to an unknown internal error.
+   NISSY_ERROR_INVALID_MOVES - The given moves are invalid.
 */
 int64_t nissy_frommoves(
         const char *moves,
@@ -98,20 +157,45 @@ int64_t nissy_frommoves(
 /*
 Convert the given cube between the two given formats.
 
+Parameters:
+   format_in  - The input format.
+   format_out - The output format.
+   string     - The cube, in format_in format.
+   result     - Return parameter for the cube in format_out format. Must be
+                large enough to contains the cube in this format.
+
 Return values:
-   0    Valid result
-   1    The given cube or format_in is invalid
-   2    The resulting cube or format_out is invalid
-   3    The resulting cube is inconsistent
+   NISSY_OK                   - The conversion was performed succesfully.
+   NISSY_ERROR_INVALID_CUBE   - The given cube is invalid.
+   NISSY_ERROR_INVALID_FORMAT - At least one of the given formats is invalid.
+   NISSY_ERROR_UNKNOWN        - An unknown error occurred.
 */
 int64_t nissy_convert(
         const char *format_in,
         const char *format_out,
-        const char *cube_string,
+        const char *cube,
         char *result
 );
 
-/* Get the cube with the given ep, eo, cp and co values. */
+/*
+Get the cube with the given ep, eo, cp and co values. The values must be in the
+ranges specified below, but if the option "fix" is given any values outside its
+range will be adjusted before using it. The option "fix" also fixes parity and
+orientation issues, resulting always in a solvable cube.
+
+Parameters:
+   ep      - The edge permutation, 0 <= ep <= 479001600 (12!)
+   eo      - The edge orientation, 0 <= eo <= 2047 (2^11)
+   cp      - The corner permutation, 0 <= cp <= 40320 (8!)
+   co      - The corner orientation, 0 <= co <= 2187 (3^7)
+   options - Other options.
+   result  - The return parameter for the resulting cube, in B32 format.
+
+Return values:
+   NISSY_OK                 - The cube was generated succesfully.
+   NISSY_WARNING_UNSOLVABLE - The resulting cube is unsolvable.
+   NISSY_ERROR_OPTIONS      - One or more of the given parameters is invalid.
+*/
 int64_t nissy_getcube(
         int64_t ep,
         int64_t eo,
@@ -125,9 +209,13 @@ int64_t nissy_getcube(
 Compute the size of the data generated by nissy_gendata, when called with
 the same parameters, or -1 in case of error.
 
+Parameters:
+   solver - The name of the solver.
+
 Return values:
-   -1   Error
-   >=0  The size of the table, in bytes
+   NISSY_ERROR_INVALID_SOLVER - The given solver is not known.
+   NISSY_ERROR_UNKNOWN        - An unknown error occurred.
+   Any value >= 0             - The size of the data, in bytes.
 */
 int64_t nissy_datasize(
         const char *solver
@@ -136,38 +224,71 @@ int64_t nissy_datasize(
 /*
 Compute the data for the given solver and store it in generated_data.
 
+Parameters:
+   solver - The name of the solver.
+   data   - The return parameter for the generated data. Must be large enoguh
+            to contain the whole data. It is advised to use nissy_datasize to
+            check how much memory is needed.
+
 Return values:
-   -1   Error
-   >=0  The size of the table, in bytes
+   NISSY_ERROR_INVALID_SOLVER - The given solver is not known.
+   NISSY_ERROR_UNKNOWN        - An error occurred while generating the data.
+   Any value >= 0             - The size of the data, in bytes.
 */
 int64_t nissy_gendata(
         const char *solver,
-        void *generated_data
+        void *data
 );
 
 /*
 Print information on a data table via the provided callback writer.
 
+Parameters:
+   data  - The data 
+   write - A callback writer with the same signature as printf(3).
+
 Return values:
-   0    No error
-   1    The given data could not be read correctly
+   NISSY_OK         - The data is correct.
+   NISSY_ERROR_DATA - The data contains errors.
 */
 int64_t nissy_datainfo(
-        const void *table,
+        const void *data,
         void (*write)(const char *, ...)
 );
 
 /*
-Solve the given cube using the given solver and options
+Solve the given cube using the given solver and options.
+
+Parameters:
+   cube         - The cube to solver, in B32 format.
+   solver       - The name of the solver.
+   nissflag     - The flags for NISS (linear, inverse, mixed, or combinations).
+   minmoves     - The minimum number of moves for a solution.
+   maxmoves     - The maximum number of moves for a solution.
+   maxsolutions - The maximum number of solutions.
+   optimal      - If set to a non-negative value, the maximum number of moves
+                  above the optimal solution length.
+   data         - The data for the solver. Can be computed with gendata.
+   solutions    - The return parameter for the solutions. Must be large enough
+                  to store all found solutions. The solutions are separated by
+                  a '\n' (newline) and a '\0' (NULL character) terminates the
+                  list.
+                  TODO: replace with callback writer.
 
 Return values:
-   -1   Error
-   >=0  The number of solutions found
+   NISSY_OK                    - Cube solved succesfully.
+   NISSY_ERROR_INVALID_CUBE    - The given cube is invalid.
+   NISSY_ERROR_UNSOLVABLE_CUBE - The given cube is valid, but not solvable with
+                                 the given solver.
+   NISSY_ERROR_OPTIONS         - One or more of the given options are invalid.
+   NISSY_ERROR_NULL_POINTER    - One of the provided pointers is null.
+   NISSY_ERROR_INVALID_SOLVER  - The given solver is not known.
+   Any value >= 0              - The number of solutions found.
 */
 int64_t nissy_solve(
         const char cube[static 22],
         const char *solver, 
-        const char *nisstype, /* TODO: remove, use flags */
+        uint8_t nissflag,
         int8_t minmoves,
         int8_t maxmoves,
         int64_t maxsolutions,
@@ -178,5 +299,33 @@ int64_t nissy_solve(
 
 /*
 Set a global logger function used by this library.
+
+Parameters:
+   write - A callback writer with the same signature as printf(3).
+
+Return values:
+   NISSY_OK                    - Logger set succesfully.
+   NISSY_WARNING_NULL_CALLBACK - The provided callback writer is NULL.
 */
-void nissy_setlogger(void (*logger_function)(const char *, ...));
+int64_t nissy_setlogger(
+        void (*logger_function)(const char *, ...)
+);
+
+/*
+Print an explanation of the given error code via the provided callback writer.
+
+Parameters:
+   error_code - The error code to be explained. It can be any value returned
+                by a function in this library, not necessarily an error.
+   write      - A callback writer with the same signature as printf(3).
+                Must be non-NULL.
+
+Return values:
+   NISSY_OK                    - The error code is known.
+   NISSY_WARNING_NULL_CALLBACK - The provided callback writer is NULL.
+   NISSY_ERROR_INVALID_CODE    - The error code is unknown.
+*/
+int64_t nissy_explainerror(
+        int64_t error_code,
+        void (*write)(const char *, ...)
+);